Merge remote-tracking branch 'net/master'
[linux-2.6/next.git] / fs / ocfs2 / sysfile.c
blob3d635f4bbb201dba77cc79bd57feb67862744d4b
1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
4 * sysfile.c
6 * Initialize, read, write, etc. system files.
8 * Copyright (C) 2002, 2004 Oracle. All rights reserved.
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.
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.
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.
26 #include <linux/fs.h>
27 #include <linux/types.h>
28 #include <linux/highmem.h>
30 #include <cluster/masklog.h>
32 #include "ocfs2.h"
34 #include "alloc.h"
35 #include "dir.h"
36 #include "inode.h"
37 #include "journal.h"
38 #include "sysfile.h"
40 #include "buffer_head_io.h"
42 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
43 int type,
44 u32 slot);
46 #ifdef CONFIG_DEBUG_LOCK_ALLOC
47 static struct lock_class_key ocfs2_sysfile_cluster_lock_key[NUM_SYSTEM_INODES];
48 #endif
50 static inline int is_global_system_inode(int type)
52 return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
53 type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
56 static struct inode **get_local_system_inode(struct ocfs2_super *osb,
57 int type,
58 u32 slot)
60 int index;
61 struct inode **local_system_inodes, **free = NULL;
63 BUG_ON(slot == OCFS2_INVALID_SLOT);
64 BUG_ON(type < OCFS2_FIRST_LOCAL_SYSTEM_INODE ||
65 type > OCFS2_LAST_LOCAL_SYSTEM_INODE);
67 spin_lock(&osb->osb_lock);
68 local_system_inodes = osb->local_system_inodes;
69 spin_unlock(&osb->osb_lock);
71 if (unlikely(!local_system_inodes)) {
72 local_system_inodes = kzalloc(sizeof(struct inode *) *
73 NUM_LOCAL_SYSTEM_INODES *
74 osb->max_slots,
75 GFP_NOFS);
76 if (!local_system_inodes) {
77 mlog_errno(-ENOMEM);
79 * return NULL here so that ocfs2_get_sytem_file_inodes
80 * will try to create an inode and use it. We will try
81 * to initialize local_system_inodes next time.
83 return NULL;
86 spin_lock(&osb->osb_lock);
87 if (osb->local_system_inodes) {
88 /* Someone has initialized it for us. */
89 free = local_system_inodes;
90 local_system_inodes = osb->local_system_inodes;
91 } else
92 osb->local_system_inodes = local_system_inodes;
93 spin_unlock(&osb->osb_lock);
94 if (unlikely(free))
95 kfree(free);
98 index = (slot * NUM_LOCAL_SYSTEM_INODES) +
99 (type - OCFS2_FIRST_LOCAL_SYSTEM_INODE);
101 return &local_system_inodes[index];
104 struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
105 int type,
106 u32 slot)
108 struct inode *inode = NULL;
109 struct inode **arr = NULL;
111 /* avoid the lookup if cached in local system file array */
112 if (is_global_system_inode(type)) {
113 arr = &(osb->global_system_inodes[type]);
114 } else
115 arr = get_local_system_inode(osb, type, slot);
117 if (arr && ((inode = *arr) != NULL)) {
118 /* get a ref in addition to the array ref */
119 inode = igrab(inode);
120 BUG_ON(!inode);
122 return inode;
125 /* this gets one ref thru iget */
126 inode = _ocfs2_get_system_file_inode(osb, type, slot);
128 /* add one more if putting into array for first time */
129 if (arr && inode) {
130 *arr = igrab(inode);
131 BUG_ON(!*arr);
133 return inode;
136 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
137 int type,
138 u32 slot)
140 char namebuf[40];
141 struct inode *inode = NULL;
142 u64 blkno;
143 int status = 0;
145 ocfs2_sprintf_system_inode_name(namebuf,
146 sizeof(namebuf),
147 type, slot);
149 status = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
150 strlen(namebuf), &blkno);
151 if (status < 0) {
152 goto bail;
155 inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
156 if (IS_ERR(inode)) {
157 mlog_errno(PTR_ERR(inode));
158 inode = NULL;
159 goto bail;
161 #ifdef CONFIG_DEBUG_LOCK_ALLOC
162 if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
163 type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
164 type == JOURNAL_SYSTEM_INODE) {
165 /* Ignore inode lock on these inodes as the lock does not
166 * really belong to any process and lockdep cannot handle
167 * that */
168 OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
169 } else {
170 lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
171 l_lockdep_map,
172 ocfs2_system_inodes[type].si_name,
173 &ocfs2_sysfile_cluster_lock_key[type], 0);
175 #endif
176 bail:
178 return inode;