// SPDX-License-Identifier: GPL-2.0/* *  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 <linux/iversion.h>#include <linux/filelock.h>#include "affs.h" struct affs_dir_data {	unsigned long ino;	u64 cookie;}; static int affs_readdir(struct file *, struct dir_context *); static loff_t affs_dir_llseek(struct file *file, loff_t offset, int whence){	struct affs_dir_data *data = file->private_data; 	return generic_llseek_cookie(file, offset, whence, &data->cookie);} static int affs_dir_open(struct inode *inode, struct file *file){	struct affs_dir_data	*data; 	data = kzalloc_obj(struct affs_dir_data);	if (!data)		return -ENOMEM;	file->private_data = data;	return 0;} static int affs_dir_release(struct inode *inode, struct file *file){	kfree(file->private_data);	return 0;} const struct file_operations affs_dir_operations = {	.open		= affs_dir_open,	.read		= generic_read_dir,	.llseek		= affs_dir_llseek,	.iterate_shared	= affs_readdir,	.fsync		= affs_file_fsync,	.release	= affs_dir_release,	.setlease	= generic_setlease,}; /* * 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_rename2,	.setattr	= affs_setattr,}; static intaffs_readdir(struct file *file, struct dir_context *ctx){	struct inode		*inode = file_inode(file);	struct affs_dir_data	*data = file->private_data;	struct super_block	*sb = inode->i_sb;	struct buffer_head	*dir_bh = NULL;	struct buffer_head	*fh_bh = NULL;	unsigned char		*name;	int			 namelen;	u32			 i;	int			 hash_pos;	int			 chain_pos;	u32			 ino;	int			 error = 0; 	pr_debug("%s(ino=%llu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos); 	if (ctx->pos < 2) {		data->ino = 0;		if (!dir_emit_dots(file, ctx))			return 0;	} 	affs_lock_dir(inode);	chain_pos = (ctx->pos - 2) & 0xffff;	hash_pos  = (ctx->pos - 2) >> 16;	if (chain_pos == 0xffff) {		affs_warning(sb, "readdir", "More than 65535 entries in chain");		chain_pos = 0;		hash_pos++;		ctx->pos = ((hash_pos << 16) | chain_pos) + 2;	}	dir_bh = affs_bread(sb, inode->i_ino);	if (!dir_bh)		goto out_unlock_dir; 	/* If the directory hasn't changed since the last call to readdir(),	 * we can jump directly to where we left off.	 */	ino = data->ino;	if (ino && inode_eq_iversion(inode, data->cookie)) {		pr_debug("readdir() left off=%d\n", ino);		goto inside;	}	if (hash_pos >= AFFS_SB(sb)->s_hashsize)		goto done; 	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);			error = -EIO;			goto out_brelse_dir;		}		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;		ctx->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);				break;			} 			namelen = min(AFFS_TAIL(sb, fh_bh)->name[0],				      (u8)AFFSNAMEMAX);			name = AFFS_TAIL(sb, fh_bh)->name + 1;			pr_debug("readdir(): dir_emit(\"%.*s\", ino=%u), hash=%d, f_pos=%llx\n",				 namelen, name, ino, hash_pos, ctx->pos); 			if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN))				goto done;			ctx->pos++;			ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);			affs_brelse(fh_bh);			fh_bh = NULL;		} while (ino);	}done:	data->cookie = inode_query_iversion(inode);	data->ino = ino;	affs_brelse(fh_bh); out_brelse_dir:	affs_brelse(dir_bh); out_unlock_dir:	affs_unlock_dir(inode);	return error;}