ia64/linux-2.6.18-xen.hg

view fs/ocfs2/symlink.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
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 */
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>
43 #define MLOG_MASK_PREFIX ML_NAMEI
44 #include <cluster/masklog.h>
46 #include "ocfs2.h"
48 #include "alloc.h"
49 #include "file.h"
50 #include "inode.h"
51 #include "journal.h"
52 #include "symlink.h"
54 #include "buffer_head_io.h"
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);
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_mapping_page(mapping, 0, NULL);
68 if (IS_ERR(page))
69 goto sync_fail;
70 wait_on_page_locked(page);
71 if (!PageUptodate(page))
72 goto async_fail;
73 *ppage = page;
74 return kmap(page);
76 async_fail:
77 page_cache_release(page);
78 return ERR_PTR(-EIO);
80 sync_fail:
81 return (char*)page;
82 }
84 static char *ocfs2_fast_symlink_getlink(struct inode *inode,
85 struct buffer_head **bh)
86 {
87 int status;
88 char *link = NULL;
89 struct ocfs2_dinode *fe;
91 mlog_entry_void();
93 status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
94 OCFS2_I(inode)->ip_blkno,
95 bh,
96 OCFS2_BH_CACHED,
97 inode);
98 if (status < 0) {
99 mlog_errno(status);
100 link = ERR_PTR(status);
101 goto bail;
102 }
104 fe = (struct ocfs2_dinode *) (*bh)->b_data;
105 link = (char *) fe->id2.i_symlink;
106 bail:
107 mlog_exit(status);
109 return link;
110 }
112 static int ocfs2_readlink(struct dentry *dentry,
113 char __user *buffer,
114 int buflen)
115 {
116 int ret;
117 char *link;
118 struct buffer_head *bh = NULL;
119 struct inode *inode = dentry->d_inode;
121 mlog_entry_void();
123 link = ocfs2_fast_symlink_getlink(inode, &bh);
124 if (IS_ERR(link)) {
125 ret = PTR_ERR(link);
126 goto out;
127 }
129 ret = vfs_readlink(dentry, buffer, buflen, link);
131 brelse(bh);
132 out:
133 mlog_exit(ret);
134 return ret;
135 }
137 static void *ocfs2_follow_link(struct dentry *dentry,
138 struct nameidata *nd)
139 {
140 int status;
141 char *link;
142 struct inode *inode = dentry->d_inode;
143 struct page *page = NULL;
144 struct buffer_head *bh = NULL;
146 if (ocfs2_inode_is_fast_symlink(inode))
147 link = ocfs2_fast_symlink_getlink(inode, &bh);
148 else
149 link = ocfs2_page_getlink(dentry, &page);
150 if (IS_ERR(link)) {
151 status = PTR_ERR(link);
152 mlog_errno(status);
153 goto bail;
154 }
156 status = vfs_follow_link(nd, link);
157 if (status && status != -ENOENT)
158 mlog_errno(status);
159 bail:
160 if (page) {
161 kunmap(page);
162 page_cache_release(page);
163 }
164 if (bh)
165 brelse(bh);
167 return ERR_PTR(status);
168 }
170 struct inode_operations ocfs2_symlink_inode_operations = {
171 .readlink = page_readlink,
172 .follow_link = ocfs2_follow_link,
173 .getattr = ocfs2_getattr,
174 };
175 struct inode_operations ocfs2_fast_symlink_inode_operations = {
176 .readlink = ocfs2_readlink,
177 .follow_link = ocfs2_follow_link,
178 .getattr = ocfs2_getattr,
179 };