]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. | |
3 | * | |
c00c310e | 4 | * Copyright © 2001-2007 Red Hat, Inc. |
1da177e4 LT |
5 | * |
6 | * Created by David Woodhouse <dwmw2@infradead.org> | |
7 | * | |
8 | * For licensing information, see the file 'LICENCE' in this directory. | |
9 | * | |
1da177e4 LT |
10 | */ |
11 | ||
5a528957 JP |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | ||
1da177e4 | 14 | #include <linux/kernel.h> |
1da177e4 LT |
15 | #include <linux/fs.h> |
16 | #include <linux/namei.h> | |
17 | #include "nodelist.h" | |
18 | ||
008b150a | 19 | static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd); |
1da177e4 | 20 | |
92e1d5be | 21 | const struct inode_operations jffs2_symlink_inode_operations = |
182ec4ee | 22 | { |
1da177e4 LT |
23 | .readlink = generic_readlink, |
24 | .follow_link = jffs2_follow_link, | |
aa98d7cf KK |
25 | .setattr = jffs2_setattr, |
26 | .setxattr = jffs2_setxattr, | |
27 | .getxattr = jffs2_getxattr, | |
28 | .listxattr = jffs2_listxattr, | |
29 | .removexattr = jffs2_removexattr | |
1da177e4 LT |
30 | }; |
31 | ||
008b150a | 32 | static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd) |
1da177e4 | 33 | { |
2b0143b5 | 34 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry)); |
2b79adcc AB |
35 | char *p = (char *)f->target; |
36 | ||
32f1a95d AB |
37 | /* |
38 | * We don't acquire the f->sem mutex here since the only data we | |
2b79adcc | 39 | * use is f->target. |
32f1a95d | 40 | * |
2b79adcc | 41 | * 1. If we are here the inode has already built and f->target has |
32f1a95d | 42 | * to point to the target path. |
2b79adcc AB |
43 | * 2. Nobody uses f->target (if the inode is symlink's inode). The |
44 | * exception is inode freeing function which frees f->target. But | |
32f1a95d | 45 | * it can't be called while we are here and before VFS has |
2b79adcc | 46 | * stopped using our f->target string which we provide by means of |
32f1a95d AB |
47 | * nd_set_link() call. |
48 | */ | |
182ec4ee | 49 | |
2fb1e308 | 50 | if (!p) { |
da320f05 | 51 | pr_err("%s(): can't find symlink target\n", __func__); |
2fb1e308 | 52 | p = ERR_PTR(-EIO); |
32f1a95d | 53 | } |
9c261b33 JP |
54 | jffs2_dbg(1, "%s(): target path is '%s'\n", |
55 | __func__, (char *)f->target); | |
32f1a95d | 56 | |
2fb1e308 | 57 | nd_set_link(nd, p); |
182ec4ee | 58 | |
32f1a95d | 59 | /* |
2b79adcc AB |
60 | * We will unlock the f->sem mutex but VFS will use the f->target string. This is safe |
61 | * since the only way that may cause f->target to be changed is iput() operation. | |
62 | * But VFS will not use f->target after iput() has been called. | |
32f1a95d | 63 | */ |
008b150a | 64 | return NULL; |
1da177e4 LT |
65 | } |
66 |