Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/nfs/symlink.c | |
4 | * | |
5 | * Copyright (C) 1992 Rick Sladkey | |
6 | * | |
7 | * Optimization changes Copyright (C) 1994 Florian La Roche | |
8 | * | |
9 | * Jun 7 1999, cache symlink lookups in the page cache. -DaveM | |
10 | * | |
11 | * nfs symlink handling code | |
12 | */ | |
13 | ||
1da177e4 LT |
14 | #include <linux/time.h> |
15 | #include <linux/errno.h> | |
16 | #include <linux/sunrpc/clnt.h> | |
17 | #include <linux/nfs.h> | |
18 | #include <linux/nfs2.h> | |
19 | #include <linux/nfs_fs.h> | |
20 | #include <linux/pagemap.h> | |
21 | #include <linux/stat.h> | |
22 | #include <linux/mm.h> | |
1da177e4 | 23 | #include <linux/string.h> |
1da177e4 LT |
24 | |
25 | /* Symlink caching in the page cache is even more simplistic | |
26 | * and straight-forward than readdir caching. | |
1da177e4 LT |
27 | */ |
28 | ||
a46126cc | 29 | static int nfs_symlink_filler(void *data, struct page *page) |
1da177e4 | 30 | { |
a46126cc | 31 | struct inode *inode = data; |
1da177e4 LT |
32 | int error; |
33 | ||
cc314eef | 34 | error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE); |
1da177e4 LT |
35 | if (error < 0) |
36 | goto error; | |
37 | SetPageUptodate(page); | |
38 | unlock_page(page); | |
39 | return 0; | |
40 | ||
41 | error: | |
42 | SetPageError(page); | |
43 | unlock_page(page); | |
44 | return -EIO; | |
45 | } | |
46 | ||
6b255391 | 47 | static const char *nfs_get_link(struct dentry *dentry, |
fceef393 AV |
48 | struct inode *inode, |
49 | struct delayed_call *done) | |
1da177e4 | 50 | { |
1da177e4 | 51 | struct page *page; |
717d44e8 TM |
52 | void *err; |
53 | ||
0d0def49 AV |
54 | if (!dentry) { |
55 | err = ERR_PTR(nfs_revalidate_mapping_rcu(inode)); | |
56 | if (err) | |
57 | return err; | |
58 | page = find_get_page(inode->i_mapping, 0); | |
59 | if (!page) | |
60 | return ERR_PTR(-ECHILD); | |
61 | if (!PageUptodate(page)) { | |
62 | put_page(page); | |
63 | return ERR_PTR(-ECHILD); | |
64 | } | |
65 | } else { | |
66 | err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping)); | |
67 | if (err) | |
68 | return err; | |
a46126cc CH |
69 | page = read_cache_page(&inode->i_data, 0, nfs_symlink_filler, |
70 | inode); | |
0d0def49 AV |
71 | if (IS_ERR(page)) |
72 | return ERR_CAST(page); | |
73 | } | |
fceef393 | 74 | set_delayed_call(done, page_put_link, page); |
21fc61c7 | 75 | return page_address(page); |
1da177e4 LT |
76 | } |
77 | ||
1da177e4 LT |
78 | /* |
79 | * symlinks can't do much... | |
80 | */ | |
92e1d5be | 81 | const struct inode_operations nfs_symlink_inode_operations = { |
6b255391 | 82 | .get_link = nfs_get_link, |
1da177e4 LT |
83 | .getattr = nfs_getattr, |
84 | .setattr = nfs_setattr, | |
85 | }; |