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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 
is_global_system_inode(int type)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 
get_local_system_inode(struct ocfs2_super * osb,int type,u32 slot)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 
ocfs2_get_system_file_inode(struct ocfs2_super * osb,int type,u32 slot)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 	mutex_lock(&osb->system_file_mutex);
102 	if (arr && ((inode = *arr) != NULL)) {
103 		/* get a ref in addition to the array ref */
104 		inode = igrab(inode);
105 		mutex_unlock(&osb->system_file_mutex);
106 		BUG_ON(!inode);
107 
108 		return inode;
109 	}
110 
111 	/* this gets one ref thru iget */
112 	inode = _ocfs2_get_system_file_inode(osb, type, slot);
113 
114 	/* add one more if putting into array for first time */
115 	if (arr && inode) {
116 		*arr = igrab(inode);
117 		BUG_ON(!*arr);
118 	}
119 	mutex_unlock(&osb->system_file_mutex);
120 	return inode;
121 }
122 
_ocfs2_get_system_file_inode(struct ocfs2_super * osb,int type,u32 slot)123 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
124 						   int type,
125 						   u32 slot)
126 {
127 	char namebuf[40];
128 	struct inode *inode = NULL;
129 	u64 blkno;
130 	int status = 0;
131 
132 	ocfs2_sprintf_system_inode_name(namebuf,
133 					sizeof(namebuf),
134 					type, slot);
135 
136 	status = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
137 					    strlen(namebuf), &blkno);
138 	if (status < 0) {
139 		goto bail;
140 	}
141 
142 	inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
143 	if (IS_ERR(inode)) {
144 		mlog_errno(PTR_ERR(inode));
145 		inode = NULL;
146 		goto bail;
147 	}
148 #ifdef CONFIG_DEBUG_LOCK_ALLOC
149 	if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
150 	    type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
151 	    type == JOURNAL_SYSTEM_INODE) {
152 		/* Ignore inode lock on these inodes as the lock does not
153 		 * really belong to any process and lockdep cannot handle
154 		 * that */
155 		OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
156 	} else {
157 		lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
158 								l_lockdep_map,
159 				 ocfs2_system_inodes[type].si_name,
160 				 &ocfs2_sysfile_cluster_lock_key[type], 0);
161 	}
162 #endif
163 bail:
164 
165 	return inode;
166 }
167 
168