ia64/linux-2.6.18-xen.hg

view fs/ocfs2/sysfile.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 * sysfile.c
5 *
6 * Initialize, read, write, etc. system files.
7 *
8 * Copyright (C) 2002, 2004 Oracle. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 */
26 #include <linux/fs.h>
27 #include <linux/types.h>
28 #include <linux/slab.h>
29 #include <linux/highmem.h>
31 #include "ocfs2.h"
33 #define MLOG_MASK_PREFIX ML_INODE
34 #include <cluster/masklog.h>
36 #include "alloc.h"
37 #include "dir.h"
38 #include "inode.h"
39 #include "journal.h"
40 #include "sysfile.h"
42 #include "buffer_head_io.h"
44 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
45 int type,
46 u32 slot);
48 static inline int is_global_system_inode(int type);
49 static inline int is_in_system_inode_array(struct ocfs2_super *osb,
50 int type,
51 u32 slot);
53 static inline int is_global_system_inode(int type)
54 {
55 return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
56 type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
57 }
59 static inline int is_in_system_inode_array(struct ocfs2_super *osb,
60 int type,
61 u32 slot)
62 {
63 return slot == osb->slot_num || is_global_system_inode(type);
64 }
66 struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
67 int type,
68 u32 slot)
69 {
70 struct inode *inode = NULL;
71 struct inode **arr = NULL;
73 /* avoid the lookup if cached in local system file array */
74 if (is_in_system_inode_array(osb, type, slot))
75 arr = &(osb->system_inodes[type]);
77 if (arr && ((inode = *arr) != NULL)) {
78 /* get a ref in addition to the array ref */
79 inode = igrab(inode);
80 BUG_ON(!inode);
82 return inode;
83 }
85 /* this gets one ref thru iget */
86 inode = _ocfs2_get_system_file_inode(osb, type, slot);
88 /* add one more if putting into array for first time */
89 if (arr && inode) {
90 *arr = igrab(inode);
91 BUG_ON(!*arr);
92 }
93 return inode;
94 }
96 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
97 int type,
98 u32 slot)
99 {
100 char namebuf[40];
101 struct inode *inode = NULL;
102 u64 blkno;
103 struct buffer_head *dirent_bh = NULL;
104 struct ocfs2_dir_entry *de = NULL;
105 int status = 0;
107 ocfs2_sprintf_system_inode_name(namebuf,
108 sizeof(namebuf),
109 type, slot);
111 status = ocfs2_find_files_on_disk(namebuf, strlen(namebuf),
112 &blkno, osb->sys_root_inode,
113 &dirent_bh, &de);
114 if (status < 0) {
115 goto bail;
116 }
118 inode = ocfs2_iget(osb, blkno);
119 if (IS_ERR(inode)) {
120 mlog_errno(PTR_ERR(inode));
121 inode = NULL;
122 goto bail;
123 }
124 bail:
125 if (dirent_bh)
126 brelse(dirent_bh);
127 return inode;
128 }