/* * 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 void *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 void *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 NULL; }