summaryrefslogtreecommitdiff
path: root/fs/aufs/module.c
blob: ec12f2e6617a93a6440a20e5b0b51b58a172acb3 (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
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
/*
 * Copyright (C) 2005-2016 Junjiro R. Okajima
 */

/*
 * module global variables and operations
 */

#include <linux/module.h>
#include <linux/seq_file.h>
#include "aufs.h"

void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp)
{
	if (new_sz <= nused)
		return p;

	p = krealloc(p, new_sz, gfp);
	if (p)
		memset(p + nused, 0, new_sz - nused);
	return p;
}

/* ---------------------------------------------------------------------- */

/*
 * aufs caches
 */
struct kmem_cache *au_cachep[AuCache_Last];
static int __init au_cache_init(void)
{
	au_cachep[AuCache_DINFO] = AuCacheCtor(au_dinfo, au_di_init_once);
	if (au_cachep[AuCache_DINFO])
		/* SLAB_DESTROY_BY_RCU */
		au_cachep[AuCache_ICNTNR] = AuCacheCtor(au_icntnr,
							au_icntnr_init_once);
	if (au_cachep[AuCache_ICNTNR])
		au_cachep[AuCache_FINFO] = AuCacheCtor(au_finfo,
						       au_fi_init_once);
	if (au_cachep[AuCache_FINFO])
		au_cachep[AuCache_VDIR] = AuCache(au_vdir);
	if (au_cachep[AuCache_VDIR])
		au_cachep[AuCache_DEHSTR] = AuCache(au_vdir_dehstr);
	if (au_cachep[AuCache_DEHSTR])
		return 0;

	return -ENOMEM;
}

static void au_cache_fin(void)
{
	int i;

	/*
	 * Make sure all delayed rcu free inodes are flushed before we
	 * destroy cache.
	 */
	rcu_barrier();

	/* excluding AuCache_HNOTIFY */
	BUILD_BUG_ON(AuCache_HNOTIFY + 1 != AuCache_Last);
	for (i = 0; i < AuCache_HNOTIFY; i++) {
		kmem_cache_destroy(au_cachep[i]);
		au_cachep[i] = NULL;
	}
}

/* ---------------------------------------------------------------------- */

int au_dir_roflags;

#ifdef CONFIG_AUFS_SBILIST
/*
 * iterate_supers_type() doesn't protect us from
 * remounting (branch management)
 */
struct au_splhead au_sbilist;
#endif

struct lock_class_key au_lc_key[AuLcKey_Last];

/*
 * functions for module interface.
 */
MODULE_LICENSE("GPL");
/* MODULE_LICENSE("GPL v2"); */
MODULE_AUTHOR("Junjiro R. Okajima <aufs-users@lists.sourceforge.net>");
MODULE_DESCRIPTION(AUFS_NAME
	" -- Advanced multi layered unification filesystem");
MODULE_VERSION(AUFS_VERSION);

/* this module parameter has no meaning when SYSFS is disabled */
int sysaufs_brs = 1;
MODULE_PARM_DESC(brs, "use <sysfs>/fs/aufs/si_*/brN");
module_param_named(brs, sysaufs_brs, int, S_IRUGO);

/* this module parameter has no meaning when USER_NS is disabled */
static bool au_userns;
MODULE_PARM_DESC(allow_userns, "allow unprivileged to mount under userns");
module_param_named(allow_userns, au_userns, bool, S_IRUGO);

/* ---------------------------------------------------------------------- */

static char au_esc_chars[0x20 + 3]; /* 0x01-0x20, backslash, del, and NULL */

int au_seq_path(struct seq_file *seq, struct path *path)
{
	int err;

	err = seq_path(seq, path, au_esc_chars);
	if (err > 0)
		err = 0;
	else if (err < 0)
		err = -ENOMEM;

	return err;
}

/* ---------------------------------------------------------------------- */

static int __init aufs_init(void)
{
	int err, i;
	char *p;

	p = au_esc_chars;
	for (i = 1; i <= ' '; i++)
		*p++ = i;
	*p++ = '\\';
	*p++ = '\x7f';
	*p = 0;

	au_dir_roflags = au_file_roflags(O_DIRECTORY | O_LARGEFILE);

	memcpy(aufs_iop_nogetattr, aufs_iop, sizeof(aufs_iop));
	for (i = 0; i < AuIop_Last; i++)
		aufs_iop_nogetattr[i].getattr = NULL;

	au_sbilist_init();
	sysaufs_brs_init();
	au_debug_init();
	au_dy_init();
	err = sysaufs_init();
	if (unlikely(err))
		goto out;
	err = au_procfs_init();
	if (unlikely(err))
		goto out_sysaufs;
	err = au_wkq_init();
	if (unlikely(err))
		goto out_procfs;
	err = au_loopback_init();
	if (unlikely(err))
		goto out_wkq;
	err = au_hnotify_init();
	if (unlikely(err))
		goto out_loopback;
	err = au_sysrq_init();
	if (unlikely(err))
		goto out_hin;
	err = au_cache_init();
	if (unlikely(err))
		goto out_sysrq;

	aufs_fs_type.fs_flags |= au_userns ? FS_USERNS_MOUNT : 0;
	err = register_filesystem(&aufs_fs_type);
	if (unlikely(err))
		goto out_cache;

	/* since we define pr_fmt, call printk directly */
	printk(KERN_INFO AUFS_NAME " " AUFS_VERSION "\n");
	goto out; /* success */

out_cache:
	au_cache_fin();
out_sysrq:
	au_sysrq_fin();
out_hin:
	au_hnotify_fin();
out_loopback:
	au_loopback_fin();
out_wkq:
	au_wkq_fin();
out_procfs:
	au_procfs_fin();
out_sysaufs:
	sysaufs_fin();
	au_dy_fin();
out:
	return err;
}

static void __exit aufs_exit(void)
{
	unregister_filesystem(&aufs_fs_type);
	au_cache_fin();
	au_sysrq_fin();
	au_hnotify_fin();
	au_loopback_fin();
	au_wkq_fin();
	au_procfs_fin();
	sysaufs_fin();
	au_dy_fin();
}

module_init(aufs_init);
module_exit(aufs_exit);