ia64/linux-2.6.18-xen.hg

view fs/jffs2/symlink.c @ 0:831230e53067

Import 2.6.18 from kernel.org tarball.
author Ian Campbell <ian.campbell@xensource.com>
date Wed Apr 11 14:15:44 2007 +0100 (2007-04-11)
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1 /*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright (C) 2001, 2002 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 * $Id: symlink.c,v 1.19 2005/11/07 11:14:42 gleixner Exp $
11 *
12 */
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/fs.h>
18 #include <linux/namei.h>
19 #include "nodelist.h"
21 static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd);
23 struct inode_operations jffs2_symlink_inode_operations =
24 {
25 .readlink = generic_readlink,
26 .follow_link = jffs2_follow_link,
27 .permission = jffs2_permission,
28 .setattr = jffs2_setattr,
29 .setxattr = jffs2_setxattr,
30 .getxattr = jffs2_getxattr,
31 .listxattr = jffs2_listxattr,
32 .removexattr = jffs2_removexattr
33 };
35 static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd)
36 {
37 struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
38 char *p = (char *)f->target;
40 /*
41 * We don't acquire the f->sem mutex here since the only data we
42 * use is f->target.
43 *
44 * 1. If we are here the inode has already built and f->target has
45 * to point to the target path.
46 * 2. Nobody uses f->target (if the inode is symlink's inode). The
47 * exception is inode freeing function which frees f->target. But
48 * it can't be called while we are here and before VFS has
49 * stopped using our f->target string which we provide by means of
50 * nd_set_link() call.
51 */
53 if (!p) {
54 printk(KERN_ERR "jffs2_follow_link(): can't find symlink taerget\n");
55 p = ERR_PTR(-EIO);
56 }
57 D1(printk(KERN_DEBUG "jffs2_follow_link(): target path is '%s'\n", (char *) f->target));
59 nd_set_link(nd, p);
61 /*
62 * We will unlock the f->sem mutex but VFS will use the f->target string. This is safe
63 * since the only way that may cause f->target to be changed is iput() operation.
64 * But VFS will not use f->target after iput() has been called.
65 */
66 return NULL;
67 }