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1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
c00c310e 4 * Copyright © 2001-2007 Red Hat, Inc.
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5 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
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10 */
11
1da177e4 12#include <linux/kernel.h>
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13#include <linux/fs.h>
14#include <linux/namei.h>
15#include "nodelist.h"
16
008b150a 17static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd);
1da177e4 18
92e1d5be 19const struct inode_operations jffs2_symlink_inode_operations =
182ec4ee 20{
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21 .readlink = generic_readlink,
22 .follow_link = jffs2_follow_link,
18f4c644 23 .check_acl = jffs2_check_acl,
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24 .setattr = jffs2_setattr,
25 .setxattr = jffs2_setxattr,
26 .getxattr = jffs2_getxattr,
27 .listxattr = jffs2_listxattr,
28 .removexattr = jffs2_removexattr
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29};
30
008b150a 31static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd)
1da177e4 32{
32f1a95d 33 struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
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34 char *p = (char *)f->target;
35
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36 /*
37 * We don't acquire the f->sem mutex here since the only data we
2b79adcc 38 * use is f->target.
32f1a95d 39 *
2b79adcc 40 * 1. If we are here the inode has already built and f->target has
32f1a95d 41 * to point to the target path.
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42 * 2. Nobody uses f->target (if the inode is symlink's inode). The
43 * exception is inode freeing function which frees f->target. But
32f1a95d 44 * it can't be called while we are here and before VFS has
2b79adcc 45 * stopped using our f->target string which we provide by means of
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46 * nd_set_link() call.
47 */
182ec4ee 48
2fb1e308 49 if (!p) {
c7cf0c68 50 printk(KERN_ERR "jffs2_follow_link(): can't find symlink target\n");
2fb1e308 51 p = ERR_PTR(-EIO);
32f1a95d 52 }
2b79adcc 53 D1(printk(KERN_DEBUG "jffs2_follow_link(): target path is '%s'\n", (char *) f->target));
32f1a95d 54
2fb1e308 55 nd_set_link(nd, p);
182ec4ee 56
32f1a95d 57 /*
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58 * We will unlock the f->sem mutex but VFS will use the f->target string. This is safe
59 * since the only way that may cause f->target to be changed is iput() operation.
60 * But VFS will not use f->target after iput() has been called.
32f1a95d 61 */
008b150a 62 return NULL;
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63}
64