[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>

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<BLOCK_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)*BLOCK_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, int block)
{
	struct super_block * sb = inode->i_sb;
	struct minix_sb_info * sbi = minix_sb(sb);
	struct buffer_head * bh;
	unsigned int 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 & 8191;
	zone >>= 13;
	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("free_block (%s:%d): 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 i;

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

		lock_kernel();
		if ((j = minix_find_first_zero_bit(bh->b_data, 8192)) < 8192) {
			minix_set_bit(j,bh->b_data);
			unlock_kernel();
			mark_buffer_dirty(bh);
			j += i*8192 + 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;

	*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 minix_sb_info *sbi = minix_sb(inode->i_sb);
	struct buffer_head * bh;
	unsigned long ino;

	ino = inode->i_ino;
	if (ino < 1 || ino > sbi->s_ninodes) {
		printk("minix_free_inode: inode 0 or nonexistent inode\n");
		goto out;
	}
	if ((ino >> 13) >= 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 >> 13];
	lock_kernel();
	if (!minix_test_and_clear_bit(ino & 8191, bh->b_data))
		printk("minix_free_inode: bit %lu already cleared\n", ino);
	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 i,j;

	if (!inode) {
		*error = -ENOMEM;
		return NULL;
	}
	j = 8192;
	bh = NULL;
	*error = -ENOSPC;
	lock_kernel();
	for (i = 0; i < sbi->s_imap_blocks; i++) {
		bh = sbi->s_imap[i];
		if ((j = minix_find_first_zero_bit(bh->b_data, 8192)) < 8192)
			break;
	}
	if (!bh || j >= 8192) {
		unlock_kernel();
		iput(inode);
		return NULL;
	}
	if (minix_test_and_set_bit(j,bh->b_data)) {	/* shouldn't happen */
		printk("new_inode: bit already set\n");
		unlock_kernel();
		iput(inode);
		return NULL;
	}
	unlock_kernel();
	mark_buffer_dirty(bh);
	j += i*8192;
	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);
	29	for (j=0; j<BLOCK_SIZE; j++)
	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);
	36	i = ((numbits-(numblocks-1)BLOCK_SIZE8)/16)*2;
	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
	51	void minix_free_block(struct inode * inode, int block)
	52	{
	53	struct super_block * sb = inode->i_sb;
	54	struct minix_sb_info * sbi = minix_sb(sb);
	55	struct buffer_head * bh;
	56	unsigned int bit,zone;
	57
	58	if (block < sbi->s_firstdatazone \|\| block >= sbi->s_nzones) {
11b84487	59	printk("Trying to free block not in datazone\n");
1da177e4 LT	60	return;
	61	}
	62	zone = block - sbi->s_firstdatazone + 1;
	63	bit = zone & 8191;
	64	zone >>= 13;
	65	if (zone >= sbi->s_zmap_blocks) {
	66	printk("minix_free_block: nonexistent bitmap buffer\n");
	67	return;
	68	}
	69	bh = sbi->s_zmap[zone];
	70	lock_kernel();
	71	if (!minix_test_and_clear_bit(bit,bh->b_data))
	72	printk("free_block (%s:%d): bit already cleared\n",
	73	sb->s_id, block);
	74	unlock_kernel();
	75	mark_buffer_dirty(bh);
	76	return;
	77	}
	78
	79	int minix_new_block(struct inode * inode)
	80	{
	81	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
	82	int i;
	83
	84	for (i = 0; i < sbi->s_zmap_blocks; i++) {
	85	struct buffer_head *bh = sbi->s_zmap[i];
	86	int j;
	87
	88	lock_kernel();
	89	if ((j = minix_find_first_zero_bit(bh->b_data, 8192)) < 8192) {
	90	minix_set_bit(j,bh->b_data);
	91	unlock_kernel();
	92	mark_buffer_dirty(bh);
	93	j += i*8192 + sbi->s_firstdatazone-1;
	94	if (j < sbi->s_firstdatazone \|\| j >= sbi->s_nzones)
	95	break;
	96	return j;
	97	}
	98	unlock_kernel();
	99	}
	100	return 0;
	101	}
	102
	103	unsigned long minix_count_free_blocks(struct minix_sb_info *sbi)
	104	{
	105	return (count_free(sbi->s_zmap, sbi->s_zmap_blocks,
	106	sbi->s_nzones - sbi->s_firstdatazone + 1)
	107	<< sbi->s_log_zone_size);
	108	}
	109
	110	struct minix_inode *
	111	minix_V1_raw_inode(struct super_block sb, ino_t ino, struct buffer_head *bh)
	112	{
	113	int block;
	114	struct minix_sb_info *sbi = minix_sb(sb);
	115	struct minix_inode *p;
	116
	117	if (!ino \|\| ino > sbi->s_ninodes) {
	118	printk("Bad inode number on dev %s: %ld is out of range\n",
	119	sb->s_id, (long)ino);
