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 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 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 } 102 103 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 } 137 138 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