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a3a49a17 SF |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
e4a3f096 | 3 | * Copyright (C) 2005-2020 Junjiro R. Okajima |
a3a49a17 SF |
4 | * |
5 | * This program, aufs is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
17 | */ | |
18 | ||
19 | /* | |
20 | * module global variables and operations | |
21 | */ | |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/seq_file.h> | |
25 | #include "aufs.h" | |
26 | ||
27 | /* shrinkable realloc */ | |
28 | void *au_krealloc(void *p, unsigned int new_sz, gfp_t gfp, int may_shrink) | |
29 | { | |
30 | size_t sz; | |
31 | int diff; | |
32 | ||
33 | sz = 0; | |
34 | diff = -1; | |
35 | if (p) { | |
36 | #if 0 /* unused */ | |
37 | if (!new_sz) { | |
38 | au_kfree_rcu(p); | |
39 | p = NULL; | |
40 | goto out; | |
41 | } | |
42 | #else | |
43 | AuDebugOn(!new_sz); | |
44 | #endif | |
45 | sz = ksize(p); | |
46 | diff = au_kmidx_sub(sz, new_sz); | |
47 | } | |
48 | if (sz && !diff) | |
49 | goto out; | |
50 | ||
51 | if (sz < new_sz) | |
52 | /* expand or SLOB */ | |
53 | p = krealloc(p, new_sz, gfp); | |
54 | else if (new_sz < sz && may_shrink) { | |
55 | /* shrink */ | |
56 | void *q; | |
57 | ||
58 | q = kmalloc(new_sz, gfp); | |
59 | if (q) { | |
60 | if (p) { | |
61 | memcpy(q, p, new_sz); | |
62 | au_kfree_try_rcu(p); | |
63 | } | |
64 | p = q; | |
65 | } else | |
66 | p = NULL; | |
67 | } | |
68 | ||
69 | out: | |
70 | return p; | |
71 | } | |
72 | ||
73 | void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp, | |
74 | int may_shrink) | |
75 | { | |
76 | p = au_krealloc(p, new_sz, gfp, may_shrink); | |
77 | if (p && new_sz > nused) | |
78 | memset(p + nused, 0, new_sz - nused); | |
79 | return p; | |
80 | } | |
81 | ||
82 | /* ---------------------------------------------------------------------- */ | |
83 | /* | |
84 | * aufs caches | |
85 | */ | |
86 | struct kmem_cache *au_cache[AuCache_Last]; | |
87 | ||
88 | static void au_cache_fin(void) | |
89 | { | |
90 | int i; | |
91 | ||
92 | /* | |
93 | * Make sure all delayed rcu free inodes are flushed before we | |
94 | * destroy cache. | |
95 | */ | |
96 | rcu_barrier(); | |
97 | ||
98 | /* excluding AuCache_HNOTIFY */ | |
99 | BUILD_BUG_ON(AuCache_HNOTIFY + 1 != AuCache_Last); | |
100 | for (i = 0; i < AuCache_HNOTIFY; i++) { | |
101 | kmem_cache_destroy(au_cache[i]); | |
102 | au_cache[i] = NULL; | |
103 | } | |
104 | } | |
105 | ||
106 | static int __init au_cache_init(void) | |
107 | { | |
108 | au_cache[AuCache_DINFO] = AuCacheCtor(au_dinfo, au_di_init_once); | |
109 | if (au_cache[AuCache_DINFO]) | |
110 | /* SLAB_DESTROY_BY_RCU */ | |
111 | au_cache[AuCache_ICNTNR] = AuCacheCtor(au_icntnr, | |
112 | au_icntnr_init_once); | |
113 | if (au_cache[AuCache_ICNTNR]) | |
114 | au_cache[AuCache_FINFO] = AuCacheCtor(au_finfo, | |
115 | au_fi_init_once); | |
116 | if (au_cache[AuCache_FINFO]) | |
117 | au_cache[AuCache_VDIR] = AuCache(au_vdir); | |
118 | if (au_cache[AuCache_VDIR]) | |
119 | au_cache[AuCache_DEHSTR] = AuCache(au_vdir_dehstr); | |
120 | if (au_cache[AuCache_DEHSTR]) | |
121 | return 0; | |
122 | ||
123 | au_cache_fin(); | |
124 | return -ENOMEM; | |
125 | } | |
126 | ||
127 | /* ---------------------------------------------------------------------- */ | |
128 | ||
129 | int au_dir_roflags; | |
130 | ||
131 | #ifdef CONFIG_AUFS_SBILIST | |
132 | /* | |
133 | * iterate_supers_type() doesn't protect us from | |
134 | * remounting (branch management) | |
135 | */ | |
136 | struct hlist_bl_head au_sbilist; | |
137 | #endif | |
138 | ||
139 | /* | |
140 | * functions for module interface. | |
141 | */ | |
142 | MODULE_LICENSE("GPL"); | |
143 | /* MODULE_LICENSE("GPL v2"); */ | |
144 | MODULE_AUTHOR("Junjiro R. Okajima <aufs-users@lists.sourceforge.net>"); | |
145 | MODULE_DESCRIPTION(AUFS_NAME | |
