[mirror_ubuntu-artful-kernel.git] / fs / bfs / dir.c

/*
 *	fs/bfs/dir.c
 *	BFS directory operations.
 *	Copyright (C) 1999,2000  Tigran Aivazian <tigran@veritas.com>
 *      Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 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
1da177e4 LT	1	/*
	2	* fs/bfs/dir.c
	3	* BFS directory operations.
	4	* Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>
fac92bec	5	* Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 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
81b9f66e	29	static int bfs_readdir(struct file f, struct dir_context ctx)
1da177e4	30	{
496ad9aa	31	struct inode *dir = file_inode(f);
f433dc56 DV	32	struct buffer_head *bh;
f433dc56 DV	33	struct bfs_dirent *de;
1da177e4 LT	34	unsigned int offset;
	35	int block;
	36
81b9f66e	37	if (ctx->pos & (BFS_DIRENT_SIZE - 1)) {
f433dc56	38	printf("Bad f_pos=%08lx for %s:%08lx\n",
81b9f66e	39	(unsigned long)ctx->pos,
f433dc56	40	dir->i_sb->s_id, dir->i_ino);
81b9f66e	41	return -EINVAL;
1da177e4 LT	42	}
1da177e4 LT	43
81b9f66e AV	44	while (ctx->pos < dir->i_size) {
	45	offset = ctx->pos & (BFS_BSIZE - 1);
	46	block = BFS_I(dir)->i_sblock + (ctx->pos >> BFS_BSIZE_BITS);
1da177e4 LT	47	bh = sb_bread(dir->i_sb, block);
1da177e4 LT	48	if (!bh) {
81b9f66e	49	ctx->pos += BFS_BSIZE - offset;
1da177e4 LT	50	continue;
	51	}
	52	do {
	53	de = (struct bfs_dirent *)(bh->b_data + offset);
	54	if (de->ino) {
	55	int size = strnlen(de->name, BFS_NAMELEN);
81b9f66e	56	if (!dir_emit(ctx, de->name, size,
f433dc56	57	le16_to_cpu(de->ino),
81b9f66e	58	DT_UNKNOWN)) {
1da177e4	59	brelse(bh);
1da177e4 LT	60	return 0;
	61	}
	62	}
	63	offset += BFS_DIRENT_SIZE;
81b9f66e AV	64	ctx->pos += BFS_DIRENT_SIZE;
81b9f66e AV	65	} while ((offset < BFS_BSIZE) && (ctx->pos < dir->i_size));
1da177e4 LT	66	brelse(bh);
1da177e4 LT	67	}
81b9f66e	68	return 0;
1da177e4 LT	69	}
1da177e4 LT	70
4b6f5d20	71	const struct file_operations bfs_dir_operations = {
1da177e4	72	.read = generic_read_dir,
c51da20c	73	.iterate_shared = bfs_readdir,
1b061d92	74	.fsync = generic_file_fsync,
3222a3e5	75	.llseek = generic_file_llseek,
1da177e4 LT	76	};
1da177e4 LT	77
4acdaf27	78	static int bfs_create(struct inode dir, struct dentry dentry, umode_t mode,
ebfc3b49	79	bool excl)
1da177e4 LT	80	{
1da177e4 LT	81	int err;
f433dc56 DV	82	struct inode *inode;
	83	struct super_block *s = dir->i_sb;
	84	struct bfs_sb_info *info = BFS_SB(s);
1da177e4 LT	85	unsigned long ino;
	86
	87	inode = new_inode(s);
	88	if (!inode)
c3fe5872	89	return -ENOMEM;
3f165e4c	90	mutex_lock(&info->bfs_lock);
69b195be	91	ino = find_first_zero_bit(info->si_imap, info->si_lasti + 1);
1da177e4	92	if (ino > info->si_lasti) {
3f165e4c	93	mutex_unlock(&info->bfs_lock);
1da177e4 LT	94	iput(inode);
	95	return -ENOSPC;
	96	}
f433dc56	97	set_bit(ino, info->si_imap);
1da177e4	98	info->si_freei--;
e6ecdc70	99	inode_init_owner(inode, dir, mode);
