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/namei.h>
42
43 #include <cluster/masklog.h>
44
45 #include "ocfs2.h"
46
47 #include "alloc.h"
48 #include "file.h"
49 #include "inode.h"
50 #include "journal.h"
51 #include "symlink.h"
52 #include "xattr.h"
53
54 #include "buffer_head_io.h"
55
56
ocfs2_fast_symlink_getlink(struct inode * inode,struct buffer_head ** bh)57 static char *ocfs2_fast_symlink_getlink(struct inode *inode,
58 struct buffer_head **bh)
59 {
60 int status;
61 char *link = NULL;
62 struct ocfs2_dinode *fe;
63
64 status = ocfs2_read_inode_block(inode, bh);
65 if (status < 0) {
66 mlog_errno(status);
67 link = ERR_PTR(status);
68 goto bail;
69 }
70
71 fe = (struct ocfs2_dinode *) (*bh)->b_data;
72 link = (char *) fe->id2.i_symlink;
73 bail:
74
75 return link;
76 }
77
ocfs2_readlink(struct dentry * dentry,char __user * buffer,int buflen)78 static int ocfs2_readlink(struct dentry *dentry,
79 char __user *buffer,
80 int buflen)
81 {
82 int ret;
83 char *link;
84 struct buffer_head *bh = NULL;
85 struct inode *inode = dentry->d_inode;
86
87 link = ocfs2_fast_symlink_getlink(inode, &bh);
88 if (IS_ERR(link)) {
89 ret = PTR_ERR(link);
90 goto out;
91 }
92
93 /*
94 * Without vfsmount we can't update atime now,
95 * but we will update atime here ultimately.
96 */
97 ret = vfs_readlink(dentry, buffer, buflen, link);
98
99 brelse(bh);
100 out:
101 if (ret < 0)
102 mlog_errno(ret);
103 return ret;
104 }
105
ocfs2_fast_follow_link(struct dentry * dentry,struct nameidata * nd)106 static void *ocfs2_fast_follow_link(struct dentry *dentry,
107 struct nameidata *nd)
108 {
109 int status = 0;
110 int len;
111 char *target, *link = ERR_PTR(-ENOMEM);
112 struct inode *inode = dentry->d_inode;
113 struct buffer_head *bh = NULL;
114
115 BUG_ON(!ocfs2_inode_is_fast_symlink(inode));
116 target = ocfs2_fast_symlink_getlink(inode, &bh);
117 if (IS_ERR(target)) {
118 status = PTR_ERR(target);
119 mlog_errno(status);
120 goto bail;
121 }
122
123 /* Fast symlinks can't be large */
124 len = strnlen(target, ocfs2_fast_symlink_chars(inode->i_sb));
125 link = kzalloc(len + 1, GFP_NOFS);
126 if (!link) {
127 status = -ENOMEM;
128 mlog_errno(status);
129 goto bail;
130 }
131
132 memcpy(link, target, len);
133
134 bail:
135 nd_set_link(nd, status ? ERR_PTR(status) : link);
136 brelse(bh);
137
138 if (status)
139 mlog_errno(status);
140 return NULL;
141 }
142
ocfs2_fast_put_link(struct dentry * dentry,struct nameidata * nd,void * cookie)143 static void ocfs2_fast_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
144 {
145 char *link = nd_get_link(nd);
146 if (!IS_ERR(link))
147 kfree(link);
148 }
149
150 const struct inode_operations ocfs2_symlink_inode_operations = {
151 .readlink = page_readlink,
152 .follow_link = page_follow_link_light,
153 .put_link = page_put_link,
154 .getattr = ocfs2_getattr,
155 .setattr = ocfs2_setattr,
156 .setxattr = generic_setxattr,
157 .getxattr = generic_getxattr,
158 .listxattr = ocfs2_listxattr,
159 .removexattr = generic_removexattr,
160 .fiemap = ocfs2_fiemap,
161 };
162 const struct inode_operations ocfs2_fast_symlink_inode_operations = {
163 .readlink = ocfs2_readlink,
164 .follow_link = ocfs2_fast_follow_link,
165 .put_link = ocfs2_fast_put_link,
166 .getattr = ocfs2_getattr,
167 .setattr = ocfs2_setattr,
168 .setxattr = generic_setxattr,
169 .getxattr = generic_getxattr,
170 .listxattr = ocfs2_listxattr,
171 .removexattr = generic_removexattr,
172 .fiemap = ocfs2_fiemap,
173 };
174