[linux.git] / fs / bfs / dir.c

/*
 *	fs/bfs/dir.c
 *	BFS directory operations.
 *	Copyright (C) 1999,2000  Tigran Aivazian <[email protected]>
 *      Made endianness-clean by Andrew Stribblehill <[email protected]> 2005
 */

#include <linux/time.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/sched.h>
#include "bfs.h"

#undef DEBUG

#ifdef DEBUG
#define dprintf(x...)	printf(x)
#else
#define dprintf(x...)
#endif

static int bfs_add_entry(struct inode *dir, const unsigned char *name,
						int namelen, int ino);
static struct buffer_head *bfs_find_entry(struct inode *dir,
				const unsigned char *name, int namelen,
				struct bfs_dirent **res_dir);

static int bfs_readdir(struct file *f, void *dirent, filldir_t filldir)
{
	struct inode *dir = f->f_path.dentry->d_inode;
	struct buffer_head *bh;
	struct bfs_dirent *de;
	struct bfs_sb_info *info = BFS_SB(dir->i_sb);
	unsigned int offset;
	int block;

	mutex_lock(&info->bfs_lock);

	if (f->f_pos & (BFS_DIRENT_SIZE - 1)) {
		printf("Bad f_pos=%08lx for %s:%08lx\n",
					(unsigned long)f->f_pos,
					dir->i_sb->s_id, dir->i_ino);
		mutex_unlock(&info->bfs_lock);
		return -EBADF;
	}

	while (f->f_pos < dir->i_size) {
		offset = f->f_pos & (BFS_BSIZE - 1);
		block = BFS_I(dir)->i_sblock + (f->f_pos >> BFS_BSIZE_BITS);
		bh = sb_bread(dir->i_sb, block);
		if (!bh) {
			f->f_pos += BFS_BSIZE - offset;
			continue;
		}
		do {
			de = (struct bfs_dirent *)(bh->b_data + offset);
			if (de->ino) {
				int size = strnlen(de->name, BFS_NAMELEN);
				if (filldir(dirent, de->name, size, f->f_pos,
						le16_to_cpu(de->ino),
						DT_UNKNOWN) < 0) {
					brelse(bh);
					mutex_unlock(&info->bfs_lock);
					return 0;
				}
			}
			offset += BFS_DIRENT_SIZE;
			f->f_pos += BFS_DIRENT_SIZE;
		} while ((offset < BFS_BSIZE) && (f->f_pos < dir->i_size));
		brelse(bh);
	}

	mutex_unlock(&info->bfs_lock);
	return 0;	
}

const struct file_operations bfs_dir_operations = {
	.read		= generic_read_dir,
	.readdir	= bfs_readdir,
	.fsync		= generic_file_fsync,
	.llseek		= generic_file_llseek,
};

extern void dump_imap(const char *, struct super_block *);

static int bfs_create(struct inode *dir, struct dentry *dentry, int mode,
						struct nameidata *nd)
{
	int err;
	struct inode *inode;
	struct super_block *s = dir->i_sb;
	struct bfs_sb_info *info = BFS_SB(s);
	unsigned long ino;

	inode = new_inode(s);
	if (!inode)
		return -ENOSPC;
	mutex_lock(&info->bfs_lock);
	ino = find_first_zero_bit(info->si_imap, info->si_lasti + 1);
	if (ino > info->si_lasti) {
		mutex_unlock(&info->bfs_lock);
		iput(inode);
		return -ENOSPC;
	}
	set_bit(ino, info->si_imap);
	info->si_freei--;
	inode_init_owner(inode, dir, mode);
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
	inode->i_blocks = 0;
	inode->i_op = &bfs_file_inops;
	inode->i_fop = &bfs_file_operations;
	inode->i_mapping->a_ops = &bfs_aops;
	inode->i_ino = ino;
	BFS_I(inode)->i_dsk_ino = ino;
	BFS_I(inode)->i_sblock = 0;
	BFS_I(inode)->i_eblock = 0;
	insert_inode_hash(inode);
        mark_inode_dirty(inode);
	dump_imap("create", s);