02027d42	100	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
ba52de12	101	inode->i_blocks = 0;
1da177e4 LT	102	inode->i_op = &bfs_file_inops;
	103	inode->i_fop = &bfs_file_operations;
	104	inode->i_mapping->a_ops = &bfs_aops;
1da177e4	105	inode->i_ino = ino;
ce0fe7e7	106	BFS_I(inode)->i_dsk_ino = ino;
1da177e4 LT	107	BFS_I(inode)->i_sblock = 0;
	108	BFS_I(inode)->i_eblock = 0;
	109	insert_inode_hash(inode);
	110	mark_inode_dirty(inode);
1da85fdf	111	bfs_dump_imap("create", s);
1da177e4	112
f433dc56 DV	113	err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
f433dc56 DV	114	inode->i_ino);
1da177e4	115	if (err) {
9a53c3a7	116	inode_dec_link_count(inode);
3f165e4c	117	mutex_unlock(&info->bfs_lock);
1558182f	118	iput(inode);
1da177e4 LT	119	return err;
1da177e4 LT	120	}
3f165e4c	121	mutex_unlock(&info->bfs_lock);
1da177e4 LT	122	d_instantiate(dentry, inode);
	123	return 0;
	124	}
	125
f433dc56	126	static struct dentry bfs_lookup(struct inode dir, struct dentry *dentry,
00cd8dd3	127	unsigned int flags)
1da177e4	128	{
f433dc56 DV	129	struct inode *inode = NULL;
	130	struct buffer_head *bh;
	131	struct bfs_dirent *de;
3f165e4c	132	struct bfs_sb_info *info = BFS_SB(dir->i_sb);
1da177e4 LT	133
	134	if (dentry->d_name.len > BFS_NAMELEN)
	135	return ERR_PTR(-ENAMETOOLONG);
	136
3f165e4c	137	mutex_lock(&info->bfs_lock);
1da177e4 LT	138	bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
1da177e4 LT	139	if (bh) {
fac92bec	140	unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
1da177e4	141	brelse(bh);
e33ab086 DH	142	inode = bfs_iget(dir->i_sb, ino);
e33ab086 DH	143	if (IS_ERR(inode)) {
3f165e4c	144	mutex_unlock(&info->bfs_lock);
e33ab086	145	return ERR_CAST(inode);
1da177e4 LT	146	}
1da177e4 LT	147	}
3f165e4c	148	mutex_unlock(&info->bfs_lock);
1da177e4 LT	149	d_add(dentry, inode);
	150	return NULL;
	151	}
	152
f433dc56 DV	153	static int bfs_link(struct dentry old, struct inode dir,
f433dc56 DV	154	struct dentry *new)
1da177e4	155	{
2b0143b5	156	struct inode *inode = d_inode(old);
3f165e4c	157	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
1da177e4 LT	158	int err;
1da177e4 LT	159
3f165e4c	160	mutex_lock(&info->bfs_lock);
f433dc56 DV	161	err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
f433dc56 DV	162	inode->i_ino);
1da177e4	163	if (err) {
3f165e4c	164	mutex_unlock(&info->bfs_lock);
1da177e4 LT	165	return err;
1da177e4 LT	166	}
d8c76e6f	167	inc_nlink(inode);
02027d42	168	inode->i_ctime = current_time(inode);
1da177e4	169	mark_inode_dirty(inode);
7de9c6ee	170	ihold(inode);
1da177e4	171	d_instantiate(new, inode);
3f165e4c	172	mutex_unlock(&info->bfs_lock);
1da177e4 LT	173	return 0;
	174	}
	175
f433dc56	176	static int bfs_unlink(struct inode dir, struct dentry dentry)
1da177e4 LT	177	{
1da177e4 LT	178	int error = -ENOENT;
2b0143b5	179	struct inode *inode = d_inode(dentry);
f433dc56 DV	180	struct buffer_head *bh;
f433dc56 DV	181	struct bfs_dirent *de;
