[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/smp_lock.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;
	unsigned int offset;
	int block;

	lock_kernel();

	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);
		unlock_kernel();
		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);
					unlock_kernel();
					return 0;
				}
			}
			offset += BFS_DIRENT_SIZE;
			f->f_pos += BFS_DIRENT_SIZE;
		} while ((offset < BFS_BSIZE) && (f->f_pos < dir->i_size));
		brelse(bh);
	}

	unlock_kernel();
	return 0;	
}

const struct file_operations bfs_dir_operations = {
	.read		= generic_read_dir,
	.readdir	= bfs_readdir,
	.fsync		= file_fsync,
};

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;
	lock_kernel();
	ino = find_first_zero_bit(info->si_imap, info->si_lasti);
	if (ino > info->si_lasti) {
		unlock_kernel();
		iput(inode);
		return -ENOSPC;
	}
	set_bit(ino, info->si_imap);
	info->si_freei--;
	inode->i_uid = current->fsuid;
	inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
	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_mode = mode;
	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);
		iput(inode);
		unlock_kernel();
		return err;
	}
	unlock_kernel();
	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;

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

	lock_kernel();
	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)) {
			unlock_kernel();
			return ERR_CAST(inode);
		}
	}
	unlock_kernel();
	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;
	int err;

	lock_kernel();
	err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
							inode->i_ino);
	if (err) {
		unlock_kernel();
		return err;
	}
	inc_nlink(inode);
	inode->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(inode);
	atomic_inc(&inode->i_count);
	d_instantiate(new, inode);
	unlock_kernel();
	return 0;
}

static int bfs_unlink(struct inode *dir, struct dentry *dentry)
{
	int error = -ENOENT;
	struct inode *inode;
	struct buffer_head *bh;
	struct bfs_dirent *de;

	inode = dentry->d_inode;
	lock_kernel();
	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);
		inode->i_nlink = 1;
	}
	de->ino = 0;
	mark_buffer_dirty(bh);
	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);
	unlock_kernel();
	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;
	int error = -ENOENT;

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

	lock_kernel();
	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(old_bh);
	error = 0;