	err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
							inode->i_ino);
	if (err) {
		inode_dec_link_count(inode);
		mutex_unlock(&info->bfs_lock);
		iput(inode);
		return err;
	}
	mutex_unlock(&info->bfs_lock);
	d_instantiate(dentry, inode);
	return 0;
}

static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry,
						struct nameidata *nd)
{
	struct inode *inode = NULL;
	struct buffer_head *bh;
	struct bfs_dirent *de;
	struct bfs_sb_info *info = BFS_SB(dir->i_sb);

	if (dentry->d_name.len > BFS_NAMELEN)
		return ERR_PTR(-ENAMETOOLONG);

	mutex_lock(&info->bfs_lock);
	bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
	if (bh) {
		unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
		brelse(bh);
		inode = bfs_iget(dir->i_sb, ino);
		if (IS_ERR(inode)) {
			mutex_unlock(&info->bfs_lock);
			return ERR_CAST(inode);
		}
	}
	mutex_unlock(&info->bfs_lock);
	d_add(dentry, inode);
	return NULL;
}

static int bfs_link(struct dentry *old, struct inode *dir,
						struct dentry *new)
{
	struct inode *inode = old->d_inode;
	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
	int err;

	mutex_lock(&info->bfs_lock);
	err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
							inode->i_ino);
	if (err) {
		mutex_unlock(&info->bfs_lock);
		return err;
	}
	inc_nlink(inode);
	inode->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(inode);
	ihold(inode);
	d_instantiate(new, inode);
	mutex_unlock(&info->bfs_lock);
	return 0;
}

static int bfs_unlink(struct inode *dir, struct dentry *dentry)
{
	int error = -ENOENT;
	struct inode *inode = dentry->d_inode;
	struct buffer_head *bh;
	struct bfs_dirent *de;
	struct bfs_sb_info *info = BFS_SB(inode->i_sb);

	mutex_lock(&info->bfs_lock);
	bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
	if (!bh || (le16_to_cpu(de->ino) != inode->i_ino))
		goto out_brelse;

	if (!inode->i_nlink) {
		printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
					inode->i_sb->s_id, inode->i_ino,
					inode->i_nlink);
		set_nlink(inode, 1);
	}
	de->ino = 0;
	mark_buffer_dirty_inode(bh, dir);
	dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
	mark_inode_dirty(dir);
	inode->i_ctime = dir->i_ctime;
	inode_dec_link_count(inode);
	error = 0;

out_brelse:
	brelse(bh);
	mutex_unlock(&info->bfs_lock);
	return error;
}

static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
			struct inode *new_dir, struct dentry *new_dentry)
{
	struct inode *old_inode, *new_inode;
	struct buffer_head *old_bh, *new_bh;
	struct bfs_dirent *old_de, *new_de;
	struct bfs_sb_info *info;
	int error = -ENOENT;

	old_bh = new_bh = NULL;
	old_inode = old_dentry->d_inode;
	if (S_ISDIR(old_inode->i_mode))
		return -EINVAL;

	info = BFS_SB(old_inode->i_sb);

	mutex_lock(&info->bfs_lock);
	old_bh = bfs_find_entry(old_dir, 
				old_dentry->d_name.name, 
				old_dentry->d_name.len, &old_de);

	if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino))
		goto end_rename;

	error = -EPERM;
	new_inode = new_dentry->d_inode;
	new_bh = bfs_find_entry(new_dir, 
				new_dentry->d_name.name, 
				new_dentry->d_name.len, &new_de);

	if (new_bh && !new_inode) {
		brelse(new_bh);
		new_bh = NULL;
	}
	if (!new_bh) {
		error = bfs_add_entry(new_dir, 
					new_dentry->d_name.name,
					new_dentry->d_name.len,
					old_inode->i_ino);
		if (error)
			goto end_rename;
	}
	old_de->ino = 0;
	old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
	mark_inode_dirty(old_dir);
	if (new_inode) {
		new_inode->i_ctime = CURRENT_TIME_SEC;
		inode_dec_link_count(new_inode);
	}
	mark_buffer_dirty_inode(old_bh, old_dir);
	error = 0;