3f165e4c	182	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
1da177e4	183
3f165e4c	184	mutex_lock(&info->bfs_lock);
1da177e4	185	bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
f433dc56	186	if (!bh \|\| (le16_to_cpu(de->ino) != inode->i_ino))
1da177e4 LT	187	goto out_brelse;
	188
	189	if (!inode->i_nlink) {
f433dc56 DV	190	printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
	191	inode->i_sb->s_id, inode->i_ino,
	192	inode->i_nlink);
bfe86848	193	set_nlink(inode, 1);
1da177e4 LT	194	}
1da177e4 LT	195	de->ino = 0;
4427f0c3	196	mark_buffer_dirty_inode(bh, dir);
02027d42	197	dir->i_ctime = dir->i_mtime = current_time(dir);
1da177e4	198	mark_inode_dirty(dir);
1da177e4	199	inode->i_ctime = dir->i_ctime;
9a53c3a7	200	inode_dec_link_count(inode);
1da177e4 LT	201	error = 0;
	202
	203	out_brelse:
	204	brelse(bh);
3f165e4c	205	mutex_unlock(&info->bfs_lock);
1da177e4 LT	206	return error;
	207	}
	208
f433dc56	209	static int bfs_rename(struct inode old_dir, struct dentry old_dentry,
f03b8ad8 MS	210	struct inode new_dir, struct dentry new_dentry,
f03b8ad8 MS	211	unsigned int flags)
1da177e4	212	{
f433dc56 DV	213	struct inode old_inode, new_inode;
	214	struct buffer_head old_bh, new_bh;
	215	struct bfs_dirent old_de, new_de;
3f165e4c	216	struct bfs_sb_info *info;
1da177e4 LT	217	int error = -ENOENT;
1da177e4 LT	218
f03b8ad8 MS	219	if (flags & ~RENAME_NOREPLACE)
	220	return -EINVAL;
	221
1da177e4	222	old_bh = new_bh = NULL;
2b0143b5	223	old_inode = d_inode(old_dentry);
1da177e4 LT	224	if (S_ISDIR(old_inode->i_mode))
	225	return -EINVAL;
	226
3f165e4c DV	227	info = BFS_SB(old_inode->i_sb);
	228
	229	mutex_lock(&info->bfs_lock);
1da177e4 LT	230	old_bh = bfs_find_entry(old_dir,
	231	old_dentry->d_name.name,
	232	old_dentry->d_name.len, &old_de);
	233
f433dc56	234	if (!old_bh \|\| (le16_to_cpu(old_de->ino) != old_inode->i_ino))
1da177e4 LT	235	goto end_rename;
	236
	237	error = -EPERM;
2b0143b5	238	new_inode = d_inode(new_dentry);
1da177e4 LT	239	new_bh = bfs_find_entry(new_dir,
	240	new_dentry->d_name.name,
	241	new_dentry->d_name.len, &new_de);
	242
	243	if (new_bh && !new_inode) {
	244	brelse(new_bh);
	245	new_bh = NULL;
	246	}
	247	if (!new_bh) {
	248	error = bfs_add_entry(new_dir,
	249	new_dentry->d_name.name,
f433dc56 DV	250	new_dentry->d_name.len,
f433dc56 DV	251	old_inode->i_ino);
1da177e4 LT	252	if (error)
	253	goto end_rename;
	254	}
	255	old_de->ino = 0;
02027d42	256	old_dir->i_ctime = old_dir->i_mtime = current_time(old_dir);
1da177e4 LT	257	mark_inode_dirty(old_dir);
1da177e4 LT	258	if (new_inode) {
02027d42	259	new_inode->i_ctime = current_time(new_inode);
9a53c3a7	260	inode_dec_link_count(new_inode);
1da177e4	261	}
4427f0c3	262	mark_buffer_dirty_inode(old_bh, old_dir);
1da177e4 LT	263	error = 0;
	264
	265	end_rename:
3f165e4c	266	mutex_unlock(&info->bfs_lock);
1da177e4 LT	267	brelse(old_bh);
	268	brelse(new_bh);
	269	return error;
