summaryrefslogtreecommitdiff
path: root/ANDROID_3.4.5/fs/ocfs2/sysfile.c
blob: 3d635f4bbb201dba77cc79bd57feb67862744d4b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * sysfile.c
 *
 * Initialize, read, write, etc. system files.
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/fs.h>
#include <linux/types.h>
#include <linux/highmem.h>

#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "dir.h"
#include "inode.h"
#include "journal.h"
#include "sysfile.h"

#include "buffer_head_io.h"

static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
						   int type,
						   u32 slot);

#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key ocfs2_sysfile_cluster_lock_key[NUM_SYSTEM_INODES];
#endif

static inline int is_global_system_inode(int type)
{
	return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
		type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
}

static struct inode **get_local_system_inode(struct ocfs2_super *osb,
					     int type,
					     u32 slot)
{
	int index;
	struct inode **local_system_inodes, **free = NULL;

	BUG_ON(slot == OCFS2_INVALID_SLOT);
	BUG_ON(type < OCFS2_FIRST_LOCAL_SYSTEM_INODE ||
	       type > OCFS2_LAST_LOCAL_SYSTEM_INODE);

	spin_lock(&osb->osb_lock);
	local_system_inodes = osb->local_system_inodes;
	spin_unlock(&osb->osb_lock);

	if (unlikely(!local_system_inodes)) {
		local_system_inodes = kzalloc(sizeof(struct inode *) *
					      NUM_LOCAL_SYSTEM_INODES *
					      osb->max_slots,
					      GFP_NOFS);
		if (!local_system_inodes) {
			mlog_errno(-ENOMEM);
			/*
			 * return NULL here so that ocfs2_get_sytem_file_inodes
			 * will try to create an inode and use it. We will try
			 * to initialize local_system_inodes next time.
			 */
			return NULL;
		}

		spin_lock(&osb->osb_lock);
		if (osb->local_system_inodes) {
			/* Someone has initialized it for us. */
			free = local_system_inodes;
			local_system_inodes = osb->local_system_inodes;
		} else
			osb->local_system_inodes = local_system_inodes;
		spin_unlock(&osb->osb_lock);
		if (unlikely(free))
			kfree(free);
	}

	index = (slot * NUM_LOCAL_SYSTEM_INODES) +
		(type - OCFS2_FIRST_LOCAL_SYSTEM_INODE);

	return &local_system_inodes[index];
}

struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
					  int type,
					  u32 slot)
{
	struct inode *inode = NULL;
	struct inode **arr = NULL;

	/* avoid the lookup if cached in local system file array */
	if (is_global_system_inode(type)) {
		arr = &(osb->global_system_inodes[type]);
	} else
		arr = get_local_system_inode(osb, type, slot);

	if (arr && ((inode = *arr) != NULL)) {
		/* get a ref in addition to the array ref */
		inode = igrab(inode);
		BUG_ON(!inode);

		return inode;
	}

	/* this gets one ref thru iget */
	inode = _ocfs2_get_system_file_inode(osb, type, slot);

	/* add one more if putting into array for first time */
	if (arr && inode) {
		*arr = igrab(inode);
		BUG_ON(!*arr);
	}
	return inode;
}

static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
						   int type,
						   u32 slot)
{
	char namebuf[40];
	struct inode *inode = NULL;
	u64 blkno;
	int status = 0;

	ocfs2_sprintf_system_inode_name(namebuf,
					sizeof(namebuf),
					type, slot);

	status = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
					    strlen(namebuf), &blkno);
	if (status < 0) {
		goto bail;
	}

	inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
	if (IS_ERR(inode)) {
		mlog_errno(PTR_ERR(inode));
		inode = NULL;
		goto bail;
	}
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
	    type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
	    type == JOURNAL_SYSTEM_INODE) {
		/* Ignore inode lock on these inodes as the lock does not
		 * really belong to any process and lockdep cannot handle
		 * that */
		OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
	} else {
		lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
								l_lockdep_map,
				 ocfs2_system_inodes[type].si_name,
				 &ocfs2_sysfile_cluster_lock_key[type], 0);
	}
#endif
bail:

	return inode;
}