end_rename:
	mutex_unlock(&info->bfs_lock);
	brelse(old_bh);
	brelse(new_bh);
	return error;
}

const struct inode_operations bfs_dir_inops = {
	.create			= bfs_create,
	.lookup			= bfs_lookup,
	.link			= bfs_link,
	.unlink			= bfs_unlink,
	.rename			= bfs_rename,
};

static int bfs_add_entry(struct inode *dir, const unsigned char *name,
							int namelen, int ino)
{
	struct buffer_head *bh;
	struct bfs_dirent *de;
	int block, sblock, eblock, off, pos;
	int i;

	dprintf("name=%s, namelen=%d\n", name, namelen);

	if (!namelen)
		return -ENOENT;
	if (namelen > BFS_NAMELEN)
		return -ENAMETOOLONG;

	sblock = BFS_I(dir)->i_sblock;
	eblock = BFS_I(dir)->i_eblock;
	for (block = sblock; block <= eblock; block++) {
		bh = sb_bread(dir->i_sb, block);
		if (!bh)
			return -ENOSPC;
		for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
			de = (struct bfs_dirent *)(bh->b_data + off);
			if (!de->ino) {
				pos = (block - sblock) * BFS_BSIZE + off;
				if (pos >= dir->i_size) {
					dir->i_size += BFS_DIRENT_SIZE;
					dir->i_ctime = CURRENT_TIME_SEC;
				}
				dir->i_mtime = CURRENT_TIME_SEC;
				mark_inode_dirty(dir);
				de->ino = cpu_to_le16((u16)ino);
				for (i = 0; i < BFS_NAMELEN; i++)
					de->name[i] =
						(i < namelen) ? name[i] : 0;
				mark_buffer_dirty_inode(bh, dir);
				brelse(bh);
				return 0;
			}
		}
		brelse(bh);
	}
	return -ENOSPC;
}

static inline int bfs_namecmp(int len, const unsigned char *name,
							const char *buffer)
{
	if ((len < BFS_NAMELEN) && buffer[len])
		return 0;
	return !memcmp(name, buffer, len);
}

static struct buffer_head *bfs_find_entry(struct inode *dir,
			const unsigned char *name, int namelen,
			struct bfs_dirent **res_dir)
{
	unsigned long block = 0, offset = 0;
	struct buffer_head *bh = NULL;
	struct bfs_dirent *de;

	*res_dir = NULL;
	if (namelen > BFS_NAMELEN)
		return NULL;

