Root/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/highmem.h>
29
30#define MLOG_MASK_PREFIX ML_INODE
31#include <cluster/masklog.h>
32
33#include "ocfs2.h"
34
35#include "alloc.h"
36#include "dir.h"
37#include "inode.h"
38#include "journal.h"
39#include "sysfile.h"
40
41#include "buffer_head_io.h"
42
43static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
44                           int type,
45                           u32 slot);
46
47static inline int is_global_system_inode(int type);
48static inline int is_in_system_inode_array(struct ocfs2_super *osb,
49                       int type,
50                       u32 slot);
51
52#ifdef CONFIG_DEBUG_LOCK_ALLOC
53static struct lock_class_key ocfs2_sysfile_cluster_lock_key[NUM_SYSTEM_INODES];
54#endif
55
56static inline int is_global_system_inode(int type)
57{
58    return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
59        type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
60}
61
62static inline int is_in_system_inode_array(struct ocfs2_super *osb,
63                       int type,
64                       u32 slot)
65{
66    return slot == osb->slot_num || is_global_system_inode(type);
67}
68
69struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
70                      int type,
71                      u32 slot)
72{
73    struct inode *inode = NULL;
74    struct inode **arr = NULL;
75
76    /* avoid the lookup if cached in local system file array */
77    if (is_in_system_inode_array(osb, type, slot))
78        arr = &(osb->system_inodes[type]);
79
80    if (arr && ((inode = *arr) != NULL)) {
81        /* get a ref in addition to the array ref */
82        inode = igrab(inode);
83        BUG_ON(!inode);
84
85        return inode;
86    }
87
88    /* this gets one ref thru iget */
89    inode = _ocfs2_get_system_file_inode(osb, type, slot);
90
91    /* add one more if putting into array for first time */
92    if (arr && inode) {
93        *arr = igrab(inode);
94        BUG_ON(!*arr);
95    }
96    return inode;
97}
98
99static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
100                           int type,
101                           u32 slot)
102{
103    char namebuf[40];
104    struct inode *inode = NULL;
105    u64 blkno;
106    int status = 0;
107
108    ocfs2_sprintf_system_inode_name(namebuf,
109                    sizeof(namebuf),
110                    type, slot);
111
112    status = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
113                        strlen(namebuf), &blkno);
114    if (status < 0) {
115        goto bail;
116    }
117
118    inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
119    if (IS_ERR(inode)) {
120        mlog_errno(PTR_ERR(inode));
121        inode = NULL;
122        goto bail;
123    }
124#ifdef CONFIG_DEBUG_LOCK_ALLOC
125    if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
126        type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
127        type == JOURNAL_SYSTEM_INODE) {
128        /* Ignore inode lock on these inodes as the lock does not
129         * really belong to any process and lockdep cannot handle
130         * that */
131        OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
132    } else {
133        lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
134                                l_lockdep_map,
135                 ocfs2_system_inodes[type].si_name,
136                 &ocfs2_sysfile_cluster_lock_key[type], 0);
137    }
138#endif
139bail:
140
141    return inode;
142}
143
144

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