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/slab.h> 29 #include <linux/highmem.h> 30 31 #include "ocfs2.h" 32 33 #define MLOG_MASK_PREFIX ML_INODE 34 #include <cluster/masklog.h> 35 36 #include "alloc.h" 37 #include "dir.h" 38 #include "inode.h" 39 #include "journal.h" 40 #include "sysfile.h" 41 42 #include "buffer_head_io.h" 43 44 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb, 45 int type, 46 u32 slot); 47 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); 52 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 } 58 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 } 65 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; 72 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]); 76 77 if (arr && ((inode = *arr) != NULL)) { 78 /* get a ref in addition to the array ref */ 79 inode = igrab(inode); 80 if (!inode) 81 BUG(); 82 83 return inode; 84 } 85 86 /* this gets one ref thru iget */ 87 inode = _ocfs2_get_system_file_inode(osb, type, slot); 88 89 /* add one more if putting into array for first time */ 90 if (arr && inode) { 91 *arr = igrab(inode); 92 if (!*arr) 93 BUG(); 94 } 95 return inode; 96 } 97 98 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb, 99 int type, 100 u32 slot) 101 { 102 char namebuf[40]; 103 struct inode *inode = NULL; 104 u64 blkno; 105 struct buffer_head *dirent_bh = NULL; 106 struct ocfs2_dir_entry *de = NULL; 107 int status = 0; 108 109 ocfs2_sprintf_system_inode_name(namebuf, 110 sizeof(namebuf), 111 type, slot); 112 113 status = ocfs2_find_files_on_disk(namebuf, strlen(namebuf), 114 &blkno, osb->sys_root_inode, 115 &dirent_bh, &de); 116 if (status < 0) { 117 goto bail; 118 } 119 120 inode = ocfs2_iget(osb, blkno); 121 if (IS_ERR(inode)) { 122 mlog_errno(PTR_ERR(inode)); 123 inode = NULL; 124 goto bail; 125 } 126 bail: 127 if (dirent_bh) 128 brelse(dirent_bh); 129 return inode; 130 } 131 132