	while (block * BFS_BSIZE + offset < dir->i_size) {
		if (!bh) {
			bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
			if (!bh) {
				block++;
				continue;
			}
		}
		de = (struct bfs_dirent *)(bh->b_data + offset);
		offset += BFS_DIRENT_SIZE;
		if (le16_to_cpu(de->ino) &&
				bfs_namecmp(namelen, name, de->name)) {
			*res_dir = de;
			return bh;
		}
		if (offset < bh->b_size)
			continue;
		brelse(bh);
		bh = NULL;
		offset = 0;
		block++;
	}
	brelse(bh);
	return NULL;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* fs/bfs/dir.c
	3	* BFS directory operations.
	4	* Copyright (C) 1999,2000 Tigran Aivazian <[email protected]>
fac92bec	5	* Made endianness-clean by Andrew Stribblehill <[email protected]> 2005
1da177e4 LT	6	*/
	7
	8	#include <linux/time.h>
	9	#include <linux/string.h>
	10	#include <linux/fs.h>
1da177e4 LT	11	#include <linux/buffer_head.h>
	12	#include <linux/sched.h>
	13	#include "bfs.h"
	14
	15	#undef DEBUG
	16
	17	#ifdef DEBUG
	18	#define dprintf(x...) printf(x)
	19	#else
	20	#define dprintf(x...)
	21	#endif
	22
f433dc56 DV	23	static int bfs_add_entry(struct inode dir, const unsigned char name,
	24	int namelen, int ino);
	25	static struct buffer_head bfs_find_entry(struct inode dir,
	26	const unsigned char *name, int namelen,
	27	struct bfs_dirent **res_dir);
1da177e4	28
f433dc56	29	static int bfs_readdir(struct file f, void dirent, filldir_t filldir)
1da177e4	30	{
f433dc56 DV	31	struct inode *dir = f->f_path.dentry->d_inode;
	32	struct buffer_head *bh;
	33	struct bfs_dirent *de;
3f165e4c	34	struct bfs_sb_info *info = BFS_SB(dir->i_sb);
1da177e4 LT	35	unsigned int offset;
	36	int block;
	37
3f165e4c	38	mutex_lock(&info->bfs_lock);
1da177e4	39
f433dc56 DV	40	if (f->f_pos & (BFS_DIRENT_SIZE - 1)) {
	41	printf("Bad f_pos=%08lx for %s:%08lx\n",
	42	(unsigned long)f->f_pos,
	43	dir->i_sb->s_id, dir->i_ino);
3f165e4c	44	mutex_unlock(&info->bfs_lock);
1da177e4 LT	45	return -EBADF;
	46	}
	47
	48	while (f->f_pos < dir->i_size) {
f433dc56	49	offset = f->f_pos & (BFS_BSIZE - 1);
1da177e4 LT	50	block = BFS_I(dir)->i_sblock + (f->f_pos >> BFS_BSIZE_BITS);
	51	bh = sb_bread(dir->i_sb, block);
	52	if (!bh) {
	53	f->f_pos += BFS_BSIZE - offset;
	54	continue;
	55	}
	56	do {
	57	de = (struct bfs_dirent *)(bh->b_data + offset);
	58	if (de->ino) {
	59	int size = strnlen(de->name, BFS_NAMELEN);
f433dc56 DV	60	if (filldir(dirent, de->name, size, f->f_pos,
	61	le16_to_cpu(de->ino),
	62	DT_UNKNOWN) < 0) {
1da177e4	63	brelse(bh);
3f165e4c	64	mutex_unlock(&info->bfs_lock);
1da177e4 LT	65	return 0;
	66	}
	67	}
	68	offset += BFS_DIRENT_SIZE;
	69	f->f_pos += BFS_DIRENT_SIZE;
f433dc56	70	} while ((offset < BFS_BSIZE) && (f->f_pos < dir->i_size));
1da177e4 LT	71	brelse(bh);
	72	}
	73
3f165e4c	74	mutex_unlock(&info->bfs_lock);
1da177e4 LT	75	return 0;
	76	}
	77
4b6f5d20	78	const struct file_operations bfs_dir_operations = {
1da177e4 LT	79	.read = generic_read_dir,
1da177e4 LT	80	.readdir = bfs_readdir,
1b061d92	81	.fsync = generic_file_fsync,
3222a3e5	82	.llseek = generic_file_llseek,
1da177e4 LT	83	};
	84
	85	extern void dump_imap(const char , struct super_block );
