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

// SPDX-License-Identifier: GPL-2.0
/*
 *	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, struct dir_context *ctx)
{
	struct inode *dir = file_inode(f);
	struct buffer_head *bh;
	struct bfs_dirent *de;
	unsigned int offset;
	int block;

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

	while (ctx->pos < dir->i_size) {
		offset = ctx->pos & (BFS_BSIZE - 1);
		block = BFS_I(dir)->i_sblock + (ctx->pos >> BFS_BSIZE_BITS);
		bh = sb_bread(dir->i_sb, block);
		if (!bh) {
			ctx->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 (!dir_emit(ctx, de->name, size,
						le16_to_cpu(de->ino),
						DT_UNKNOWN)) {
					brelse(bh);
					return 0;
				}
			}
			offset += BFS_DIRENT_SIZE;
			ctx->pos += BFS_DIRENT_SIZE;
		} while ((offset < BFS_BSIZE) && (ctx->pos < dir->i_size));
		brelse(bh);
	}
	return 0;
}

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

static int bfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
						bool excl)
{
	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 -ENOMEM;
	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(inode);
	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);
	bfs_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,
						unsigned int flags)
{
	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 = d_inode(old);
	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(inode);
	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 = d_inode(dentry);
	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(dir);
	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,
		      unsigned int flags)
{
	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;

	if (flags & ~RENAME_NOREPLACE)
		return -EINVAL;