end_rename:
	unlock_kernel();
	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(bh);
				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>
	11	#include <linux/smp_lock.h>
	12	#include <linux/buffer_head.h>
	13	#include <linux/sched.h>
	14	#include "bfs.h"
	15
	16	#undef DEBUG
	17
	18	#ifdef DEBUG
	19	#define dprintf(x...) printf(x)
	20	#else
	21	#define dprintf(x...)
	22	#endif
	23
f433dc56 DV	24	static int bfs_add_entry(struct inode dir, const unsigned char name,
	25	int namelen, int ino);
	26	static struct buffer_head bfs_find_entry(struct inode dir,
	27	const unsigned char *name, int namelen,
	28	struct bfs_dirent **res_dir);
1da177e4	29
f433dc56	30	static int bfs_readdir(struct file f, void dirent, filldir_t filldir)
1da177e4	31	{
f433dc56 DV	32	struct inode *dir = f->f_path.dentry->d_inode;
	33	struct buffer_head *bh;
	34	struct bfs_dirent *de;
1da177e4 LT	35	unsigned int offset;
	36	int block;
	37
	38	lock_kernel();
	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);
1da177e4 LT	44	unlock_kernel();
	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 LT	63	brelse(bh);
	64	unlock_kernel();
	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
	74	unlock_kernel();
	75	return 0;
	76	}
	77
4b6f5d20	78	const struct file_operations bfs_dir_operations = {
1da177e4 LT	79	.read = generic_read_dir,
	80	.readdir = bfs_readdir,
	81	.fsync = file_fsync,
	82	};
	83
	84	extern void dump_imap(const char , struct super_block );
	85
f433dc56 DV	86	static int bfs_create(struct inode dir, struct dentry dentry, int mode,
f433dc56 DV	87	struct nameidata *nd)
1da177e4 LT	88	{
1da177e4 LT	89	int err;
f433dc56 DV	90	struct inode *inode;
	91	struct super_block *s = dir->i_sb;
	92	struct bfs_sb_info *info = BFS_SB(s);
1da177e4 LT	93	unsigned long ino;
	94
	95	inode = new_inode(s);
	96	if (!inode)
	97	return -ENOSPC;
	98	lock_kernel();
	99	ino = find_first_zero_bit(info->si_imap, info->si_lasti);
	100	if (ino > info->si_lasti) {
	101	unlock_kernel();
	102	iput(inode);
	103	return -ENOSPC;
	104	}
f433dc56	105	set_bit(ino, info->si_imap);
1da177e4 LT	106	info->si_freei--;
	107	inode->i_uid = current->fsuid;
	108	inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
	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;
	114	inode->i_mode = mode;
	115	inode->i_ino = ino;
ce0fe7e7	116	BFS_I(inode)->i_dsk_ino = ino;
1da177e4 LT	117	BFS_I(inode)->i_sblock = 0;
	118	BFS_I(inode)->i_eblock = 0;
	119	insert_inode_hash(inode);
	120	mark_inode_dirty(inode);
f433dc56	121	dump_imap("create", s);
1da177e4	122
f433dc56 DV	123	err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
f433dc56 DV	124	inode->i_ino);
1da177e4	125	if (err) {
9a53c3a7	126	inode_dec_link_count(inode);
1da177e4 LT	127	iput(inode);
	128	unlock_kernel();
	129	return err;
	130	}
	131	unlock_kernel();
	132	d_instantiate(dentry, inode);
	133	return 0;
	134	}
	135
f433dc56 DV	136	static struct dentry bfs_lookup(struct inode dir, struct dentry *dentry,
f433dc56 DV	137	struct nameidata *nd)
1da177e4	138	{
f433dc56 DV	139	struct inode *inode = NULL;
	140	struct buffer_head *bh;
	141	struct bfs_dirent *de;
1da177e4 LT	142
	143	if (dentry->d_name.len > BFS_NAMELEN)
	144	return ERR_PTR(-ENAMETOOLONG);
	145
	146	lock_kernel();
	147	bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
	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)) {
1da177e4	153	unlock_kernel();
e33ab086	154	return ERR_CAST(inode);
1da177e4 LT	155	}
	156	}
	157	unlock_kernel();
	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;
1da177e4 LT	166	int err;
	167
	168	lock_kernel();
f433dc56 DV	169	err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
f433dc56 DV	170	inode->i_ino);
1da177e4 LT	171	if (err) {
	172	unlock_kernel();
	173	return err;
	174	}
d8c76e6f	175	inc_nlink(inode);
1da177e4 LT	176	inode->i_ctime = CURRENT_TIME_SEC;
	177	mark_inode_dirty(inode);
	178	atomic_inc(&inode->i_count);
	179	d_instantiate(new, inode);
	180	unlock_kernel();
	181	return 0;
	182	}
	183
f433dc56	184	static int bfs_unlink(struct inode dir, struct dentry dentry)
1da177e4 LT	185	{
1da177e4 LT	186	int error = -ENOENT;
f433dc56 DV	187	struct inode *inode;
	188	struct buffer_head *bh;
	189	struct bfs_dirent *de;
1da177e4 LT	190
	191	inode = dentry->d_inode;
	192	lock_kernel();
	193	bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
f433dc56	194	if (!bh \|\| (le16_to_cpu(de->ino) != inode->i_ino))
1da177e4 LT	195	goto out_brelse;
	196
	197	if (!inode->i_nlink) {
f433dc56 DV	198	printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
	199	inode->i_sb->s_id, inode->i_ino,
	200	inode->i_nlink);
1da177e4 LT	201	inode->i_nlink = 1;
	202	}
	203	de->ino = 0;
	204	mark_buffer_dirty(bh);
