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c088e31d SF |
1 | /* |
2 | * Copyright (C) 2005-2017 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 | * fsnotify for the lower directories | |
20 | */ | |
21 | ||
22 | #include "aufs.h" | |
23 | ||
24 | /* FS_IN_IGNORED is unnecessary */ | |
25 | static const __u32 AuHfsnMask = (FS_MOVED_TO | FS_MOVED_FROM | FS_DELETE | |
26 | | FS_CREATE | FS_EVENT_ON_CHILD); | |
27 | static DECLARE_WAIT_QUEUE_HEAD(au_hfsn_wq); | |
28 | static __cacheline_aligned_in_smp atomic64_t au_hfsn_ifree = ATOMIC64_INIT(0); | |
29 | ||
30 | static void au_hfsn_free_mark(struct fsnotify_mark *mark) | |
31 | { | |
32 | struct au_hnotify *hn = container_of(mark, struct au_hnotify, | |
33 | hn_mark); | |
34 | /* AuDbg("here\n"); */ | |
35 | au_cache_free_hnotify(hn); | |
36 | smp_mb__before_atomic(); /* for atomic64_dec */ | |
37 | if (atomic64_dec_and_test(&au_hfsn_ifree)) | |
38 | wake_up(&au_hfsn_wq); | |
39 | } | |
40 | ||
41 | static int au_hfsn_alloc(struct au_hinode *hinode) | |
42 | { | |
43 | int err; | |
44 | struct au_hnotify *hn; | |
45 | struct super_block *sb; | |
46 | struct au_branch *br; | |
47 | struct fsnotify_mark *mark; | |
48 | aufs_bindex_t bindex; | |
49 | ||
50 | hn = hinode->hi_notify; | |
51 | sb = hn->hn_aufs_inode->i_sb; | |
52 | bindex = au_br_index(sb, hinode->hi_id); | |
53 | br = au_sbr(sb, bindex); | |
54 | AuDebugOn(!br->br_hfsn); | |
55 | ||
56 | mark = &hn->hn_mark; | |
57 | fsnotify_init_mark(mark, br->br_hfsn->hfsn_group); | |
58 | mark->mask = AuHfsnMask; | |
59 | /* | |
60 | * by udba rename or rmdir, aufs assign a new inode to the known | |
61 | * h_inode, so specify 1 to allow dups. | |
62 | */ | |
63 | lockdep_off(); | |
64 | err = fsnotify_add_mark(mark, hinode->hi_inode, /*mnt*/NULL, | |
65 | /*allow_dups*/1); | |
66 | lockdep_on(); | |
67 | ||
68 | return err; | |
69 | } | |
70 | ||
71 | static int au_hfsn_free(struct au_hinode *hinode, struct au_hnotify *hn) | |
72 | { | |
73 | struct fsnotify_mark *mark; | |
74 | unsigned long long ull; | |
75 | struct fsnotify_group *group; | |
76 | ||
77 | ull = atomic64_inc_return(&au_hfsn_ifree); | |
78 | BUG_ON(!ull); | |
79 | ||
80 | mark = &hn->hn_mark; | |
81 | spin_lock(&mark->lock); | |
82 | group = mark->group; | |
83 | fsnotify_get_group(group); | |
84 | spin_unlock(&mark->lock); | |
85 | lockdep_off(); | |
86 | fsnotify_destroy_mark(mark, group); | |
87 | fsnotify_put_mark(mark); | |
88 | fsnotify_put_group(group); | |
89 | lockdep_on(); | |
90 | ||
91 | /* free hn by myself */ | |
92 | return 0; | |
93 | } | |
94 | ||
95 | /* ---------------------------------------------------------------------- */ | |
96 | ||
97 | static void au_hfsn_ctl(struct au_hinode *hinode, int do_set) | |
98 | { | |
99 | struct fsnotify_mark *mark; | |
100 | ||
101 | mark = &hinode->hi_notify->hn_mark; | |