	old_bh = new_bh = NULL;
	old_inode = d_inode(old_dentry);
	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 = d_inode(new_dentry);
	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(old_dir);
	mark_inode_dirty(old_dir);
	if (new_inode) {
		new_inode->i_ctime = current_time(new_inode);
		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 -EIO;
		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(dir);
				}
				dir->i_mtime = current_time(dir);
				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
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* fs/bfs/dir.c
	4	* BFS directory operations.
	5	* Copyright (C) 1999,2000 Tigran Aivazian <[email protected]>
fac92bec	6	* Made endianness-clean by Andrew Stribblehill <[email protected]> 2005
1da177e4 LT	7	*/
	8
	9	#include <linux/time.h>
	10	#include <linux/string.h>
	11	#include <linux/fs.h>
1da177e4 LT	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
81b9f66e	30	static int bfs_readdir(struct file f, struct dir_context ctx)
1da177e4	31	{
496ad9aa	32	struct inode *dir = file_inode(f);
f433dc56 DV	33	struct buffer_head *bh;
f433dc56 DV	34	struct bfs_dirent *de;
1da177e4 LT	35	unsigned int offset;
	36	int block;
	37
81b9f66e	38	if (ctx->pos & (BFS_DIRENT_SIZE - 1)) {
f433dc56	39	printf("Bad f_pos=%08lx for %s:%08lx\n",
81b9f66e	40	(unsigned long)ctx->pos,
f433dc56	41	dir->i_sb->s_id, dir->i_ino);
81b9f66e	42	return -EINVAL;
1da177e4 LT	43	}
1da177e4 LT	44
81b9f66e AV	45	while (ctx->pos < dir->i_size) {
	46	offset = ctx->pos & (BFS_BSIZE - 1);
	47	block = BFS_I(dir)->i_sblock + (ctx->pos >> BFS_BSIZE_BITS);
1da177e4 LT	48	bh = sb_bread(dir->i_sb, block);
1da177e4 LT	49	if (!bh) {
81b9f66e	50	ctx->pos += BFS_BSIZE - offset;
1da177e4 LT	51	continue;
	52	}
	53	do {
	54	de = (struct bfs_dirent *)(bh->b_data + offset);
	55	if (de->ino) {
	56	int size = strnlen(de->name, BFS_NAMELEN);
81b9f66e	57	if (!dir_emit(ctx, de->name, size,
f433dc56	58	le16_to_cpu(de->ino),
81b9f66e	59	DT_UNKNOWN)) {
1da177e4	60	brelse(bh);
1da177e4 LT	61	return 0;
	62	}
	63	}
	64	offset += BFS_DIRENT_SIZE;
81b9f66e AV	65	ctx->pos += BFS_DIRENT_SIZE;
81b9f66e AV	66	} while ((offset < BFS_BSIZE) && (ctx->pos < dir->i_size));
1da177e4 LT	67	brelse(bh);
1da177e4 LT	68	}
81b9f66e	69	return 0;
1da177e4 LT	70	}
1da177e4 LT	71
4b6f5d20	72	const struct file_operations bfs_dir_operations = {
1da177e4	73	.read = generic_read_dir,
c51da20c	74	.iterate_shared = bfs_readdir,
1b061d92	75	.fsync = generic_file_fsync,
3222a3e5	76	.llseek = generic_file_llseek,
1da177e4 LT	77	};
1da177e4 LT	78
4acdaf27	79	static int bfs_create(struct inode dir, struct dentry dentry, umode_t mode,
ebfc3b49	80	bool excl)
1da177e4 LT	81	{
1da177e4 LT	82	int err;
f433dc56 DV	83	struct inode *inode;
	84	struct super_block *s = dir->i_sb;
	85	struct bfs_sb_info *info = BFS_SB(s);
1da177e4 LT	86	unsigned long ino;
	87
	88	inode = new_inode(s);
	89	if (!inode)
c3fe5872	90	return -ENOMEM;
3f165e4c	91	mutex_lock(&info->bfs_lock);
69b195be	92	ino = find_first_zero_bit(info->si_imap, info->si_lasti + 1);
1da177e4	93	if (ino > info->si_lasti) {
3f165e4c	94	mutex_unlock(&info->bfs_lock);
1da177e4 LT	95	iput(inode);
	96	return -ENOSPC;
	97	}
f433dc56	98	set_bit(ino, info->si_imap);
1da177e4	99	info->si_freei--;
e6ecdc70	100	inode_init_owner(inode, dir, mode);
02027d42	101	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
ba52de12	102	inode->i_blocks = 0;
1da177e4 LT	103	inode->i_op = &bfs_file_inops;
	104	inode->i_fop = &bfs_file_operations;
	105	inode->i_mapping->a_ops = &bfs_aops;
1da177e4	106	inode->i_ino = ino;
ce0fe7e7	107	BFS_I(inode)->i_dsk_ino = ino;
1da177e4 LT	108	BFS_I(inode)->i_sblock = 0;
	109	BFS_I(inode)->i_eblock = 0;
	110	insert_inode_hash(inode);
	111	mark_inode_dirty(inode);
1da85fdf	112	bfs_dump_imap("create", s);
1da177e4	113
f433dc56 DV	114	err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
f433dc56 DV	115	inode->i_ino);
1da177e4	116	if (err) {
9a53c3a7	117	inode_dec_link_count(inode);
3f165e4c	118	mutex_unlock(&info->bfs_lock);
1558182f	119	iput(inode);
1da177e4 LT	120	return err;
1da177e4 LT	121	}
3f165e4c	122	mutex_unlock(&info->bfs_lock);
1da177e4 LT	123	d_instantiate(dentry, inode);
	124	return 0;
	125	}
	126
f433dc56	127	static struct dentry bfs_lookup(struct inode dir, struct dentry *dentry,
00cd8dd3	128	unsigned int flags)
1da177e4	129	{
f433dc56 DV	130	struct inode *inode = NULL;
	131	struct buffer_head *bh;
	132	struct bfs_dirent *de;
