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

/*
 *  linux/fs/affs/dir.c
 *
 *  (c) 1996  Hans-Joachim Widmaier - Rewritten
 *
 *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
 *
 *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
 *
 *  (C) 1991  Linus Torvalds - minix filesystem
 *
 *  affs directory handling functions
 *
 */

#include "affs.h"

static int affs_readdir(struct file *, void *, filldir_t);

const struct file_operations affs_dir_operations = {
	.read		= generic_read_dir,
	.llseek		= generic_file_llseek,
	.readdir	= affs_readdir,
	.fsync		= file_fsync,
};

/*
 * directories can handle most operations...
 */
const struct inode_operations affs_dir_inode_operations = {
	.create		= affs_create,
	.lookup		= affs_lookup,
	.link		= affs_link,
	.unlink		= affs_unlink,
	.symlink	= affs_symlink,
	.mkdir		= affs_mkdir,
	.rmdir		= affs_rmdir,
	.rename		= affs_rename,
	.setattr	= affs_notify_change,
};

static int
affs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct inode		*inode = filp->f_path.dentry->d_inode;
	struct super_block	*sb = inode->i_sb;
	struct buffer_head	*dir_bh;
	struct buffer_head	*fh_bh;
	unsigned char		*name;
	int			 namelen;
	u32			 i;
	int			 hash_pos;
	int			 chain_pos;
	u32			 f_pos;
	u32			 ino;
	int			 stored;
	int			 res;

	pr_debug("AFFS: readdir(ino=%lu,f_pos=%lx)\n",inode->i_ino,(unsigned long)filp->f_pos);

	stored = 0;
	res    = -EIO;
	dir_bh = NULL;
	fh_bh  = NULL;
	f_pos  = filp->f_pos;

	if (f_pos == 0) {
		filp->private_data = (void *)0;
		if (filldir(dirent, ".", 1, f_pos, inode->i_ino, DT_DIR) < 0)
			return 0;
		filp->f_pos = f_pos = 1;
		stored++;
	}
	if (f_pos == 1) {
		if (filldir(dirent, "..", 2, f_pos, parent_ino(filp->f_path.dentry), DT_DIR) < 0)
			return stored;
		filp->f_pos = f_pos = 2;
		stored++;
	}

	affs_lock_dir(inode);
	chain_pos = (f_pos - 2) & 0xffff;
	hash_pos  = (f_pos - 2) >> 16;
	if (chain_pos == 0xffff) {
		affs_warning(sb, "readdir", "More than 65535 entries in chain");
		chain_pos = 0;
		hash_pos++;
		filp->f_pos = ((hash_pos << 16) | chain_pos) + 2;
	}
	dir_bh = affs_bread(sb, inode->i_ino);
	if (!dir_bh)
		goto readdir_out;

	/* If the directory hasn't changed since the last call to readdir(),
	 * we can jump directly to where we left off.
	 */
	ino = (u32)(long)filp->private_data;
	if (ino && filp->f_version == inode->i_version) {
		pr_debug("AFFS: readdir() left off=%d\n", ino);
		goto inside;
	}

	ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
	for (i = 0; ino && i < chain_pos; i++) {
		fh_bh = affs_bread(sb, ino);
		if (!fh_bh) {
			affs_error(sb, "readdir","Cannot read block %d", i);
			goto readdir_out;
		}
		ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
		affs_brelse(fh_bh);
		fh_bh = NULL;
	}
	if (ino)
		goto inside;
	hash_pos++;

	for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
		ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
		if (!ino)
			continue;
		f_pos = (hash_pos << 16) + 2;
inside:
		do {
			fh_bh = affs_bread(sb, ino);
			if (!fh_bh) {
				affs_error(sb, "readdir","Cannot read block %d", ino);
				goto readdir_done;
			}

			namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], (u8)30);
			name = AFFS_TAIL(sb, fh_bh)->name + 1;
			pr_debug("AFFS: readdir(): filldir(\"%.*s\", ino=%u), hash=%d, f_pos=%x\n",
				 namelen, name, ino, hash_pos, f_pos);
			if (filldir(dirent, name, namelen, f_pos, ino, DT_UNKNOWN) < 0)
				goto readdir_done;
			stored++;
			f_pos++;
			ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
			affs_brelse(fh_bh);
			fh_bh = NULL;
		} while (ino);
	}
readdir_done:
	filp->f_pos = f_pos;
	filp->f_version = inode->i_version;
	filp->private_data = (void *)(long)ino;
	res = stored;

