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1 | /* -*- mode: c; c-basic-offset: 8; -*- |
2 | * vim: noexpandtab sw=8 ts=8 sts=0: | |
3 | * | |
4 | * linux/cluster/ssi/cfs/symlink.c | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License as | |
8 | * published by the Free Software Foundation; either version 2 of | |
9 | * the License, or (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE | |
14 | * or NON INFRINGEMENT. See the GNU General Public License for more | |
15 | * details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | * | |
21 | * Questions/Comments/Bugfixes to ssic-linux-devel@lists.sourceforge.net | |
22 | * | |
23 | * Copyright (C) 1992 Rick Sladkey | |
24 | * | |
25 | * Optimization changes Copyright (C) 1994 Florian La Roche | |
26 | * | |
27 | * Jun 7 1999, cache symlink lookups in the page cache. -DaveM | |
28 | * | |
29 | * Portions Copyright (C) 2001 Compaq Computer Corporation | |
30 | * | |
31 | * ocfs2 symlink handling code. | |
32 | * | |
33 | * Copyright (C) 2004, 2005 Oracle. | |
34 | * | |
35 | */ | |
36 | ||
37 | #include <linux/fs.h> | |
38 | #include <linux/types.h> | |
39 | #include <linux/slab.h> | |
40 | #include <linux/pagemap.h> | |
41 | #include <linux/utsname.h> | |
42 | ||
43 | #define MLOG_MASK_PREFIX ML_NAMEI | |
44 | #include <cluster/masklog.h> | |
45 | ||
46 | #include "ocfs2.h" | |
47 | ||
48 | #include "alloc.h" | |
49 | #include "file.h" | |
50 | #include "inode.h" | |
51 | #include "journal.h" | |
52 | #include "symlink.h" | |
53 | ||
54 | #include "buffer_head_io.h" | |
55 | ||
56 | static char *ocfs2_page_getlink(struct dentry * dentry, | |
57 | struct page **ppage); | |
58 | static char *ocfs2_fast_symlink_getlink(struct inode *inode, | |
59 | struct buffer_head **bh); | |
60 | ||
61 | /* get the link contents into pagecache */ | |
62 | static char *ocfs2_page_getlink(struct dentry * dentry, | |
63 | struct page **ppage) | |
64 | { | |
65 | struct page * page; | |
66 | struct address_space *mapping = dentry->d_inode->i_mapping; | |
67 | page = read_cache_page(mapping, 0, | |
68 | (filler_t *)mapping->a_ops->readpage, NULL); | |
69 | if (IS_ERR(page)) | |
70 | goto sync_fail; | |
71 | wait_on_page_locked(page); | |
72 | if (!PageUptodate(page)) | |
73 | goto async_fail; | |
74 | *ppage = page; | |
75 | return kmap(page); | |
76 | ||
77 | async_fail: | |
78 | page_cache_release(page); | |
79 | return ERR_PTR(-EIO); | |
80 | ||
81 | sync_fail: | |
82 | return (char*)page; | |
83 | } | |
84 | ||
85 | static char *ocfs2_fast_symlink_getlink(struct inode *inode, | |
86 | struct buffer_head **bh) | |
87 | { | |
88 | int status; | |
89 | char *link = NULL; | |
90 | struct ocfs2_dinode *fe; | |
91 | ||
92 | mlog_entry_void(); | |
93 | ||
94 | status = ocfs2_read_block(OCFS2_SB(inode->i_sb), | |
95 | OCFS2_I(inode)->ip_blkno, | |
96 | bh, | |
97 | OCFS2_BH_CACHED, | |
98 | inode); | |
99 | if (status < 0) { | |
100 | mlog_errno(status); | |
101 | link = ERR_PTR(status); | |
102 | goto bail; | |
103 | } | |
104 | ||
105 | fe = (struct ocfs2_dinode *) (*bh)->b_data; | |
106 | link = (char *) fe->id2.i_symlink; | |
107 | bail: | |
108 | mlog_exit(status); | |
109 | ||
110 | return link; | |
111 | } | |
112 | ||
113 | static int ocfs2_readlink(struct dentry *dentry, | |
114 | char __user *buffer, | |
115 | int buflen) | |
116 | { | |
117 | int ret; | |
118 | char *link; | |
119 | struct buffer_head *bh = NULL; | |
120 | struct inode *inode = dentry->d_inode; | |
121 | ||
122 | mlog_entry_void(); | |
123 | ||
124 | link = ocfs2_fast_symlink_getlink(inode, &bh); | |
125 | if (IS_ERR(link)) { | |
126 | ret = PTR_ERR(link); | |
127 | goto out; | |
128 | } | |
129 | ||
130 | ret = vfs_readlink(dentry, buffer, buflen, link); | |
131 | ||
132 | brelse(bh); | |
133 | out: | |
134 | mlog_exit(ret); | |
135 | return ret; | |
136 | } | |
137 | ||
138 | static void *ocfs2_follow_link(struct dentry *dentry, | |
139 | struct nameidata *nd) | |
140 | { | |
141 | int status; | |
142 | char *link; | |
143 | struct inode *inode = dentry->d_inode; | |
144 | struct page *page = NULL; | |
145 | struct buffer_head *bh = NULL; | |
146 | ||
147 | if (ocfs2_inode_is_fast_symlink(inode)) | |
148 | link = ocfs2_fast_symlink_getlink(inode, &bh); | |
149 | else | |
150 | link = ocfs2_page_getlink(dentry, &page); | |
151 | if (IS_ERR(link)) { | |
152 | status = PTR_ERR(link); | |
153 | mlog_errno(status); | |
154 | goto bail; | |
155 | } | |
156 | ||
157 | status = vfs_follow_link(nd, link); | |
158 | if (status) | |
159 | mlog_errno(status); | |
160 | bail: | |
161 | if (page) { | |
162 | kunmap(page); | |
163 | page_cache_release(page); | |
164 | } | |
165 | if (bh) | |
166 | brelse(bh); | |
167 | ||
168 | return ERR_PTR(status); | |
169 | } | |
170 | ||
171 | struct inode_operations ocfs2_symlink_inode_operations = { | |
172 | .readlink = page_readlink, | |
173 | .follow_link = ocfs2_follow_link, | |
174 | .getattr = ocfs2_getattr, | |
175 | }; | |
176 | struct inode_operations ocfs2_fast_symlink_inode_operations = { | |
177 | .readlink = ocfs2_readlink, | |
178 | .follow_link = ocfs2_follow_link, | |
179 | .getattr = ocfs2_getattr, | |
180 | }; |