xref: /linux/fs/ocfs2/sysfile.c (revision f5b1910e23f1233c8d4185268b2e659df2bc5dbf)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * sysfile.c
4  *
5  * Initialize, read, write, etc. system files.
6  *
7  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
8  */
9 
10 #include <linux/fs.h>
11 #include <linux/types.h>
12 #include <linux/highmem.h>
13 
14 #include <cluster/masklog.h>
15 
16 #include "ocfs2.h"
17 
18 #include "alloc.h"
19 #include "dir.h"
20 #include "inode.h"
21 #include "journal.h"
22 #include "sysfile.h"
23 
24 #include "buffer_head_io.h"
25 
26 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
27 						   int type,
28 						   u32 slot);
29 
30 #ifdef CONFIG_DEBUG_LOCK_ALLOC
31 static struct lock_class_key ocfs2_sysfile_cluster_lock_key[NUM_SYSTEM_INODES];
32 #endif
33 
34 static inline int is_global_system_inode(int type)
35 {
36 	return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
37 		type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
38 }
39 
40 static struct inode **get_local_system_inode(struct ocfs2_super *osb,
41 					     int type,
42 					     u32 slot)
43 {
44 	int index;
45 	struct inode **local_system_inodes, **free = NULL;
46 
47 	BUG_ON(slot == OCFS2_INVALID_SLOT);
48 	BUG_ON(type < OCFS2_FIRST_LOCAL_SYSTEM_INODE ||
49 	       type > OCFS2_LAST_LOCAL_SYSTEM_INODE);
50 
51 	spin_lock(&osb->osb_lock);
52 	local_system_inodes = osb->local_system_inodes;
53 	spin_unlock(&osb->osb_lock);
54 
55 	if (unlikely(!local_system_inodes)) {
56 		local_system_inodes =
57 			kzalloc(array3_size(sizeof(struct inode *),
58 					    NUM_LOCAL_SYSTEM_INODES,
59 					    osb->max_slots),
60 				GFP_NOFS);
61 		if (!local_system_inodes) {
62 			mlog_errno(-ENOMEM);
63 			/*
64 			 * return NULL here so that ocfs2_get_sytem_file_inodes
65 			 * will try to create an inode and use it. We will try
66 			 * to initialize local_system_inodes next time.
67 			 */
68 			return NULL;
69 		}
70 
71 		spin_lock(&osb->osb_lock);
72 		if (osb->local_system_inodes) {
73 			/* Someone has initialized it for us. */
74 			free = local_system_inodes;
75 			local_system_inodes = osb->local_system_inodes;
76 		} else
77 			osb->local_system_inodes = local_system_inodes;
78 		spin_unlock(&osb->osb_lock);
79 		kfree(free);
80 	}
81 
82 	index = (slot * NUM_LOCAL_SYSTEM_INODES) +
83 		(type - OCFS2_FIRST_LOCAL_SYSTEM_INODE);
84 
85 	return &local_system_inodes[index];
86 }
87 
88 struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
89 					  int type,
90 					  u32 slot)
91 {
92 	struct inode *inode = NULL;
93 	struct inode **arr = NULL;
94 
95 	/* avoid the lookup if cached in local system file array */
96 	if (is_global_system_inode(type)) {
97 		arr = &(osb->global_system_inodes[type]);
98 	} else
99 		arr = get_local_system_inode(osb, type, slot);
100 
101 	if (arr && ((inode = *arr) != NULL)) {
102 		/* get a ref in addition to the array ref */
103 		inode = igrab(inode);
104 		BUG_ON(!inode);
105 
106 		return inode;
107 	}
108 
109 	/* this gets one ref thru iget */
110 	inode = _ocfs2_get_system_file_inode(osb, type, slot);
111 
112 	/* add one more if putting into array for first time */
113 	if (inode && arr && !*arr && !cmpxchg(&(*arr), NULL, inode)) {
114 		inode = igrab(inode);
115 		BUG_ON(!inode);
116 	}
117 	return inode;
118 }
119 
120 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
121 						   int type,
122 						   u32 slot)
123 {
124 	char namebuf[40];
125 	struct inode *inode = NULL;
126 	u64 blkno;
127 	int len, status = 0;
128 
129 	len = ocfs2_sprintf_system_inode_name(namebuf,
130 					      sizeof(namebuf),
131 					      type, slot);
132 
133 	status = ocfs2_lookup_ino_from_name(osb->sys_root_inode,
134 					    namebuf, len, &blkno);
135 	if (status < 0) {
136 		goto bail;
137 	}
138 
139 	inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
140 	if (IS_ERR(inode)) {
141 		mlog_errno(PTR_ERR(inode));
142 		inode = NULL;
143 		goto bail;
144 	}
145 #ifdef CONFIG_DEBUG_LOCK_ALLOC
146 	if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
147 	    type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
148 	    type == JOURNAL_SYSTEM_INODE) {
149 		/* Ignore inode lock on these inodes as the lock does not
150 		 * really belong to any process and lockdep cannot handle
151 		 * that */
152 		OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
153 	} else {
154 		lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
155 								l_lockdep_map,
156 				 ocfs2_system_inodes[type].si_name,
157 				 &ocfs2_sysfile_cluster_lock_key[type], 0);
158 	}
159 #endif
160 bail:
161 
162 	return inode;
163 }
164 
165