xref: /openbmc/linux/fs/ocfs2/sysfile.c (revision cb25797d451dc774d9dbc402a65f16a0e32199fe)
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 static struct lock_class_key ocfs2_sysfile_cluster_lock_key[NUM_SYSTEM_INODES];
54 
55 static inline int is_global_system_inode(int type)
56 {
57 	return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
58 		type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
59 }
60 
61 static inline int is_in_system_inode_array(struct ocfs2_super *osb,
62 					   int type,
63 					   u32 slot)
64 {
65 	return slot == osb->slot_num || is_global_system_inode(type);
66 }
67 
68 struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
69 					  int type,
70 					  u32 slot)
71 {
72 	struct inode *inode = NULL;
73 	struct inode **arr = NULL;
74 
75 	/* avoid the lookup if cached in local system file array */
76 	if (is_in_system_inode_array(osb, type, slot))
77 		arr = &(osb->system_inodes[type]);
78 
79 	if (arr && ((inode = *arr) != NULL)) {
80 		/* get a ref in addition to the array ref */
81 		inode = igrab(inode);
82 		BUG_ON(!inode);
83 
84 		return inode;
85 	}
86 
87 	/* this gets one ref thru iget */
88 	inode = _ocfs2_get_system_file_inode(osb, type, slot);
89 
90 	/* add one more if putting into array for first time */
91 	if (arr && inode) {
92 		*arr = igrab(inode);
93 		BUG_ON(!*arr);
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 	int status = 0;
106 
107 	ocfs2_sprintf_system_inode_name(namebuf,
108 					sizeof(namebuf),
109 					type, slot);
110 
111 	status = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
112 					    strlen(namebuf), &blkno);
113 	if (status < 0) {
114 		goto bail;
115 	}
116 
117 	inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
118 	if (IS_ERR(inode)) {
119 		mlog_errno(PTR_ERR(inode));
120 		inode = NULL;
121 		goto bail;
122 	}
123 #ifdef CONFIG_DEBUG_LOCK_ALLOC
124 	if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
125 	    type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
126 	    type == JOURNAL_SYSTEM_INODE) {
127 		/* Ignore inode lock on these inodes as the lock does not
128 		 * really belong to any process and lockdep cannot handle
129 		 * that */
130 		OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
131 	} else {
132 		lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
133 								l_lockdep_map,
134 				 ocfs2_system_inodes[type].si_name,
135 				 &ocfs2_sysfile_cluster_lock_key[type], 0);
136 	}
137 #endif
138 bail:
139 
140 	return inode;
141 }
142 
143