/* *  linux/fs/affs/symlink.c * *  1995  Hans-Joachim Widmaier - Modified for affs. * *  Copyright (C) 1991, 1992  Linus Torvalds * *  affs symlink handling code */#include <linux/errno.h>#include <linux/sched.h>#include <linux/malloc.h>#include <linux/fs.h>#include <linux/stat.h>#include <linux/affs_fs.h>#include <linux/amigaffs.h>#include <asm/segment.h>#define MIN(a,b) (((a) < (b)) ? (a) : (b))static int affs_readlink(struct inode *, char *, int);static int affs_follow_link(struct inode *, struct inode *, int, int, struct inode **);struct inode_operations affs_symlink_inode_operations = {	NULL,			/* no file-operations */	NULL,			/* create */	NULL,			/* lookup */	NULL,			/* link */	NULL,			/* unlink */	NULL,			/* symlink */	NULL,			/* mkdir */	NULL,			/* rmdir */	NULL,			/* mknod */	NULL,			/* rename */	affs_readlink,		/* readlink */	affs_follow_link,	/* follow_link */	NULL,			/* bmap */	NULL,			/* truncate */	NULL			/* permission */};static intaffs_follow_link(struct inode *dir, struct inode *inode, int flag, int mode,		 struct inode **res_inode){	struct buffer_head	*bh;	struct slink_front	*lf;	char			*buffer;	int			 error;	int			 i, j;	char			 c;	char			 lc;	pr_debug("AFFS: follow_link(ino=%lu)\n",inode->i_ino);	*res_inode = NULL;	if (!dir) {		dir = current->fs->root;		dir->i_count++;	}	if (!inode) {		iput(dir);		return -ENOENT;	}	if (!S_ISLNK(inode->i_mode)) {		iput(dir);		*res_inode = inode;		return 0;	}	if (current->link_count > 5) {		iput(inode);		iput(dir);		return -ELOOP;	}	if (!(buffer = kmalloc(1024,GFP_KERNEL))) {		iput(inode);		iput(dir);		return -ENOSPC;	}	bh = affs_bread(inode->i_dev,inode->i_ino,AFFS_I2BSIZE(inode));	i  = 0;	j  = 0;	if (!bh) {		printk("AFFS: unable to read i-node block %lu\n",inode->i_ino);		kfree(buffer);		iput(inode);		iput(dir);		return -EIO;	}	lf = (struct slink_front *)bh->b_data;	lc = 0;	if (strchr(lf->symname,':')) {		/* Handle assign or volume name */		while (i < 1023 && (c = inode->i_sb->u.affs_sb.s_prefix[i]))			buffer[i++] = c;		while (i < 1023 && lf->symname[j] != ':')			buffer[i++] = lf->symname[j++];		if (i < 1023)			 buffer[i++] = '/';		j++;		lc = '/';	}	while (i < 1023 && (c = lf->symname[j])) {		if (c == '/' && lc == '/' && i < 1020) {	/* parent dir */			buffer[i++] = '.';			buffer[i++] = '.';		}		buffer[i++] = c;		lc = c;		j++;	}	buffer[i] = '\0';	affs_brelse(bh);	iput(inode);	current->link_count++;	error = open_namei(buffer,flag,mode,res_inode,dir);	current->link_count--;	kfree(buffer);	return error;}static intaffs_readlink(struct inode *inode, char *buffer, int buflen){	struct buffer_head	*bh;	struct slink_front	*lf;	int			 i, j;	char			 c;	char			 lc;	pr_debug("AFFS: readlink(ino=%lu,buflen=%d)\n",inode->i_ino,buflen);	if (!S_ISLNK(inode->i_mode)) {		iput(inode);		return -EINVAL;	}	bh = affs_bread(inode->i_dev,inode->i_ino,AFFS_I2BSIZE(inode));	i  = 0;	j  = 0;	if (!bh) {		printk("AFFS: unable to read i-node block %lu\n",inode->i_ino);		goto symlink_end;	}	lf = (struct slink_front *)bh->b_data;	lc = 0;		if (strchr(lf->symname,':')) {		/* Handle assign or volume name */		while (i < buflen && (c = inode->i_sb->u.affs_sb.s_prefix[i])) {			put_user(c,buffer++);			i++;		}		while (i < buflen && (c = lf->symname[j]) != ':') {			put_user(c,buffer++);			i++, j++;		}		if (i < buflen) {			put_user('/',buffer++);			i++, j++;		}		lc = '/';	}	while (i < buflen && (c = lf->symname[j])) {		if (c == '/' && lc == '/' && (i + 3 < buflen)) {	/* parent dir */			put_user('.',buffer++);			put_user('.',buffer++);			i += 2;		}		put_user(c,buffer++);		lc = c;		i++, j++;	}symlink_end:	iput(inode);	affs_brelse(bh);	return i;}