146 | " -- Advanced multi layered unification filesystem"); | |
147 | MODULE_VERSION(AUFS_VERSION); | |
148 | MODULE_ALIAS_FS(AUFS_NAME); | |
149 | ||
150 | /* this module parameter has no meaning when SYSFS is disabled */ | |
151 | int sysaufs_brs = 1; | |
152 | MODULE_PARM_DESC(brs, "use <sysfs>/fs/aufs/si_*/brN"); | |
153 | module_param_named(brs, sysaufs_brs, int, 0444); | |
154 | ||
155 | /* this module parameter has no meaning when USER_NS is disabled */ | |
156 | bool au_userns; | |
157 | MODULE_PARM_DESC(allow_userns, "allow unprivileged to mount under userns"); | |
158 | module_param_named(allow_userns, au_userns, bool, 0444); | |
159 | ||
160 | /* ---------------------------------------------------------------------- */ | |
161 | ||
162 | static char au_esc_chars[0x20 + 3]; /* 0x01-0x20, backslash, del, and NULL */ | |
163 | ||
164 | int au_seq_path(struct seq_file *seq, struct path *path) | |
165 | { | |
166 | int err; | |
167 | ||
168 | err = seq_path(seq, path, au_esc_chars); | |
169 | if (err >= 0) | |
170 | err = 0; | |
171 | else | |
172 | err = -ENOMEM; | |
173 | ||
174 | return err; | |
175 | } | |
176 | ||
177 | /* ---------------------------------------------------------------------- */ | |
178 | ||
179 | static int __init aufs_init(void) | |
180 | { | |
181 | int err, i; | |
182 | char *p; | |
183 | ||
184 | p = au_esc_chars; | |
185 | for (i = 1; i <= ' '; i++) | |
186 | *p++ = i; | |
187 | *p++ = '\\'; | |
188 | *p++ = '\x7f'; | |
189 | *p = 0; | |
190 | ||
191 | au_dir_roflags = au_file_roflags(O_DIRECTORY | O_LARGEFILE); | |
192 | ||
193 | memcpy(aufs_iop_nogetattr, aufs_iop, sizeof(aufs_iop)); | |
194 | for (i = 0; i < AuIop_Last; i++) | |
195 | aufs_iop_nogetattr[i].getattr = NULL; | |
196 | ||
197 | memset(au_cache, 0, sizeof(au_cache)); /* including hnotify */ | |
198 | ||
199 | au_sbilist_init(); | |
200 | sysaufs_brs_init(); | |
201 | au_debug_init(); | |
202 | au_dy_init(); | |
203 | err = sysaufs_init(); | |
204 | if (unlikely(err)) | |
205 | goto out; | |
206 | err = dbgaufs_init(); | |
207 | if (unlikely(err)) | |
208 | goto out_sysaufs; | |
209 | err = au_procfs_init(); | |
210 | if (unlikely(err)) | |
211 | goto out_dbgaufs; | |
212 | err = au_wkq_init(); | |
213 | if (unlikely(err)) | |
214 | goto out_procfs; | |
215 | err = au_loopback_init(); | |
216 | if (unlikely(err)) | |
217 | goto out_wkq; | |
218 | err = au_hnotify_init(); | |
219 | if (unlikely(err)) | |
220 | goto out_loopback; | |
221 | err = au_sysrq_init(); | |
222 | if (unlikely(err)) | |
223 | goto out_hin; | |
224 | err = au_cache_init(); | |
225 | if (unlikely(err)) | |
226 | goto out_sysrq; | |
227 | ||
228 | aufs_fs_type.fs_flags |= au_userns ? FS_USERNS_MOUNT : 0; | |
229 | err = register_filesystem(&aufs_fs_type); | |
230 | if (unlikely(err)) | |
231 | goto out_cache; | |
232 | ||
233 | /* since we define pr_fmt, call printk directly */ | |
234 | printk(KERN_INFO AUFS_NAME " " AUFS_VERSION "\n"); | |
235 | goto out; /* success */ | |
236 | ||
237 | out_cache: | |
238 | au_cache_fin(); | |
239 | out_sysrq: | |
240 | au_sysrq_fin(); | |
241 | out_hin: | |
242 | au_hnotify_fin(); | |
243 | out_loopback: | |
244 | au_loopback_fin(); | |
245 | out_wkq: | |
246 | au_wkq_fin(); | |
247 | out_procfs: | |
248 | au_procfs_fin(); | |
249 | out_dbgaufs: | |
250 | dbgaufs_fin(); | |
251 | out_sysaufs: | |
252 | sysaufs_fin(); | |
253 | au_dy_fin(); | |
254 | out: | |
255 | return err; | |
256 | } | |
257 | ||
258 | static void __exit aufs_exit(void) | |
259 | { | |
260 | unregister_filesystem(&aufs_fs_type); | |
261 | au_cache_fin(); | |
262 | au_sysrq_fin(); | |
263 | au_hnotify_fin(); | |
264 | au_loopback_fin(); | |
265 | au_wkq_fin(); | |
266 | au_procfs_fin(); | |
267 | dbgaufs_fin(); | |
268 | sysaufs_fin(); | |
269 | au_dy_fin(); | |
270 | } | |
271 | ||
272 | module_init(aufs_init); | |
273 | module_exit(aufs_exit); |