	120	return NULL;
	121	}
	122	ino--;
	123	block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
124	ino / MINIX_INODES_PER_BLOCK;
125	*bh = sb_bread(sb, block);
126	if (!*bh) {
11b84487	127	printk("Unable to read inode block\n");
1da177e4 LT	128	return NULL;
	129	}
	130	p = (void )(bh)->b_data;
	131	return p + ino % MINIX_INODES_PER_BLOCK;
	132	}
	133
	134	struct minix2_inode *
	135	minix_V2_raw_inode(struct super_block sb, ino_t ino, struct buffer_head *bh)
	136	{
	137	int block;
	138	struct minix_sb_info *sbi = minix_sb(sb);
	139	struct minix2_inode *p;
	140
	141	*bh = NULL;
	142	if (!ino \|\| ino > sbi->s_ninodes) {
	143	printk("Bad inode number on dev %s: %ld is out of range\n",
	144	sb->s_id, (long)ino);
	145	return NULL;
	146	}
	147	ino--;
	148	block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
	149	ino / MINIX2_INODES_PER_BLOCK;
	150	*bh = sb_bread(sb, block);
	151	if (!*bh) {
11b84487	152	printk("Unable to read inode block\n");
1da177e4 LT	153	return NULL;
	154	}
	155	p = (void )(bh)->b_data;
	156	return p + ino % MINIX2_INODES_PER_BLOCK;
	157	}
	158
	159	/* Clear the link count and mode of a deleted inode on disk. */
	160
	161	static void minix_clear_inode(struct inode *inode)
	162	{
	163	struct buffer_head *bh = NULL;
	164
	165	if (INODE_VERSION(inode) == MINIX_V1) {
	166	struct minix_inode *raw_inode;
	167	raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
	168	if (raw_inode) {
	169	raw_inode->i_nlinks = 0;
	170	raw_inode->i_mode = 0;
	171	}
	172	} else {
	173	struct minix2_inode *raw_inode;
	174	raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
	175	if (raw_inode) {
	176	raw_inode->i_nlinks = 0;
	177	raw_inode->i_mode = 0;
	178	}
	179	}
	180	if (bh) {
	181	mark_buffer_dirty(bh);
	182	brelse (bh);
	183	}
	184	}
	185
	186	void minix_free_inode(struct inode * inode)
	187	{
	188	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
	189	struct buffer_head * bh;
	190	unsigned long ino;
	191
	192	ino = inode->i_ino;
	193	if (ino < 1 \|\| ino > sbi->s_ninodes) {
	194	printk("minix_free_inode: inode 0 or nonexistent inode\n");
	195	goto out;
	196	}
	197	if ((ino >> 13) >= sbi->s_imap_blocks) {
	198	printk("minix_free_inode: nonexistent imap in superblock\n");
	199	goto out;
	200	}
	201
	202	minix_clear_inode(inode); /* clear on-disk copy */
	203
	204	bh = sbi->s_imap[ino >> 13];
	205	lock_kernel();
	206	if (!minix_test_and_clear_bit(ino & 8191, bh->b_data))
11b84487	207	printk("minix_free_inode: bit %lu already cleared\n", ino);
1da177e4 LT	208	unlock_kernel();
	209	mark_buffer_dirty(bh);
	210	out:
	211	clear_inode(inode); /* clear in-memory copy */
	212	}
	213
	214	struct inode * minix_new_inode(const struct inode * dir, int * error)
	215	{
	216	struct super_block *sb = dir->i_sb;
	217	struct minix_sb_info *sbi = minix_sb(sb);
	218	struct inode *inode = new_inode(sb);
	219	struct buffer_head * bh;
	220	int i,j;
	221
	222	if (!inode) {
	223	*error = -ENOMEM;
	224	return NULL;
	225	}
	226	j = 8192;
	227	bh = NULL;
	228	*error = -ENOSPC;
	229	lock_kernel();
	230	for (i = 0; i < sbi->s_imap_blocks; i++) {
	231	bh = sbi->s_imap[i];
	232	if ((j = minix_find_first_zero_bit(bh->b_data, 8192)) < 8192)
	233	break;
	234	}
	235	if (!bh \|\| j >= 8192) {
	236	unlock_kernel();
	237	iput(inode);
	238	return NULL;
	239	}
	240	if (minix_test_and_set_bit(j,bh->b_data)) { /* shouldn't happen */
11b84487	241	printk("new_inode: bit already set\n");
1da177e4 LT	242	unlock_kernel();
	243	iput(inode);
	244	return NULL;
	245	}
	246	unlock_kernel();
	247	mark_buffer_dirty(bh);
	248	j += i*8192;
	249	if (!j \|\| j > sbi->s_ninodes) {
	250	iput(inode);
	251	return NULL;
	252	}
	253	inode->i_uid = current->fsuid;
	254	inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
	255	inode->i_ino = j;
	256	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
ba52de12	257	inode->i_blocks = 0;
1da177e4 LT	258	memset(&minix_i(inode)->u, 0, sizeof(minix_i(inode)->u));
	259	insert_inode_hash(inode);
	260	mark_inode_dirty(inode);
	261
	262	*error = 0;
	263	return inode;
	264	}
	265
	266	unsigned long minix_count_free_inodes(struct minix_sb_info *sbi)
	267	{
	268	return count_free(sbi->s_imap, sbi->s_imap_blocks, sbi->s_ninodes + 1);
	269	}