102 | spin_lock(&mark->lock); | |
103 | if (do_set) { | |
104 | AuDebugOn(mark->mask & AuHfsnMask); | |
105 | mark->mask |= AuHfsnMask; | |
106 | } else { | |
107 | AuDebugOn(!(mark->mask & AuHfsnMask)); | |
108 | mark->mask &= ~AuHfsnMask; | |
109 | } | |
110 | spin_unlock(&mark->lock); | |
111 | /* fsnotify_recalc_inode_mask(hinode->hi_inode); */ | |
112 | } | |
113 | ||
114 | /* ---------------------------------------------------------------------- */ | |
115 | ||
116 | /* #define AuDbgHnotify */ | |
117 | #ifdef AuDbgHnotify | |
118 | static char *au_hfsn_name(u32 mask) | |
119 | { | |
120 | #ifdef CONFIG_AUFS_DEBUG | |
121 | #define test_ret(flag) \ | |
122 | do { \ | |
123 | if (mask & flag) \ | |
124 | return #flag; \ | |
125 | } while (0) | |
126 | test_ret(FS_ACCESS); | |
127 | test_ret(FS_MODIFY); | |
128 | test_ret(FS_ATTRIB); | |
129 | test_ret(FS_CLOSE_WRITE); | |
130 | test_ret(FS_CLOSE_NOWRITE); | |
131 | test_ret(FS_OPEN); | |
132 | test_ret(FS_MOVED_FROM); | |
133 | test_ret(FS_MOVED_TO); | |
134 | test_ret(FS_CREATE); | |
135 | test_ret(FS_DELETE); | |
136 | test_ret(FS_DELETE_SELF); | |
137 | test_ret(FS_MOVE_SELF); | |
138 | test_ret(FS_UNMOUNT); | |
139 | test_ret(FS_Q_OVERFLOW); | |
140 | test_ret(FS_IN_IGNORED); | |
141 | test_ret(FS_ISDIR); | |
142 | test_ret(FS_IN_ONESHOT); | |
143 | test_ret(FS_EVENT_ON_CHILD); | |
144 | return ""; | |
145 | #undef test_ret | |
146 | #else | |
147 | return "??"; | |
148 | #endif | |
149 | } | |
150 | #endif | |
151 | ||
152 | /* ---------------------------------------------------------------------- */ | |
153 | ||
154 | static void au_hfsn_free_group(struct fsnotify_group *group) | |
155 | { | |
156 | struct au_br_hfsnotify *hfsn = group->private; | |
157 | ||
158 | /* AuDbg("here\n"); */ | |
159 | kfree(hfsn); | |
160 | } | |
161 | ||
162 | static int au_hfsn_handle_event(struct fsnotify_group *group, | |
163 | struct inode *inode, | |
164 | struct fsnotify_mark *inode_mark, | |
165 | struct fsnotify_mark *vfsmount_mark, | |
166 | u32 mask, const void *data, int data_type, | |
167 | const unsigned char *file_name, u32 cookie, | |
168 | struct fsnotify_iter_info *iter_info) | |
169 | { | |
170 | int err; | |
171 | struct au_hnotify *hnotify; | |
172 | struct inode *h_dir, *h_inode; | |
173 | struct qstr h_child_qstr = QSTR_INIT(file_name, strlen(file_name)); | |
174 | ||
175 | AuDebugOn(data_type != FSNOTIFY_EVENT_INODE); | |
176 | ||
177 | err = 0; | |
178 | /* if FS_UNMOUNT happens, there must be another bug */ | |
179 | AuDebugOn(mask & FS_UNMOUNT); | |
180 | if (mask & (FS_IN_IGNORED | FS_UNMOUNT)) | |
181 | goto out; | |
182 | ||
183 | h_dir = inode; | |
184 | h_inode = NULL; | |
185 | #ifdef AuDbgHnotify | |
186 | au_debug_on(); | |
187 | if (1 || h_child_qstr.len != sizeof(AUFS_XINO_FNAME) - 1 | |
188 | || strncmp(h_child_qstr.name, AUFS_XINO_FNAME, h_child_qstr.len)) { | |
