135 lines
		
	
	
	
		
			3.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			135 lines
		
	
	
	
		
			3.3 KiB
			
		
	
	
	
		
			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 *, struct dir_context *);
 | 
						|
 | 
						|
const struct file_operations affs_dir_operations = {
 | 
						|
	.read		= generic_read_dir,
 | 
						|
	.llseek		= generic_file_llseek,
 | 
						|
	.iterate	= affs_readdir,
 | 
						|
	.fsync		= affs_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 *file, struct dir_context *ctx)
 | 
						|
{
 | 
						|
	struct inode		*inode = file_inode(file);
 | 
						|
	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;
 | 
						|
 | 
						|
	pr_debug("AFFS: readdir(ino=%lu,f_pos=%lx)\n",inode->i_ino,(unsigned long)ctx->pos);
 | 
						|
 | 
						|
	if (ctx->pos < 2) {
 | 
						|
		file->private_data = (void *)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 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)file->private_data;
 | 
						|
	if (ino && file->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);
 | 
						|
			return -EIO;
 | 
						|
		}
 | 
						|
		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)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, (u32)ctx->pos);
 | 
						|
			if (!dir_emit(ctx, name, namelen, ino, DT_UNKNOWN))
 | 
						|
				goto readdir_done;
 | 
						|
			ctx->pos++;
 | 
						|
			ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
 | 
						|
			affs_brelse(fh_bh);
 | 
						|
			fh_bh = NULL;
 | 
						|
		} while (ino);
 | 
						|
	}
 | 
						|
readdir_done:
 | 
						|
	file->f_version = inode->i_version;
 | 
						|
	file->private_data = (void *)(long)ino;
 | 
						|
 | 
						|
readdir_out:
 | 
						|
	affs_brelse(dir_bh);
 | 
						|
	affs_brelse(fh_bh);
 | 
						|
	affs_unlock_dir(inode);
 | 
						|
	return 0;
 | 
						|
}
 |