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e14748e8 SF |
1 | /* |
2 | * Copyright (C) 2005-2016 Junjiro R. Okajima | |
3 | * | |
4 | * This program, aufs is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
16 | */ | |
17 | ||
18 | /* | |
19 | * module global variables and operations | |
20 | */ | |
21 | ||
22 | #include <linux/module.h> | |
23 | #include <linux/seq_file.h> | |
24 | #include "aufs.h" | |
25 | ||
26 | /* shrinkable realloc */ | |
27 | void *au_krealloc(void *p, unsigned int new_sz, gfp_t gfp, int may_shrink) | |
28 | { | |
29 | size_t sz; | |
30 | int diff; | |
31 | ||
32 | sz = 0; | |
33 | diff = -1; | |
34 | if (p) { | |
35 | #if 0 /* unused */ | |
36 | if (!new_sz) { | |
37 | au_delayed_kfree(p); | |
38 | p = NULL; | |
39 | goto out; | |
40 | } | |
41 | #else | |
42 | AuDebugOn(!new_sz); | |
43 | #endif | |
44 | sz = ksize(p); | |
45 | diff = au_kmidx_sub(sz, new_sz); | |
46 | } | |
47 | if (sz && !diff) | |
48 | goto out; | |
49 | ||
50 | if (sz < new_sz) | |
51 | /* expand or SLOB */ | |
52 | p = krealloc(p, new_sz, gfp); | |
53 | else if (new_sz < sz && may_shrink) { | |
54 | /* shrink */ | |
55 | void *q; | |
56 | ||
57 | q = kmalloc(new_sz, gfp); | |
58 | if (q) { | |
59 | if (p) { | |
60 | memcpy(q, p, new_sz); | |
61 | au_delayed_kfree(p); | |
62 | } | |
63 | p = q; | |
64 | } else | |
65 | p = NULL; | |
66 | } | |
67 | ||
68 | out: | |
69 | return p; | |
70 | } | |
71 | ||
72 | void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp, | |
73 | int may_shrink) | |
74 | { | |
75 | p = au_krealloc(p, new_sz, gfp, may_shrink); | |
76 | if (p && new_sz > nused) | |
77 | memset(p + nused, 0, new_sz - nused); | |
78 | return p; | |
79 | } | |
80 | ||
81 | /* ---------------------------------------------------------------------- */ | |
82 | /* | |
83 | * aufs caches | |
84 | */ | |
85 | ||
86 | struct au_dfree au_dfree; | |
87 | ||
88 | /* delayed free */ | |
89 | static void au_do_dfree(struct work_struct *work __maybe_unused) | |
90 | { | |
91 | struct llist_head *head; | |
92 | struct llist_node *node, *next; | |
93 | ||
94 | #define AU_CACHE_DFREE_DO_BODY(name, idx, lnode) do { \ | |
95 | head = &au_dfree.cache[AuCache_##idx].llist; \ | |
96 | node = llist_del_all(head); \ | |
97 | for (; node; node = next) { \ | |
98 | struct au_##name *p \ | |
99 | = llist_entry(node, struct au_##name, \ | |
100 | lnode); \ | |
101 | next = llist_next(node); \ | |
102 | au_cache_free_##name(p); \ | |
103 | } \ | |
104 | } while (0) | |
105 | ||
106 | AU_CACHE_DFREE_DO_BODY(dinfo, DINFO, di_lnode); | |
107 | AU_CACHE_DFREE_DO_BODY(icntnr, ICNTNR, lnode); | |
108 | AU_CACHE_DFREE_DO_BODY(finfo, FINFO, fi_lnode); | |
109 | AU_CACHE_DFREE_DO_BODY(vdir, VDIR, vd_lnode); | |
110 | AU_CACHE_DFREE_DO_BODY(vdir_dehstr, DEHSTR, lnode); | |
111 | #ifdef CONFIG_AUFS_HNOTIFY | |
112 | AU_CACHE_DFREE_DO_BODY(hnotify, HNOTIFY, hn_lnode); | |
113 | #endif | |
114 | ||
115 | #define AU_DFREE_DO_BODY(llist, func) do { \ | |
116 | node = llist_del_all(llist); \ | |
117 | for (; node; node = next) { \ | |
118 | next = llist_next(node); \ | |
119 | func(node); \ | |
120 | } \ | |
121 | } while (0) | |
122 | ||
123 | AU_DFREE_DO_BODY(au_dfree.llist + AU_DFREE_KFREE, kfree); | |
124 | AU_DFREE_DO_BODY(au_dfree.llist + AU_DFREE_FREE_PAGE, au_free_page); | |
125 | ||
