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/*
* JFFS2 -- Journalling Flash File System, Version 2.
*
* Copyright © 2001-2007 Red Hat, Inc.
*
* Created by David Woodhouse <dwmw2@infradead.org>
*
* For licensing information, see the file 'LICENCE' in this directory.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include "nodelist.h"
static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd);
const struct inode_operations jffs2_symlink_inode_operations =
{
.readlink = generic_readlink,
.follow_link = jffs2_follow_link,
.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) {
pr_err("%s(): can't find symlink target\n", __func__);
p = ERR_PTR(-EIO);
}
jffs2_dbg(1, "%s(): target path is '%s'\n",
__func__, (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;
}
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