xref: /kernel/linux/linux-5.10/fs/ocfs2/sysfile.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* -*- mode: c; c-basic-offset: 8; -*-
3 * vim: noexpandtab sw=8 ts=8 sts=0:
4 *
5 * sysfile.c
6 *
7 * Initialize, read, write, etc. system files.
8 *
9 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
10 */
11
12#include <linux/fs.h>
13#include <linux/types.h>
14#include <linux/highmem.h>
15
16#include <cluster/masklog.h>
17
18#include "ocfs2.h"
19
20#include "alloc.h"
21#include "dir.h"
22#include "inode.h"
23#include "journal.h"
24#include "sysfile.h"
25
26#include "buffer_head_io.h"
27
28static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
29						   int type,
30						   u32 slot);
31
32#ifdef CONFIG_DEBUG_LOCK_ALLOC
33static struct lock_class_key ocfs2_sysfile_cluster_lock_key[NUM_SYSTEM_INODES];
34#endif
35
36static inline int is_global_system_inode(int type)
37{
38	return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
39		type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
40}
41
42static struct inode **get_local_system_inode(struct ocfs2_super *osb,
43					     int type,
44					     u32 slot)
45{
46	int index;
47	struct inode **local_system_inodes, **free = NULL;
48
49	BUG_ON(slot == OCFS2_INVALID_SLOT);
50	BUG_ON(type < OCFS2_FIRST_LOCAL_SYSTEM_INODE ||
51	       type > OCFS2_LAST_LOCAL_SYSTEM_INODE);
52
53	spin_lock(&osb->osb_lock);
54	local_system_inodes = osb->local_system_inodes;
55	spin_unlock(&osb->osb_lock);
56
57	if (unlikely(!local_system_inodes)) {
58		local_system_inodes =
59			kzalloc(array3_size(sizeof(struct inode *),
60					    NUM_LOCAL_SYSTEM_INODES,
61					    osb->max_slots),
62				GFP_NOFS);
63		if (!local_system_inodes) {
64			mlog_errno(-ENOMEM);
65			/*
66			 * return NULL here so that ocfs2_get_sytem_file_inodes
67			 * will try to create an inode and use it. We will try
68			 * to initialize local_system_inodes next time.
69			 */
70			return NULL;
71		}
72
73		spin_lock(&osb->osb_lock);
74		if (osb->local_system_inodes) {
75			/* Someone has initialized it for us. */
76			free = local_system_inodes;
77			local_system_inodes = osb->local_system_inodes;
78		} else
79			osb->local_system_inodes = local_system_inodes;
80		spin_unlock(&osb->osb_lock);
81		kfree(free);
82	}
83
84	index = (slot * NUM_LOCAL_SYSTEM_INODES) +
85		(type - OCFS2_FIRST_LOCAL_SYSTEM_INODE);
86
87	return &local_system_inodes[index];
88}
89
90struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
91					  int type,
92					  u32 slot)
93{
94	struct inode *inode = NULL;
95	struct inode **arr = NULL;
96
97	/* avoid the lookup if cached in local system file array */
98	if (is_global_system_inode(type)) {
99		arr = &(osb->global_system_inodes[type]);
100	} else
101		arr = get_local_system_inode(osb, type, slot);
102
103	mutex_lock(&osb->system_file_mutex);
104	if (arr && ((inode = *arr) != NULL)) {
105		/* get a ref in addition to the array ref */
106		inode = igrab(inode);
107		mutex_unlock(&osb->system_file_mutex);
108		BUG_ON(!inode);
109
110		return inode;
111	}
112
113	/* this gets one ref thru iget */
114	inode = _ocfs2_get_system_file_inode(osb, type, slot);
115
116	/* add one more if putting into array for first time */
117	if (arr && inode) {
118		*arr = igrab(inode);
119		BUG_ON(!*arr);
120	}
121	mutex_unlock(&osb->system_file_mutex);
122	return inode;
123}
124
125static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
126						   int type,
127						   u32 slot)
128{
129	char namebuf[40];
130	struct inode *inode = NULL;
131	u64 blkno;
132	int status = 0;
133
134	ocfs2_sprintf_system_inode_name(namebuf,
135					sizeof(namebuf),
136					type, slot);
137
138	status = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
139					    strlen(namebuf), &blkno);
140	if (status < 0) {
141		goto bail;
142	}
143
144	inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
145	if (IS_ERR(inode)) {
146		mlog_errno(PTR_ERR(inode));
147		inode = NULL;
148		goto bail;
149	}
150#ifdef CONFIG_DEBUG_LOCK_ALLOC
151	if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
152	    type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
153	    type == JOURNAL_SYSTEM_INODE) {
154		/* Ignore inode lock on these inodes as the lock does not
155		 * really belong to any process and lockdep cannot handle
156		 * that */
157		OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
158	} else {
159		lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
160								l_lockdep_map,
161				 ocfs2_system_inodes[type].si_name,
162				 &ocfs2_sysfile_cluster_lock_key[type], 0);
163	}
164#endif
165bail:
166
167	return inode;
168}
169
170