	86
f433dc56 DV	87	static int bfs_create(struct inode dir, struct dentry dentry, int mode,
f433dc56 DV	88	struct nameidata *nd)
1da177e4 LT	89	{
1da177e4 LT	90	int err;
f433dc56 DV	91	struct inode *inode;
	92	struct super_block *s = dir->i_sb;
	93	struct bfs_sb_info *info = BFS_SB(s);
1da177e4 LT	94	unsigned long ino;
	95
	96	inode = new_inode(s);
	97	if (!inode)
	98	return -ENOSPC;
3f165e4c	99	mutex_lock(&info->bfs_lock);
69b195be	100	ino = find_first_zero_bit(info->si_imap, info->si_lasti + 1);
1da177e4	101	if (ino > info->si_lasti) {
3f165e4c	102	mutex_unlock(&info->bfs_lock);
1da177e4 LT	103	iput(inode);
	104	return -ENOSPC;
	105	}
f433dc56	106	set_bit(ino, info->si_imap);
1da177e4	107	info->si_freei--;
e6ecdc70	108	inode_init_owner(inode, dir, mode);
1da177e4	109	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
ba52de12	110	inode->i_blocks = 0;
1da177e4 LT	111	inode->i_op = &bfs_file_inops;
	112	inode->i_fop = &bfs_file_operations;
	113	inode->i_mapping->a_ops = &bfs_aops;
1da177e4	114	inode->i_ino = ino;
ce0fe7e7	115	BFS_I(inode)->i_dsk_ino = ino;
1da177e4 LT	116	BFS_I(inode)->i_sblock = 0;
	117	BFS_I(inode)->i_eblock = 0;
	118	insert_inode_hash(inode);
	119	mark_inode_dirty(inode);
f433dc56	120	dump_imap("create", s);
1da177e4	121
f433dc56 DV	122	err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
f433dc56 DV	123	inode->i_ino);
1da177e4	124	if (err) {
9a53c3a7	125	inode_dec_link_count(inode);
3f165e4c	126	mutex_unlock(&info->bfs_lock);
1558182f	127	iput(inode);
1da177e4 LT	128	return err;
1da177e4 LT	129	}
3f165e4c	130	mutex_unlock(&info->bfs_lock);
1da177e4 LT	131	d_instantiate(dentry, inode);
	132	return 0;
	133	}
	134
f433dc56 DV	135	static struct dentry bfs_lookup(struct inode dir, struct dentry *dentry,
f433dc56 DV	136	struct nameidata *nd)
1da177e4	137	{
f433dc56 DV	138	struct inode *inode = NULL;
	139	struct buffer_head *bh;
	140	struct bfs_dirent *de;
3f165e4c	141	struct bfs_sb_info *info = BFS_SB(dir->i_sb);
1da177e4 LT	142
	143	if (dentry->d_name.len > BFS_NAMELEN)
	144	return ERR_PTR(-ENAMETOOLONG);
	145
3f165e4c	146	mutex_lock(&info->bfs_lock);
1da177e4 LT	147	bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
1da177e4 LT	148	if (bh) {
fac92bec	149	unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
1da177e4	150	brelse(bh);
e33ab086 DH	151	inode = bfs_iget(dir->i_sb, ino);
e33ab086 DH	152	if (IS_ERR(inode)) {
3f165e4c	153	mutex_unlock(&info->bfs_lock);
e33ab086	154	return ERR_CAST(inode);
1da177e4 LT	155	}
1da177e4 LT	156	}
3f165e4c	157	mutex_unlock(&info->bfs_lock);
1da177e4 LT	158	d_add(dentry, inode);
	159	return NULL;
	160	}
	161
f433dc56 DV	162	static int bfs_link(struct dentry old, struct inode dir,
f433dc56 DV	163	struct dentry *new)
1da177e4	164	{
f433dc56	165	struct inode *inode = old->d_inode;
3f165e4c	166	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
1da177e4 LT	167	int err;
1da177e4 LT	168
3f165e4c	169	mutex_lock(&info->bfs_lock);
f433dc56 DV	170	err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
f433dc56 DV	171	inode->i_ino);
1da177e4	172	if (err) {
