summaryrefslogtreecommitdiff
path: root/fs/ocfs2/symlink.c
blob: c6c94b55774f661ade4c88bdbbc2c00da8fdd26b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 *  linux/cluster/ssi/cfs/symlink.c
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License as
 *	published by the Free Software Foundation; either version 2 of
 *	the License, or (at your option) any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE
 *	or NON INFRINGEMENT.  See the GNU General Public License for more
 *	details.
 *
 * 	You should have received a copy of the GNU General Public License
 * 	along with this program; if not, write to the Free Software
 * 	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *	Questions/Comments/Bugfixes to ssic-linux-devel@lists.sourceforge.net
 *
 *  Copyright (C) 1992  Rick Sladkey
 *
 *  Optimization changes Copyright (C) 1994 Florian La Roche
 *
 *  Jun 7 1999, cache symlink lookups in the page cache.  -DaveM
 *
 *  Portions Copyright (C) 2001 Compaq Computer Corporation
 *
 *  ocfs2 symlink handling code.
 *
 *  Copyright (C) 2004, 2005 Oracle.
 *
 */

#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/utsname.h>

#define MLOG_MASK_PREFIX ML_NAMEI
#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "file.h"
#include "inode.h"
#include "journal.h"
#include "symlink.h"
#include "xattr.h"

#include "buffer_head_io.h"

static char *ocfs2_page_getlink(struct dentry * dentry,
				struct page **ppage);
static char *ocfs2_fast_symlink_getlink(struct inode *inode,
					struct buffer_head **bh);

/* get the link contents into pagecache */
static char *ocfs2_page_getlink(struct dentry * dentry,
				struct page **ppage)
{
	struct page * page;
	struct address_space *mapping = dentry->d_inode->i_mapping;
	page = read_mapping_page(mapping, 0, NULL);
	if (IS_ERR(page))
		goto sync_fail;
	*ppage = page;
	return kmap(page);

sync_fail:
	return (char*)page;
}

static char *ocfs2_fast_symlink_getlink(struct inode *inode,
					struct buffer_head **bh)
{
	int status;
	char *link = NULL;
	struct ocfs2_dinode *fe;

	mlog_entry_void();

	status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
				  OCFS2_I(inode)->ip_blkno,
				  bh,
				  OCFS2_BH_CACHED,
				  inode);
	if (status < 0) {
		mlog_errno(status);
		link = ERR_PTR(status);
		goto bail;
	}

	fe = (struct ocfs2_dinode *) (*bh)->b_data;
	link = (char *) fe->id2.i_symlink;
bail:
	mlog_exit(status);

	return link;
}

static int ocfs2_readlink(struct dentry *dentry,
			  char __user *buffer,
			  int buflen)
{
	int ret;
	char *link;
	struct buffer_head *bh = NULL;
	struct inode *inode = dentry->d_inode;

	mlog_entry_void();

	link = ocfs2_fast_symlink_getlink(inode, &bh);
	if (IS_ERR(link)) {
		ret = PTR_ERR(link);
		goto out;
	}

	/*
	 * Without vfsmount we can't update atime now,
	 * but we will update atime here ultimately.
	 */
	ret = vfs_readlink(dentry, buffer, buflen, link);

	brelse(bh);
out:
	mlog_exit(ret);
	return ret;
}

static void *ocfs2_follow_link(struct dentry *dentry,
			       struct nameidata *nd)
{
	int status;
	char *link;
	struct inode *inode = dentry->d_inode;
	struct page *page = NULL;
	struct buffer_head *bh = NULL;
	
	if (ocfs2_inode_is_fast_symlink(inode))
		link = ocfs2_fast_symlink_getlink(inode, &bh);
	else
		link = ocfs2_page_getlink(dentry, &page);
	if (IS_ERR(link)) {
		status = PTR_ERR(link);
		mlog_errno(status);
		goto bail;
	}

	status = vfs_follow_link(nd, link);

bail:
	if (page) {
		kunmap(page);
		page_cache_release(page);
	}
	brelse(bh);

	return ERR_PTR(status);
}

const struct inode_operations ocfs2_symlink_inode_operations = {
	.readlink	= page_readlink,
	.follow_link	= ocfs2_follow_link,
	.getattr	= ocfs2_getattr,
	.setattr	= ocfs2_setattr,
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr	= ocfs2_listxattr,
	.removexattr	= generic_removexattr,
};
const struct inode_operations ocfs2_fast_symlink_inode_operations = {
	.readlink	= ocfs2_readlink,
	.follow_link	= ocfs2_follow_link,
	.getattr	= ocfs2_getattr,
	.setattr	= ocfs2_setattr,
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr	= ocfs2_listxattr,
	.removexattr	= generic_removexattr,
};