Commit | Line | Data |
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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 | ||
1da177e4 LT |
12 | #include <linux/kernel.h> |
13 | #include <linux/slab.h> | |
14 | #include <linux/fs.h> | |
15 | #include <linux/namei.h> | |
16 | #include "nodelist.h" | |
17 | ||
008b150a | 18 | static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd); |
1da177e4 | 19 | |
92e1d5be | 20 | const struct inode_operations jffs2_symlink_inode_operations = |
182ec4ee | 21 | { |
1da177e4 LT |
22 | .readlink = generic_readlink, |
23 | .follow_link = jffs2_follow_link, | |
aa98d7cf KK |
24 | .permission = jffs2_permission, |
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 | { |
32f1a95d | 34 | struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode); |
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) { |
c7cf0c68 | 51 | printk(KERN_ERR "jffs2_follow_link(): can't find symlink target\n"); |
2fb1e308 | 52 | p = ERR_PTR(-EIO); |
32f1a95d | 53 | } |
2b79adcc | 54 | D1(printk(KERN_DEBUG "jffs2_follow_link(): target path is '%s'\n", (char *) f->target)); |
32f1a95d | 55 | |
2fb1e308 | 56 | nd_set_link(nd, p); |
182ec4ee | 57 | |
32f1a95d | 58 | /* |
2b79adcc AB |
59 | * We will unlock the f->sem mutex but VFS will use the f->target string. This is safe |
60 | * since the only way that may cause f->target to be changed is iput() operation. | |
61 | * But VFS will not use f->target after iput() has been called. | |
32f1a95d | 62 | */ |
008b150a | 63 | return NULL; |
1da177e4 LT |
64 | } |
65 |