3f165e4c	133	struct bfs_sb_info *info = BFS_SB(dir->i_sb);
1da177e4 LT	134
	135	if (dentry->d_name.len > BFS_NAMELEN)
	136	return ERR_PTR(-ENAMETOOLONG);
	137
3f165e4c	138	mutex_lock(&info->bfs_lock);
1da177e4 LT	139	bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
1da177e4 LT	140	if (bh) {
fac92bec	141	unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
1da177e4	142	brelse(bh);
e33ab086 DH	143	inode = bfs_iget(dir->i_sb, ino);
e33ab086 DH	144	if (IS_ERR(inode)) {
3f165e4c	145	mutex_unlock(&info->bfs_lock);
e33ab086	146	return ERR_CAST(inode);
1da177e4 LT	147	}
1da177e4 LT	148	}
3f165e4c	149	mutex_unlock(&info->bfs_lock);
1da177e4 LT	150	d_add(dentry, inode);
	151	return NULL;
	152	}
	153
f433dc56 DV	154	static int bfs_link(struct dentry old, struct inode dir,
f433dc56 DV	155	struct dentry *new)
1da177e4	156	{
2b0143b5	157	struct inode *inode = d_inode(old);
3f165e4c	158	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
1da177e4 LT	159	int err;
1da177e4 LT	160
3f165e4c	161	mutex_lock(&info->bfs_lock);
f433dc56 DV	162	err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
f433dc56 DV	163	inode->i_ino);
1da177e4	164	if (err) {
3f165e4c	165	mutex_unlock(&info->bfs_lock);
1da177e4 LT	166	return err;
1da177e4 LT	167	}
d8c76e6f	168	inc_nlink(inode);
02027d42	169	inode->i_ctime = current_time(inode);
1da177e4	170	mark_inode_dirty(inode);
7de9c6ee	171	ihold(inode);
1da177e4	172	d_instantiate(new, inode);
3f165e4c	173	mutex_unlock(&info->bfs_lock);
1da177e4 LT	174	return 0;
	175	}
	176
f433dc56	177	static int bfs_unlink(struct inode dir, struct dentry dentry)
1da177e4 LT	178	{
1da177e4 LT	179	int error = -ENOENT;
2b0143b5	180	struct inode *inode = d_inode(dentry);
f433dc56 DV	181	struct buffer_head *bh;
f433dc56 DV	182	struct bfs_dirent *de;
3f165e4c	183	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
1da177e4	184
3f165e4c	185	mutex_lock(&info->bfs_lock);
1da177e4	186	bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
f433dc56	187	if (!bh \|\| (le16_to_cpu(de->ino) != inode->i_ino))
1da177e4 LT	188	goto out_brelse;
	189
	190	if (!inode->i_nlink) {
f433dc56 DV	191	printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
	192	inode->i_sb->s_id, inode->i_ino,
	193	inode->i_nlink);
bfe86848	194	set_nlink(inode, 1);
1da177e4 LT	195	}
1da177e4 LT	196	de->ino = 0;
4427f0c3	197	mark_buffer_dirty_inode(bh, dir);
02027d42	198	dir->i_ctime = dir->i_mtime = current_time(dir);
1da177e4	199	mark_inode_dirty(dir);
1da177e4	200	inode->i_ctime = dir->i_ctime;
9a53c3a7	201	inode_dec_link_count(inode);
1da177e4 LT	202	error = 0;
	203
	204	out_brelse:
	205	brelse(bh);
3f165e4c	206	mutex_unlock(&info->bfs_lock);
1da177e4 LT	207	return error;
	208	}
	209
f433dc56	210	static int bfs_rename(struct inode old_dir, struct dentry old_dentry,
f03b8ad8 MS	211	struct inode new_dir, struct dentry new_dentry,
f03b8ad8 MS	212	unsigned int flags)
1da177e4	213	{
f433dc56 DV	214	struct inode old_inode, new_inode;
	215	struct buffer_head old_bh, new_bh;
	216	struct bfs_dirent old_de, new_de;
3f165e4c	217	struct bfs_sb_info *info;
1da177e4 LT	218	int error = -ENOENT;
1da177e4 LT	219
f03b8ad8 MS	220	if (flags & ~RENAME_NOREPLACE)
	221	return -EINVAL;
	222
1da177e4	223	old_bh = new_bh = NULL;
2b0143b5	224	old_inode = d_inode(old_dentry);
1da177e4 LT	225	if (S_ISDIR(old_inode->i_mode))
	226	return -EINVAL;
	227
3f165e4c DV	228	info = BFS_SB(old_inode->i_sb);
	229
	230	mutex_lock(&info->bfs_lock);
1da177e4 LT	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;
2b0143b5	239	new_inode = d_inode(new_dentry);
1da177e4 LT	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;
02027d42	257	old_dir->i_ctime = old_dir->i_mtime = current_time(old_dir);
1da177e4 LT	258	mark_inode_dirty(old_dir);
1da177e4 LT	259	if (new_inode) {
02027d42	260	new_inode->i_ctime = current_time(new_inode);
9a53c3a7	261	inode_dec_link_count(new_inode);
1da177e4	262	}
4427f0c3	263	mark_buffer_dirty_inode(old_bh, old_dir);
1da177e4 LT	264	error = 0;
	265
	266	end_rename:
3f165e4c	267	mutex_unlock(&info->bfs_lock);
1da177e4 LT	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)
c3fe5872	301	return -EIO;
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	307	dir->i_size += BFS_DIRENT_SIZE;
02027d42	308	dir->i_ctime = current_time(dir);
1da177e4	309	}
02027d42	310	dir->i_mtime = current_time(dir);
1da177e4	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;
4427f0c3	316	mark_buffer_dirty_inode(bh, dir);
1da177e4 LT	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	}