1/*
 2 * JFFS2 -- Journalling Flash File System, Version 2.
 3 *
 4 * Copyright © 2001-2007 Red Hat, Inc.
 5 *
 6 * Created by David Woodhouse <dwmw2@infradead.org>
 7 *
 8 * For licensing information, see the file 'LICENCE' in this directory.
 9 *
10 */
11
 
 
 
 
 
12#include "nodelist.h"
13
 
 
14const struct inode_operations jffs2_symlink_inode_operations =
15{
16	.get_link =	simple_get_link,
 
 
17	.setattr =	jffs2_setattr,
 
 
18	.listxattr =	jffs2_listxattr,
 
19};

 1/*
 2 * JFFS2 -- Journalling Flash File System, Version 2.
 3 *
 4 * Copyright © 2001-2007 Red Hat, Inc.
 5 *
 6 * Created by David Woodhouse <dwmw2@infradead.org>
 7 *
 8 * For licensing information, see the file 'LICENCE' in this directory.
 9 *
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/kernel.h>
15#include <linux/fs.h>
16#include <linux/namei.h>
17#include "nodelist.h"
18
19static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd);
20
21const struct inode_operations jffs2_symlink_inode_operations =
22{
23	.readlink =	generic_readlink,
24	.follow_link =	jffs2_follow_link,
25	.get_acl =	jffs2_get_acl,
26	.setattr =	jffs2_setattr,
27	.setxattr =	jffs2_setxattr,
28	.getxattr =	jffs2_getxattr,
29	.listxattr =	jffs2_listxattr,
30	.removexattr =	jffs2_removexattr
31};
32
33static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd)
34{
35	struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
36	char *p = (char *)f->target;
37
38	/*
39	 * We don't acquire the f->sem mutex here since the only data we
40	 * use is f->target.
41	 *
42	 * 1. If we are here the inode has already built and f->target has
43	 * to point to the target path.
44	 * 2. Nobody uses f->target (if the inode is symlink's inode). The
45	 * exception is inode freeing function which frees f->target. But
46	 * it can't be called while we are here and before VFS has
47	 * stopped using our f->target string which we provide by means of
48	 * nd_set_link() call.
49	 */
50
51	if (!p) {
52		pr_err("%s(): can't find symlink target\n", __func__);
53		p = ERR_PTR(-EIO);
54	}
55	jffs2_dbg(1, "%s(): target path is '%s'\n",
56		  __func__, (char *)f->target);
57
58	nd_set_link(nd, p);
59
60	/*
61	 * We will unlock the f->sem mutex but VFS will use the f->target string. This is safe
62	 * since the only way that may cause f->target to be changed is iput() operation.
63	 * But VFS will not use f->target after iput() has been called.
64	 */
65	return NULL;
66}
67