3f165e4c	173	mutex_unlock(&info->bfs_lock);
1da177e4 LT	174	return err;
1da177e4 LT	175	}
d8c76e6f	176	inc_nlink(inode);
1da177e4 LT	177	inode->i_ctime = CURRENT_TIME_SEC;
1da177e4 LT	178	mark_inode_dirty(inode);
7de9c6ee	179	ihold(inode);
1da177e4	180	d_instantiate(new, inode);
3f165e4c	181	mutex_unlock(&info->bfs_lock);
1da177e4 LT	182	return 0;
	183	}
	184
f433dc56	185	static int bfs_unlink(struct inode dir, struct dentry dentry)
1da177e4 LT	186	{
1da177e4 LT	187	int error = -ENOENT;
3f165e4c	188	struct inode *inode = dentry->d_inode;
f433dc56 DV	189	struct buffer_head *bh;
f433dc56 DV	190	struct bfs_dirent *de;
3f165e4c	191	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
1da177e4	192
3f165e4c	193	mutex_lock(&info->bfs_lock);
1da177e4	194	bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
f433dc56	195	if (!bh \|\| (le16_to_cpu(de->ino) != inode->i_ino))
1da177e4 LT	196	goto out_brelse;
	197
	198	if (!inode->i_nlink) {
f433dc56 DV	199	printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
	200	inode->i_sb->s_id, inode->i_ino,
	201	inode->i_nlink);
bfe86848	202	set_nlink(inode, 1);
1da177e4 LT	203	}
1da177e4 LT	204	de->ino = 0;
4427f0c3	205	mark_buffer_dirty_inode(bh, dir);
1da177e4 LT	206	dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
1da177e4 LT	207	mark_inode_dirty(dir);
1da177e4	208	inode->i_ctime = dir->i_ctime;
9a53c3a7	209	inode_dec_link_count(inode);
1da177e4 LT	210	error = 0;
	211
	212	out_brelse:
	213	brelse(bh);
3f165e4c	214	mutex_unlock(&info->bfs_lock);
1da177e4 LT	215	return error;
	216	}
	217
f433dc56 DV	218	static int bfs_rename(struct inode old_dir, struct dentry old_dentry,
f433dc56 DV	219	struct inode new_dir, struct dentry new_dentry)
1da177e4	220	{
f433dc56 DV	221	struct inode old_inode, new_inode;
	222	struct buffer_head old_bh, new_bh;
	223	struct bfs_dirent old_de, new_de;
3f165e4c	224	struct bfs_sb_info *info;
1da177e4 LT	225	int error = -ENOENT;
	226
	227	old_bh = new_bh = NULL;
	228	old_inode = old_dentry->d_inode;
	229	if (S_ISDIR(old_inode->i_mode))
	230	return -EINVAL;
	231
3f165e4c DV	232	info = BFS_SB(old_inode->i_sb);
	233
	234	mutex_lock(&info->bfs_lock);
1da177e4 LT	235	old_bh = bfs_find_entry(old_dir,
	236	old_dentry->d_name.name,
	237	old_dentry->d_name.len, &old_de);
	238
f433dc56	239	if (!old_bh \|\| (le16_to_cpu(old_de->ino) != old_inode->i_ino))
1da177e4 LT	240	goto end_rename;
	241
	242	error = -EPERM;
	243	new_inode = new_dentry->d_inode;
	244	new_bh = bfs_find_entry(new_dir,
	245	new_dentry->d_name.name,
	246	new_dentry->d_name.len, &new_de);
	247
	248	if (new_bh && !new_inode) {
	249	brelse(new_bh);
	250	new_bh = NULL;
	251	}
	252	if (!new_bh) {
	253	error = bfs_add_entry(new_dir,
	254	new_dentry->d_name.name,
f433dc56 DV	255	new_dentry->d_name.len,
f433dc56 DV	256	old_inode->i_ino);
1da177e4 LT	257	if (error)
	258	goto end_rename;
	259	}
	260	old_de->ino = 0;
	261	old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
	262	mark_inode_dirty(old_dir);
	263	if (new_inode) {
1da177e4	264	new_inode->i_ctime = CURRENT_TIME_SEC;
9a53c3a7	265	inode_dec_link_count(new_inode);
1da177e4	266	}
