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 */
25
26 #include <linux/fs.h>
27 #include <linux/types.h>
28 #include <linux/highmem.h>
29
30 #include <cluster/masklog.h>
31
32 #include "ocfs2.h"
33
34 #include "alloc.h"
35 #include "dir.h"
36 #include "inode.h"
37 #include "journal.h"
38 #include "sysfile.h"
39
40 #include "buffer_head_io.h"
41
42 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
43 int type,
44 u32 slot);
45
46 #ifdef CONFIG_DEBUG_LOCK_ALLOC
47 static struct lock_class_key ocfs2_sysfile_cluster_lock_key[NUM_SYSTEM_INODES];
48 #endif
49
is_global_system_inode(int type)50 static inline int is_global_system_inode(int type)
51 {
52 return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
53 type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
54 }
55
get_local_system_inode(struct ocfs2_super * osb,int type,u32 slot)56 static struct inode **get_local_system_inode(struct ocfs2_super *osb,
57 int type,
58 u32 slot)
59 {
60 int index;
61 struct inode **local_system_inodes, **free = NULL;
62
63 BUG_ON(slot == OCFS2_INVALID_SLOT);
64 BUG_ON(type < OCFS2_FIRST_LOCAL_SYSTEM_INODE ||
65 type > OCFS2_LAST_LOCAL_SYSTEM_INODE);
66
67 spin_lock(&osb->osb_lock);
68 local_system_inodes = osb->local_system_inodes;
69 spin_unlock(&osb->osb_lock);
70
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);
78 /*
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.
82 */
83 return NULL;
84 }
85
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 kfree(free);
95 }
96
97 index = (slot * NUM_LOCAL_SYSTEM_INODES) +
98 (type - OCFS2_FIRST_LOCAL_SYSTEM_INODE);
99
100 return &local_system_inodes[index];
101 }
102
ocfs2_get_system_file_inode(struct ocfs2_super * osb,int type,u32 slot)103 struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
104 int type,
105 u32 slot)
106 {
107 struct inode *inode = NULL;
108 struct inode **arr = NULL;
109
110 /* avoid the lookup if cached in local system file array */
111 if (is_global_system_inode(type)) {
112 arr = &(osb->global_system_inodes[type]);
113 } else
114 arr = get_local_system_inode(osb, type, slot);
115
116 mutex_lock(&osb->system_file_mutex);
117 if (arr && ((inode = *arr) != NULL)) {
118 /* get a ref in addition to the array ref */
119 inode = igrab(inode);
120 mutex_unlock(&osb->system_file_mutex);
121 BUG_ON(!inode);
122
123 return inode;
124 }
125
126 /* this gets one ref thru iget */
127 inode = _ocfs2_get_system_file_inode(osb, type, slot);
128
129 /* add one more if putting into array for first time */
130 if (arr && inode) {
131 *arr = igrab(inode);
132 BUG_ON(!*arr);
133 }
134 mutex_unlock(&osb->system_file_mutex);
135 return inode;
136 }
137
_ocfs2_get_system_file_inode(struct ocfs2_super * osb,int type,u32 slot)138 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
139 int type,
140 u32 slot)
141 {
142 char namebuf[40];
143 struct inode *inode = NULL;
144 u64 blkno;
145 int status = 0;
146
147 ocfs2_sprintf_system_inode_name(namebuf,
148 sizeof(namebuf),
149 type, slot);
150
151 status = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
152 strlen(namebuf), &blkno);
153 if (status < 0) {
154 goto bail;
155 }
156
157 inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
158 if (IS_ERR(inode)) {
159 mlog_errno(PTR_ERR(inode));
160 inode = NULL;
161 goto bail;
162 }
163 #ifdef CONFIG_DEBUG_LOCK_ALLOC
164 if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
165 type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
166 type == JOURNAL_SYSTEM_INODE) {
167 /* Ignore inode lock on these inodes as the lock does not
168 * really belong to any process and lockdep cannot handle
169 * that */
170 OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
171 } else {
172 lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
173 l_lockdep_map,
174 ocfs2_system_inodes[type].si_name,
175 &ocfs2_sysfile_cluster_lock_key[type], 0);
176 }
177 #endif
178 bail:
179
180 return inode;
181 }
182
183