	270	}
	271
754661f1	272	const struct inode_operations bfs_dir_inops = {
1da177e4 LT	273	.create = bfs_create,
	274	.lookup = bfs_lookup,
	275	.link = bfs_link,
	276	.unlink = bfs_unlink,
	277	.rename = bfs_rename,
	278	};
	279
f433dc56 DV	280	static int bfs_add_entry(struct inode dir, const unsigned char name,
f433dc56 DV	281	int namelen, int ino)
1da177e4	282	{
f433dc56 DV	283	struct buffer_head *bh;
	284	struct bfs_dirent *de;
	285	int block, sblock, eblock, off, pos;
1da177e4 LT	286	int i;
	287
	288	dprintf("name=%s, namelen=%d\n", name, namelen);
	289
	290	if (!namelen)
	291	return -ENOENT;
	292	if (namelen > BFS_NAMELEN)
	293	return -ENAMETOOLONG;
	294
	295	sblock = BFS_I(dir)->i_sblock;
	296	eblock = BFS_I(dir)->i_eblock;
f433dc56	297	for (block = sblock; block <= eblock; block++) {
1da177e4	298	bh = sb_bread(dir->i_sb, block);
f433dc56	299	if (!bh)
c3fe5872	300	return -EIO;
f433dc56	301	for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
1da177e4	302	de = (struct bfs_dirent *)(bh->b_data + off);
1da177e4	303	if (!de->ino) {
f433dc56 DV	304	pos = (block - sblock) * BFS_BSIZE + off;
f433dc56 DV	305	if (pos >= dir->i_size) {
1da177e4	306	dir->i_size += BFS_DIRENT_SIZE;
02027d42	307	dir->i_ctime = current_time(dir);
1da177e4	308	}
02027d42	309	dir->i_mtime = current_time(dir);
1da177e4	310	mark_inode_dirty(dir);
fac92bec	311	de->ino = cpu_to_le16((u16)ino);
f433dc56 DV	312	for (i = 0; i < BFS_NAMELEN; i++)
	313	de->name[i] =
	314	(i < namelen) ? name[i] : 0;
4427f0c3	315	mark_buffer_dirty_inode(bh, dir);
1da177e4 LT	316	brelse(bh);
	317	return 0;
	318	}
	319	}
	320	brelse(bh);
	321	}
	322	return -ENOSPC;
	323	}
	324
f433dc56 DV	325	static inline int bfs_namecmp(int len, const unsigned char *name,
f433dc56 DV	326	const char *buffer)
1da177e4	327	{
f433dc56	328	if ((len < BFS_NAMELEN) && buffer[len])
1da177e4 LT	329	return 0;
	330	return !memcmp(name, buffer, len);
	331	}
	332
f433dc56 DV	333	static struct buffer_head bfs_find_entry(struct inode dir,
	334	const unsigned char *name, int namelen,
	335	struct bfs_dirent **res_dir)
1da177e4	336	{
f433dc56 DV	337	unsigned long block = 0, offset = 0;
	338	struct buffer_head *bh = NULL;
	339	struct bfs_dirent *de;
1da177e4 LT	340
	341	*res_dir = NULL;
	342	if (namelen > BFS_NAMELEN)
	343	return NULL;
f433dc56	344
1da177e4 LT	345	while (block * BFS_BSIZE + offset < dir->i_size) {
	346	if (!bh) {
	347	bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
	348	if (!bh) {
	349	block++;
	350	continue;
	351	}
	352	}
	353	de = (struct bfs_dirent *)(bh->b_data + offset);
	354	offset += BFS_DIRENT_SIZE;
f433dc56 DV	355	if (le16_to_cpu(de->ino) &&
f433dc56 DV	356	bfs_namecmp(namelen, name, de->name)) {
1da177e4 LT	357	*res_dir = de;
	358	return bh;
	359	}
	360	if (offset < bh->b_size)
	361	continue;
	362	brelse(bh);
	363	bh = NULL;
	364	offset = 0;
	365	block++;
	366	}
	367	brelse(bh);
	368	return NULL;
	369	}