126 | #undef AU_CACHE_DFREE_DO_BODY | |
127 | #undef AU_DFREE_DO_BODY | |
128 | } | |
129 | ||
130 | AU_CACHE_DFREE_FUNC(dinfo, DINFO, di_lnode); | |
131 | AU_CACHE_DFREE_FUNC(icntnr, ICNTNR, lnode); | |
132 | AU_CACHE_DFREE_FUNC(finfo, FINFO, fi_lnode); | |
133 | AU_CACHE_DFREE_FUNC(vdir, VDIR, vd_lnode); | |
134 | AU_CACHE_DFREE_FUNC(vdir_dehstr, DEHSTR, lnode); | |
135 | ||
136 | static void au_cache_fin(void) | |
137 | { | |
138 | int i; | |
139 | struct au_cache *cp; | |
140 | ||
141 | /* | |
142 | * Make sure all delayed rcu free inodes are flushed before we | |
143 | * destroy cache. | |
144 | */ | |
145 | rcu_barrier(); | |
146 | ||
147 | /* excluding AuCache_HNOTIFY */ | |
148 | BUILD_BUG_ON(AuCache_HNOTIFY + 1 != AuCache_Last); | |
149 | flush_delayed_work(&au_dfree.dwork); | |
150 | for (i = 0; i < AuCache_HNOTIFY; i++) { | |
151 | cp = au_dfree.cache + i; | |
152 | AuDebugOn(!llist_empty(&cp->llist)); | |
153 | kmem_cache_destroy(cp->cache); | |
154 | cp->cache = NULL; | |
155 | } | |
156 | } | |
157 | ||
158 | static int __init au_cache_init(void) | |
159 | { | |
160 | struct au_cache *cp; | |
161 | ||
162 | cp = au_dfree.cache; | |
163 | cp[AuCache_DINFO].cache = AuCacheCtor(au_dinfo, au_di_init_once); | |
164 | if (cp[AuCache_DINFO].cache) | |
165 | /* SLAB_DESTROY_BY_RCU */ | |
166 | cp[AuCache_ICNTNR].cache = AuCacheCtor(au_icntnr, | |
167 | au_icntnr_init_once); | |
168 | if (cp[AuCache_ICNTNR].cache) | |
169 | cp[AuCache_FINFO].cache = AuCacheCtor(au_finfo, | |
170 | au_fi_init_once); | |
171 | if (cp[AuCache_FINFO].cache) | |
172 | cp[AuCache_VDIR].cache = AuCache(au_vdir); | |
173 | if (cp[AuCache_VDIR].cache) | |
174 | cp[AuCache_DEHSTR].cache = AuCache(au_vdir_dehstr); | |
175 | if (cp[AuCache_DEHSTR].cache) | |
176 | return 0; | |
177 | ||
178 | au_cache_fin(); | |
179 | return -ENOMEM; | |
180 | } | |
181 | ||
182 | /* ---------------------------------------------------------------------- */ | |
183 | ||
184 | int au_dir_roflags; | |
185 | ||
186 | #ifdef CONFIG_AUFS_SBILIST | |
187 | /* | |
188 | * iterate_supers_type() doesn't protect us from | |
189 | * remounting (branch management) | |
190 | */ | |
191 | struct au_sphlhead au_sbilist; | |
192 | #endif | |
193 | ||
194 | /* | |
195 | * functions for module interface. | |
196 | */ | |
197 | MODULE_LICENSE("GPL"); | |
198 | /* MODULE_LICENSE("GPL v2"); */ | |
199 | MODULE_AUTHOR("Junjiro R. Okajima <aufs-users@lists.sourceforge.net>"); | |
200 | MODULE_DESCRIPTION(AUFS_NAME | |
201 | " -- Advanced multi layered unification filesystem"); | |
202 | MODULE_VERSION(AUFS_VERSION); | |
203 | MODULE_ALIAS_FS(AUFS_NAME); | |
204 | ||
205 | /* this module parameter has no meaning when SYSFS is disabled */ | |
206 | int sysaufs_brs = 1; | |
207 | MODULE_PARM_DESC(brs, "use <sysfs>/fs/aufs/si_*/brN"); | |
208 | module_param_named(brs, sysaufs_brs, int, S_IRUGO); | |
209 | ||
210 | /* this module parameter has no meaning when USER_NS is disabled */ | |
211 | bool au_userns; | |
212 | MODULE_PARM_DESC(allow_userns, "allow unprivileged to mount under userns"); | |
213 | module_param_named(allow_userns, au_userns, bool, S_IRUGO); | |
214 | ||
215 | /* ---------------------------------------------------------------------- */ | |
216 | ||
217 | static char au_esc_chars[0x20 + 3]; /* 0x01-0x20, backslash, del, and NULL */ | |