4427f0c3	267	mark_buffer_dirty_inode(old_bh, old_dir);
1da177e4 LT	268	error = 0;
	269
	270	end_rename:
3f165e4c	271	mutex_unlock(&info->bfs_lock);
1da177e4 LT	272	brelse(old_bh);
	273	brelse(new_bh);
	274	return error;
	275	}
	276
754661f1	277	const struct inode_operations bfs_dir_inops = {
1da177e4 LT	278	.create = bfs_create,
	279	.lookup = bfs_lookup,
	280	.link = bfs_link,
	281	.unlink = bfs_unlink,
	282	.rename = bfs_rename,
	283	};
	284
f433dc56 DV	285	static int bfs_add_entry(struct inode dir, const unsigned char name,
f433dc56 DV	286	int namelen, int ino)
1da177e4	287	{
f433dc56 DV	288	struct buffer_head *bh;
	289	struct bfs_dirent *de;
	290	int block, sblock, eblock, off, pos;
1da177e4 LT	291	int i;
	292
	293	dprintf("name=%s, namelen=%d\n", name, namelen);
	294
	295	if (!namelen)
	296	return -ENOENT;
	297	if (namelen > BFS_NAMELEN)
	298	return -ENAMETOOLONG;
	299
	300	sblock = BFS_I(dir)->i_sblock;
	301	eblock = BFS_I(dir)->i_eblock;
f433dc56	302	for (block = sblock; block <= eblock; block++) {
1da177e4	303	bh = sb_bread(dir->i_sb, block);
f433dc56	304	if (!bh)
1da177e4	305	return -ENOSPC;
f433dc56	306	for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
1da177e4	307	de = (struct bfs_dirent *)(bh->b_data + off);
1da177e4	308	if (!de->ino) {
f433dc56 DV	309	pos = (block - sblock) * BFS_BSIZE + off;
f433dc56 DV	310	if (pos >= dir->i_size) {
1da177e4 LT	311	dir->i_size += BFS_DIRENT_SIZE;
	312	dir->i_ctime = CURRENT_TIME_SEC;
	313	}
	314	dir->i_mtime = CURRENT_TIME_SEC;
	315	mark_inode_dirty(dir);
fac92bec	316	de->ino = cpu_to_le16((u16)ino);
f433dc56 DV	317	for (i = 0; i < BFS_NAMELEN; i++)
	318	de->name[i] =
	319	(i < namelen) ? name[i] : 0;
4427f0c3	320	mark_buffer_dirty_inode(bh, dir);
1da177e4 LT	321	brelse(bh);
	322	return 0;
	323	}
	324	}
	325	brelse(bh);
	326	}
	327	return -ENOSPC;
	328	}
	329
f433dc56 DV	330	static inline int bfs_namecmp(int len, const unsigned char *name,
f433dc56 DV	331	const char *buffer)
1da177e4	332	{
f433dc56	333	if ((len < BFS_NAMELEN) && buffer[len])
1da177e4 LT	334	return 0;
	335	return !memcmp(name, buffer, len);
	336	}
	337
f433dc56 DV	338	static struct buffer_head bfs_find_entry(struct inode dir,
	339	const unsigned char *name, int namelen,
	340	struct bfs_dirent **res_dir)
1da177e4	341	{
f433dc56 DV	342	unsigned long block = 0, offset = 0;
	343	struct buffer_head *bh = NULL;
	344	struct bfs_dirent *de;
1da177e4 LT	345
	346	*res_dir = NULL;
	347	if (namelen > BFS_NAMELEN)
	348	return NULL;
f433dc56	349
1da177e4 LT	350	while (block * BFS_BSIZE + offset < dir->i_size) {
	351	if (!bh) {
	352	bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
	353	if (!bh) {
	354	block++;
	355	continue;
	356	}
	357	}
	358	de = (struct bfs_dirent *)(bh->b_data + offset);
	359	offset += BFS_DIRENT_SIZE;
f433dc56 DV	360	if (le16_to_cpu(de->ino) &&
f433dc56 DV	361	bfs_namecmp(namelen, name, de->name)) {
1da177e4 LT	362	*res_dir = de;
	363	return bh;
	364	}
	365	if (offset < bh->b_size)
	366	continue;
	367	brelse(bh);
	368	bh = NULL;
	369	offset = 0;
	370	block++;
	371	}
	372	brelse(bh);
	373	return NULL;
	374	}