/* * 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 1.19 2005/11/07 11:14:42 gleixner 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, .permission = jffs2_permission, .setattr = jffs2_setattr, .setxattr = jffs2_setxattr, .getxattr = jffs2_getxattr, .listxattr = jffs2_listxattr, .removexattr = jffs2_removexattr }; 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->target; /* * We don't acquire the f->sem mutex here since the only data we * use is f->target. * * 1. If we are here the inode has already built and f->target has * to point to the target path. * 2. Nobody uses f->target (if the inode is symlink's inode). The * exception is inode freeing function which frees f->target. But * it can't be called while we are here and before VFS has * stopped using our f->target 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); } D1(printk(KERN_DEBUG "jffs2_follow_link(): target path is '%s'\n", (char *) f->target)); nd_set_link(nd, p); /* * We will unlock the f->sem mutex but VFS will use the f->target string. This is safe * since the only way that may cause f->target to be changed is iput() operation. * But VFS will not use f->target after iput() has been called. */ return NULL; }