218 | ||
219 | int au_seq_path(struct seq_file *seq, struct path *path) | |
220 | { | |
221 | int err; | |
222 | ||
223 | err = seq_path(seq, path, au_esc_chars); | |
224 | if (err > 0) | |
225 | err = 0; | |
226 | else if (err < 0) | |
227 | err = -ENOMEM; | |
228 | ||
229 | return err; | |
230 | } | |
231 | ||
232 | /* ---------------------------------------------------------------------- */ | |
233 | ||
234 | static int __init aufs_init(void) | |
235 | { | |
236 | int err, i; | |
237 | char *p; | |
238 | struct au_cache *cp; | |
239 | ||
240 | p = au_esc_chars; | |
241 | for (i = 1; i <= ' '; i++) | |
242 | *p++ = i; | |
243 | *p++ = '\\'; | |
244 | *p++ = '\x7f'; | |
245 | *p = 0; | |
246 | ||
247 | au_dir_roflags = au_file_roflags(O_DIRECTORY | O_LARGEFILE); | |
248 | ||
249 | memcpy(aufs_iop_nogetattr, aufs_iop, sizeof(aufs_iop)); | |
250 | for (i = 0; i < AuIop_Last; i++) | |
251 | aufs_iop_nogetattr[i].getattr = NULL; | |
252 | ||
253 | /* First, initialize au_dfree */ | |
254 | for (i = 0; i < AuCache_Last; i++) { /* including hnotify */ | |
255 | cp = au_dfree.cache + i; | |
256 | cp->cache = NULL; | |
257 | init_llist_head(&cp->llist); | |
258 | } | |
259 | for (i = 0; i < AU_DFREE_Last; i++) | |
260 | init_llist_head(au_dfree.llist + i); | |
261 | INIT_DELAYED_WORK(&au_dfree.dwork, au_do_dfree); | |
262 | ||
263 | au_sbilist_init(); | |
264 | sysaufs_brs_init(); | |
265 | au_debug_init(); | |
266 | au_dy_init(); | |
267 | err = sysaufs_init(); | |
268 | if (unlikely(err)) | |
269 | goto out; | |
270 | err = au_procfs_init(); | |
271 | if (unlikely(err)) | |
272 | goto out_sysaufs; | |
273 | err = au_wkq_init(); | |
274 | if (unlikely(err)) | |
275 | goto out_procfs; | |
276 | err = au_loopback_init(); | |
277 | if (unlikely(err)) | |
278 | goto out_wkq; | |
279 | err = au_hnotify_init(); | |
280 | if (unlikely(err)) | |
281 | goto out_loopback; | |
282 | err = au_sysrq_init(); | |
283 | if (unlikely(err)) | |
284 | goto out_hin; | |
285 | err = au_cache_init(); | |
286 | if (unlikely(err)) | |
287 | goto out_sysrq; | |
288 | ||
289 | aufs_fs_type.fs_flags |= au_userns ? FS_USERNS_MOUNT : 0; | |
290 | err = register_filesystem(&aufs_fs_type); | |
291 | if (unlikely(err)) | |
292 | goto out_cache; | |
293 | ||
294 | /* since we define pr_fmt, call printk directly */ | |
295 | printk(KERN_INFO AUFS_NAME " " AUFS_VERSION "\n"); | |
296 | goto out; /* success */ | |
297 | ||
298 | out_cache: | |
299 | au_cache_fin(); | |
300 | out_sysrq: | |
301 | au_sysrq_fin(); | |
302 | out_hin: | |
303 | au_hnotify_fin(); | |
304 | out_loopback: | |
305 | au_loopback_fin(); | |
306 | out_wkq: | |
307 | au_wkq_fin(); | |
308 | out_procfs: | |
309 | au_procfs_fin(); | |
310 | out_sysaufs: | |
311 | sysaufs_fin(); | |
312 | au_dy_fin(); | |
313 | flush_delayed_work(&au_dfree.dwork); | |
314 | out: | |
315 | return err; | |
316 | } | |
317 | ||
318 | static void __exit aufs_exit(void) | |
319 | { | |
320 | unregister_filesystem(&aufs_fs_type); | |
321 | au_cache_fin(); | |
322 | au_sysrq_fin(); | |
323 | au_hnotify_fin(); | |
324 | au_loopback_fin(); | |
325 | au_wkq_fin(); | |
326 | au_procfs_fin(); | |
327 | sysaufs_fin(); | |
328 | au_dy_fin(); | |
329 | flush_delayed_work(&au_dfree.dwork); | |
330 | } | |
331 | ||
332 | module_init(aufs_init); | |
333 | module_exit(aufs_exit); |