fs/ocfs2/sysfile.c

   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 #define MLOG_MASK_PREFIX ML_INODE
  32 #include <cluster/masklog.h>
  33
  34 #include "ocfs2.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 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  54 static struct lock_class_key ocfs2_sysfile_cluster_lock_key[NUM_SYSTEM_INODES];
  55 #endif
  56
  57 static inline int is_global_system_inode(int type)
  58 {
  59         return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
  60                 type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
  61 }
  62
  63 static inline int is_in_system_inode_array(struct ocfs2_super *osb,
  64                                            int type,
  65                                            u32 slot)
  66 {
  67         return slot == osb->slot_num || is_global_system_inode(type);
  68 }
  69
  70 struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
  71                                           int type,
  72                                           u32 slot)
  73 {
  74         struct inode *inode = NULL;
  75         struct inode **arr = NULL;
  76
  77         /* avoid the lookup if cached in local system file array */
  78         if (is_in_system_inode_array(osb, type, slot))
  79                 arr = &(osb->system_inodes[type]);
  80
  81         if (arr && ((inode = *arr) != NULL)) {
  82                 /* get a ref in addition to the array ref */
  83                 inode = igrab(inode);
  84                 BUG_ON(!inode);
  85
  86                 return inode;
  87         }
  88
  89         /* this gets one ref thru iget */
  90         inode = _ocfs2_get_system_file_inode(osb, type, slot);
  91
  92         /* add one more if putting into array for first time */
  93         if (arr && inode) {
  94                 *arr = igrab(inode);
  95                 BUG_ON(!*arr);
  96         }
  97         return inode;
  98 }
  99
 100 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
 101                                                    int type,
 102                                                    u32 slot)
 103 {
 104         char namebuf[40];
 105         struct inode *inode = NULL;
 106         u64 blkno;
 107         int status = 0;
 108
 109         ocfs2_sprintf_system_inode_name(namebuf,
 110                                         sizeof(namebuf),
 111                                         type, slot);
 112
 113         status = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
 114                                             strlen(namebuf), &blkno);
 115         if (status < 0) {
 116                 goto bail;
 117         }
 118
 119         inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
 120         if (IS_ERR(inode)) {
 121                 mlog_errno(PTR_ERR(inode));
 122                 inode = NULL;
 123                 goto bail;
 124         }
 125 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 126         if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
 127             type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
 128             type == JOURNAL_SYSTEM_INODE) {
 129                 /* Ignore inode lock on these inodes as the lock does not
 130                  * really belong to any process and lockdep cannot handle
 131                  * that */
 132                 OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
 133         } else {
 134                 lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
 135                                                                 l_lockdep_map,
 136                                  ocfs2_system_inodes[type].si_name,
 137                                  &ocfs2_sysfile_cluster_lock_key[type], 0);
 138         }
 139 #endif
 140 bail:
 141
 142         return inode;
 143 }
 144