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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/nfs/symlink.c | |
3 | * | |
4 | * Copyright (C) 1992 Rick Sladkey | |
5 | * | |
6 | * Optimization changes Copyright (C) 1994 Florian La Roche | |
7 | * | |
8 | * Jun 7 1999, cache symlink lookups in the page cache. -DaveM | |
9 | * | |
10 | * nfs symlink handling code | |
11 | */ | |
12 | ||
13 | #define NFS_NEED_XDR_TYPES | |
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> | |
23 | #include <linux/slab.h> | |
24 | #include <linux/string.h> | |
25 | #include <linux/smp_lock.h> | |
26 | #include <linux/namei.h> | |
27 | ||
28 | /* Symlink caching in the page cache is even more simplistic | |
29 | * and straight-forward than readdir caching. | |
1da177e4 LT |
30 | */ |
31 | ||
1da177e4 LT |
32 | static int nfs_symlink_filler(struct inode *inode, struct page *page) |
33 | { | |
1da177e4 LT |
34 | int error; |
35 | ||
cc314eef | 36 | error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE); |
1da177e4 LT |
37 | if (error < 0) |
38 | goto error; | |
39 | SetPageUptodate(page); | |
40 | unlock_page(page); | |
41 | return 0; | |
42 | ||
43 | error: | |
44 | SetPageError(page); | |
45 | unlock_page(page); | |
46 | return -EIO; | |
47 | } | |
48 | ||
cc314eef | 49 | static void *nfs_follow_link(struct dentry *dentry, struct nameidata *nd) |
1da177e4 LT |
50 | { |
51 | struct inode *inode = dentry->d_inode; | |
52 | struct page *page; | |
717d44e8 TM |
53 | void *err; |
54 | ||
55 | err = ERR_PTR(nfs_revalidate_mapping_nolock(inode, inode->i_mapping)); | |
1da177e4 LT |
56 | if (err) |
57 | goto read_failed; | |
58 | page = read_cache_page(&inode->i_data, 0, | |
59 | (filler_t *)nfs_symlink_filler, inode); | |
60 | if (IS_ERR(page)) { | |
61 | err = page; | |
62 | goto read_failed; | |
63 | } | |
64 | if (!PageUptodate(page)) { | |
65 | err = ERR_PTR(-EIO); | |
66 | goto getlink_read_error; | |
67 | } | |
cc314eef LT |
68 | nd_set_link(nd, kmap(page)); |
69 | return page; | |
1da177e4 LT |
70 | |
71 | getlink_read_error: | |
72 | page_cache_release(page); | |
73 | read_failed: | |
74 | nd_set_link(nd, err); | |
cc314eef | 75 | return NULL; |
1da177e4 LT |
76 | } |
77 | ||
1da177e4 LT |
78 | /* |
79 | * symlinks can't do much... | |
80 | */ | |
92e1d5be | 81 | const struct inode_operations nfs_symlink_inode_operations = { |
1da177e4 LT |
82 | .readlink = generic_readlink, |
83 | .follow_link = nfs_follow_link, | |
9bf2aa12 | 84 | .put_link = page_put_link, |
1da177e4 LT |
85 | .getattr = nfs_getattr, |
86 | .setattr = nfs_setattr, | |
87 | }; |