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/*
* JFFS2 -- Journalling Flash File System, Version 2.
*
* Copyright (C) 2001, 2002 Red Hat, Inc.
*
* Created by David Woodhouse <dwmw2@infradead.org>
*
* For licensing information, see the file 'LICENCE' in this directory.
*
* $Id: symlink.c,v 1.16 2005/03/01 10:50:48 dedekind Exp $
*
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include "nodelist.h"
static int jffs2_follow_link(struct dentry *dentry, struct nameidata *nd);
struct inode_operations jffs2_symlink_inode_operations =
{
.readlink = generic_readlink,
.follow_link = jffs2_follow_link,
.setattr = jffs2_setattr
};
static int jffs2_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
char *p = (char *)f->dents;
/*
* We don't acquire the f->sem mutex here since the only data we
* use is f->dents which in case of the symlink inode points to the
* symlink's target path.
*
* 1. If we are here the inode has already built and f->dents has
* to point to the target path.
* 2. Nobody uses f->dents (if the inode is symlink's inode). The
* exception is inode freeing function which frees f->dents. But
* it can't be called while we are here and before VFS has
* stopped using our f->dents string which we provide by means of
* nd_set_link() call.
*/
if (!p) {
printk(KERN_ERR "jffs2_follow_link(): can't find symlink taerget\n");
p = ERR_PTR(-EIO);
} else {
D1(printk(KERN_DEBUG "jffs2_follow_link(): target path is '%s'\n", (char *) f->dents));
}
nd_set_link(nd, p);
/*
* We unlock the f->sem mutex but VFS will use the f->dents string. This is safe
* since the only way that may cause f->dents to be changed is iput() operation.
* But VFS will not use f->dents after iput() has been called.
*/
return 0;
}
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