Commit | Line | Data |
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1da177e4 LT |
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 | * | |
182ec4ee | 10 | * $Id: symlink.c,v 1.19 2005/11/07 11:14:42 gleixner Exp $ |
1da177e4 LT |
11 | * |
12 | */ | |
13 | ||
14 | ||
15 | #include <linux/kernel.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/fs.h> | |
18 | #include <linux/namei.h> | |
19 | #include "nodelist.h" | |
20 | ||
008b150a | 21 | static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd); |
1da177e4 LT |
22 | |
23 | struct inode_operations jffs2_symlink_inode_operations = | |
182ec4ee | 24 | { |
1da177e4 LT |
25 | .readlink = generic_readlink, |
26 | .follow_link = jffs2_follow_link, | |
aa98d7cf KK |
27 | .permission = jffs2_permission, |
28 | .setattr = jffs2_setattr, | |
29 | .setxattr = jffs2_setxattr, | |
30 | .getxattr = jffs2_getxattr, | |
31 | .listxattr = jffs2_listxattr, | |
32 | .removexattr = jffs2_removexattr | |
1da177e4 LT |
33 | }; |
34 | ||
008b150a | 35 | static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd) |
1da177e4 | 36 | { |
32f1a95d | 37 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode); |
2b79adcc AB |
38 | char *p = (char *)f->target; |
39 | ||
32f1a95d AB |
40 | /* |
41 | * We don't acquire the f->sem mutex here since the only data we | |
2b79adcc | 42 | * use is f->target. |
32f1a95d | 43 | * |
2b79adcc | 44 | * 1. If we are here the inode has already built and f->target has |
32f1a95d | 45 | * to point to the target path. |
2b79adcc AB |
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 | |
32f1a95d | 48 | * it can't be called while we are here and before VFS has |
2b79adcc | 49 | * stopped using our f->target string which we provide by means of |
32f1a95d AB |
50 | * nd_set_link() call. |
51 | */ | |
182ec4ee | 52 | |
2fb1e308 | 53 | if (!p) { |
32f1a95d | 54 | printk(KERN_ERR "jffs2_follow_link(): can't find symlink taerget\n"); |
2fb1e308 | 55 | p = ERR_PTR(-EIO); |
32f1a95d | 56 | } |
2b79adcc | 57 | D1(printk(KERN_DEBUG "jffs2_follow_link(): target path is '%s'\n", (char *) f->target)); |
32f1a95d | 58 | |
2fb1e308 | 59 | nd_set_link(nd, p); |
182ec4ee | 60 | |
32f1a95d | 61 | /* |
2b79adcc AB |
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. | |
32f1a95d | 65 | */ |
008b150a | 66 | return NULL; |
1da177e4 LT |
67 | } |
68 |