readdir_out:
	affs_brelse(dir_bh);
	affs_brelse(fh_bh);
	affs_unlock_dir(inode);
	pr_debug("AFFS: readdir()=%d\n", stored);
	return res;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/affs/dir.c
	3	*
	4	* (c) 1996 Hans-Joachim Widmaier - Rewritten
	5	*
	6	* (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
	7	*
	8	* (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
	9	*
	10	* (C) 1991 Linus Torvalds - minix filesystem
	11	*
	12	* affs directory handling functions
	13	*
	14	*/
	15
	16	#include "affs.h"
	17
	18	static int affs_readdir(struct file , void , filldir_t);
	19
4b6f5d20	20	const struct file_operations affs_dir_operations = {
1da177e4	21	.read = generic_read_dir,
59af1584	22	.llseek = generic_file_llseek,
1da177e4 LT	23	.readdir = affs_readdir,
	24	.fsync = file_fsync,
	25	};
	26
	27	/*
	28	* directories can handle most operations...
	29	*/
754661f1	30	const struct inode_operations affs_dir_inode_operations = {
1da177e4 LT	31	.create = affs_create,
	32	.lookup = affs_lookup,
	33	.link = affs_link,
	34	.unlink = affs_unlink,
	35	.symlink = affs_symlink,
	36	.mkdir = affs_mkdir,
	37	.rmdir = affs_rmdir,
	38	.rename = affs_rename,
	39	.setattr = affs_notify_change,
	40	};
	41
	42	static int
	43	affs_readdir(struct file filp, void dirent, filldir_t filldir)
	44	{
010596cc	45	struct inode *inode = filp->f_path.dentry->d_inode;
1da177e4 LT	46	struct super_block *sb = inode->i_sb;
	47	struct buffer_head *dir_bh;
	48	struct buffer_head *fh_bh;
	49	unsigned char *name;
	50	int namelen;
	51	u32 i;
	52	int hash_pos;
	53	int chain_pos;
	54	u32 f_pos;
	55	u32 ino;
	56	int stored;
	57	int res;
	58
	59	pr_debug("AFFS: readdir(ino=%lu,f_pos=%lx)\n",inode->i_ino,(unsigned long)filp->f_pos);
	60
	61	stored = 0;
	62	res = -EIO;
	63	dir_bh = NULL;
	64	fh_bh = NULL;
	65	f_pos = filp->f_pos;
	66
	67	if (f_pos == 0) {
	68	filp->private_data = (void *)0;
	69	if (filldir(dirent, ".", 1, f_pos, inode->i_ino, DT_DIR) < 0)
	70	return 0;
	71	filp->f_pos = f_pos = 1;
	72	stored++;
	73	}
	74	if (f_pos == 1) {
010596cc	75	if (filldir(dirent, "..", 2, f_pos, parent_ino(filp->f_path.dentry), DT_DIR) < 0)
1da177e4 LT	76	return stored;
	77	filp->f_pos = f_pos = 2;
	78	stored++;
	79	}
	80
	81	affs_lock_dir(inode);
	82	chain_pos = (f_pos - 2) & 0xffff;
	83	hash_pos = (f_pos - 2) >> 16;
	84	if (chain_pos == 0xffff) {
	85	affs_warning(sb, "readdir", "More than 65535 entries in chain");
	86	chain_pos = 0;
	87	hash_pos++;
	88	filp->f_pos = ((hash_pos << 16) \| chain_pos) + 2;
	89	}
	90	dir_bh = affs_bread(sb, inode->i_ino);
	91	if (!dir_bh)
	92	goto readdir_out;
	93
	94	/* If the directory hasn't changed since the last call to readdir(),
	95	* we can jump directly to where we left off.
	96	*/
	97	ino = (u32)(long)filp->private_data;
	98	if (ino && filp->f_version == inode->i_version) {
	99	pr_debug("AFFS: readdir() left off=%d\n", ino);
	100	goto inside;
	101	}
	102
	103	ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
	104	for (i = 0; ino && i < chain_pos; i++) {
	105	fh_bh = affs_bread(sb, ino);
	106	if (!fh_bh) {
	107	affs_error(sb, "readdir","Cannot read block %d", i);
	108	goto readdir_out;
	109	}
	110	ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
	111	affs_brelse(fh_bh);
	112	fh_bh = NULL;
	113	}
	114	if (ino)
	115	goto inside;
	116	hash_pos++;
	117
	118	for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
	119	ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
	120	if (!ino)
	121	continue;
	122	f_pos = (hash_pos << 16) + 2;
	123	inside:
	124	do {
	125	fh_bh = affs_bread(sb, ino);
	126	if (!fh_bh) {
	127	affs_error(sb, "readdir","Cannot read block %d", ino);
	128	goto readdir_done;
	129	}
	130
	131	namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], (u8)30);
	132	name = AFFS_TAIL(sb, fh_bh)->name + 1;
	133	pr_debug("AFFS: readdir(): filldir(\"%.*s\", ino=%u), hash=%d, f_pos=%x\n",
	134	namelen, name, ino, hash_pos, f_pos);
	135	if (filldir(dirent, name, namelen, f_pos, ino, DT_UNKNOWN) < 0)
	136	goto readdir_done;
	137	stored++;
	138	f_pos++;
	139	ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
140	affs_brelse(fh_bh);
141	fh_bh = NULL;
142	} while (ino);
143	}
144	readdir_done:
145	filp->f_pos = f_pos;
146	filp->f_version = inode->i_version;
147	filp->private_data = (void *)(long)ino;
148	res = stored;
149
150	readdir_out:
151	affs_brelse(dir_bh);
152	affs_brelse(fh_bh);
153	affs_unlock_dir(inode);
154	pr_debug("AFFS: readdir()=%d\n", stored);
155	return res;
156	}