	205	dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
	206	mark_inode_dirty(dir);
1da177e4	207	inode->i_ctime = dir->i_ctime;
9a53c3a7	208	inode_dec_link_count(inode);
1da177e4 LT	209	error = 0;
	210
	211	out_brelse:
	212	brelse(bh);
	213	unlock_kernel();
	214	return error;
	215	}
	216
f433dc56 DV	217	static int bfs_rename(struct inode old_dir, struct dentry old_dentry,
f433dc56 DV	218	struct inode new_dir, struct dentry new_dentry)
1da177e4	219	{
f433dc56 DV	220	struct inode old_inode, new_inode;
	221	struct buffer_head old_bh, new_bh;
	222	struct bfs_dirent old_de, new_de;
1da177e4 LT	223	int error = -ENOENT;
	224
	225	old_bh = new_bh = NULL;
	226	old_inode = old_dentry->d_inode;
	227	if (S_ISDIR(old_inode->i_mode))
	228	return -EINVAL;
	229
	230	lock_kernel();
	231	old_bh = bfs_find_entry(old_dir,
	232	old_dentry->d_name.name,
	233	old_dentry->d_name.len, &old_de);
	234
f433dc56	235	if (!old_bh \|\| (le16_to_cpu(old_de->ino) != old_inode->i_ino))
1da177e4 LT	236	goto end_rename;
	237
	238	error = -EPERM;
	239	new_inode = new_dentry->d_inode;
	240	new_bh = bfs_find_entry(new_dir,
	241	new_dentry->d_name.name,
	242	new_dentry->d_name.len, &new_de);
	243
	244	if (new_bh && !new_inode) {
	245	brelse(new_bh);
	246	new_bh = NULL;
	247	}
	248	if (!new_bh) {
	249	error = bfs_add_entry(new_dir,
	250	new_dentry->d_name.name,
f433dc56 DV	251	new_dentry->d_name.len,
f433dc56 DV	252	old_inode->i_ino);
1da177e4 LT	253	if (error)
	254	goto end_rename;
	255	}
	256	old_de->ino = 0;
	257	old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
	258	mark_inode_dirty(old_dir);
	259	if (new_inode) {
1da177e4	260	new_inode->i_ctime = CURRENT_TIME_SEC;
9a53c3a7	261	inode_dec_link_count(new_inode);
1da177e4 LT	262	}
	263	mark_buffer_dirty(old_bh);
	264	error = 0;
	265
	266	end_rename:
	267	unlock_kernel();
	268	brelse(old_bh);
	269	brelse(new_bh);
	270	return error;
	271	}
	272
754661f1	273	const struct inode_operations bfs_dir_inops = {
1da177e4 LT	274	.create = bfs_create,
	275	.lookup = bfs_lookup,
	276	.link = bfs_link,
	277	.unlink = bfs_unlink,
	278	.rename = bfs_rename,
	279	};
	280
f433dc56 DV	281	static int bfs_add_entry(struct inode dir, const unsigned char name,
f433dc56 DV	282	int namelen, int ino)
1da177e4	283	{
f433dc56 DV	284	struct buffer_head *bh;
	285	struct bfs_dirent *de;
	286	int block, sblock, eblock, off, pos;
1da177e4 LT	287	int i;
	288
	289	dprintf("name=%s, namelen=%d\n", name, namelen);
	290
	291	if (!namelen)
	292	return -ENOENT;
	293	if (namelen > BFS_NAMELEN)
	294	return -ENAMETOOLONG;
	295
	296	sblock = BFS_I(dir)->i_sblock;
	297	eblock = BFS_I(dir)->i_eblock;
f433dc56	298	for (block = sblock; block <= eblock; block++) {
1da177e4	299	bh = sb_bread(dir->i_sb, block);
f433dc56	300	if (!bh)
1da177e4	301	return -ENOSPC;
f433dc56	302	for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
1da177e4	303	de = (struct bfs_dirent *)(bh->b_data + off);
1da177e4	304	if (!de->ino) {
f433dc56 DV	305	pos = (block - sblock) * BFS_BSIZE + off;
f433dc56 DV	306	if (pos >= dir->i_size) {
1da177e4 LT	307	dir->i_size += BFS_DIRENT_SIZE;
	308	dir->i_ctime = CURRENT_TIME_SEC;
	309	}
	310	dir->i_mtime = CURRENT_TIME_SEC;
	311	mark_inode_dirty(dir);
fac92bec	312	de->ino = cpu_to_le16((u16)ino);
f433dc56 DV	313	for (i = 0; i < BFS_NAMELEN; i++)
	314	de->name[i] =
	315	(i < namelen) ? name[i] : 0;
1da177e4 LT	316	mark_buffer_dirty(bh);
	317	brelse(bh);
	318	return 0;
	319	}
	320	}
	321	brelse(bh);
	322	}
	323	return -ENOSPC;
	324	}
	325
f433dc56 DV	326	static inline int bfs_namecmp(int len, const unsigned char *name,
f433dc56 DV	327	const char *buffer)
1da177e4	328	{
f433dc56	329	if ((len < BFS_NAMELEN) && buffer[len])
1da177e4 LT	330	return 0;
	331	return !memcmp(name, buffer, len);
	332	}
	333
f433dc56 DV	334	static struct buffer_head bfs_find_entry(struct inode dir,
	335	const unsigned char *name, int namelen,
	336	struct bfs_dirent **res_dir)
1da177e4	337	{
f433dc56 DV	338	unsigned long block = 0, offset = 0;
	339	struct buffer_head *bh = NULL;
	340	struct bfs_dirent *de;
1da177e4 LT	341
	342	*res_dir = NULL;
	343	if (namelen > BFS_NAMELEN)
	344	return NULL;
f433dc56	345
1da177e4 LT	346	while (block * BFS_BSIZE + offset < dir->i_size) {
	347	if (!bh) {
	348	bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
	349	if (!bh) {
	350	block++;
	351	continue;
	352	}
	353	}
	354	de = (struct bfs_dirent *)(bh->b_data + offset);
	355	offset += BFS_DIRENT_SIZE;
f433dc56 DV	356	if (le16_to_cpu(de->ino) &&
f433dc56 DV	357	bfs_namecmp(namelen, name, de->name)) {
1da177e4 LT	358	*res_dir = de;
	359	return bh;
	360	}
	361	if (offset < bh->b_size)
	362	continue;
	363	brelse(bh);
	364	bh = NULL;
	365	offset = 0;
	366	block++;
	367	}
	368	brelse(bh);
	369	return NULL;
	370	}