189 | AuDbg("i%lu, mask 0x%x %s, hcname %.*s, hi%lu\n", | |
190 | h_dir->i_ino, mask, au_hfsn_name(mask), | |
191 | AuLNPair(&h_child_qstr), h_inode ? h_inode->i_ino : 0); | |
192 | /* WARN_ON(1); */ | |
193 | } | |
194 | au_debug_off(); | |
195 | #endif | |
196 | ||
197 | AuDebugOn(!inode_mark); | |
198 | hnotify = container_of(inode_mark, struct au_hnotify, hn_mark); | |
199 | err = au_hnotify(h_dir, hnotify, mask, &h_child_qstr, h_inode); | |
200 | ||
201 | out: | |
202 | return err; | |
203 | } | |
204 | ||
205 | static struct fsnotify_ops au_hfsn_ops = { | |
206 | .handle_event = au_hfsn_handle_event, | |
207 | .free_group_priv = au_hfsn_free_group, | |
208 | .free_mark = au_hfsn_free_mark | |
209 | }; | |
210 | ||
211 | /* ---------------------------------------------------------------------- */ | |
212 | ||
213 | static void au_hfsn_fin_br(struct au_branch *br) | |
214 | { | |
215 | struct au_br_hfsnotify *hfsn; | |
216 | ||
217 | hfsn = br->br_hfsn; | |
218 | if (hfsn) { | |
219 | lockdep_off(); | |
220 | fsnotify_put_group(hfsn->hfsn_group); | |
221 | lockdep_on(); | |
222 | } | |
223 | } | |
224 | ||
225 | static int au_hfsn_init_br(struct au_branch *br, int perm) | |
226 | { | |
227 | int err; | |
228 | struct fsnotify_group *group; | |
229 | struct au_br_hfsnotify *hfsn; | |
230 | ||
231 | err = 0; | |
232 | br->br_hfsn = NULL; | |
233 | if (!au_br_hnotifyable(perm)) | |
234 | goto out; | |
235 | ||
236 | err = -ENOMEM; | |
237 | hfsn = kmalloc(sizeof(*hfsn), GFP_NOFS); | |
238 | if (unlikely(!hfsn)) | |
239 | goto out; | |
240 | ||
241 | err = 0; | |
242 | group = fsnotify_alloc_group(&au_hfsn_ops); | |
243 | if (IS_ERR(group)) { | |
244 | err = PTR_ERR(group); | |
245 | pr_err("fsnotify_alloc_group() failed, %d\n", err); | |
246 | goto out_hfsn; | |
247 | } | |
248 | ||
249 | group->private = hfsn; | |
250 | hfsn->hfsn_group = group; | |
251 | br->br_hfsn = hfsn; | |
252 | goto out; /* success */ | |
253 | ||
254 | out_hfsn: | |
255 | kfree(hfsn); | |
256 | out: | |
257 | return err; | |
258 | } | |
259 | ||
260 | static int au_hfsn_reset_br(unsigned int udba, struct au_branch *br, int perm) | |
261 | { | |
262 | int err; | |
263 | ||
264 | err = 0; | |
265 | if (!br->br_hfsn) | |
266 | err = au_hfsn_init_br(br, perm); | |
267 | ||
268 | return err; | |
269 | } | |
270 | ||
271 | /* ---------------------------------------------------------------------- */ | |
272 | ||
273 | static void au_hfsn_fin(void) | |
274 | { | |
275 | AuDbg("au_hfsn_ifree %lld\n", (long long)atomic64_read(&au_hfsn_ifree)); | |
276 | wait_event(au_hfsn_wq, !atomic64_read(&au_hfsn_ifree)); | |
277 | } | |
278 | ||
279 | const struct au_hnotify_op au_hnotify_op = { | |
280 | .ctl = au_hfsn_ctl, | |
281 | .alloc = au_hfsn_alloc, | |
282 | .free = au_hfsn_free, | |
283 | ||
284 | .fin = au_hfsn_fin, | |
285 | ||
286 | .reset_br = au_hfsn_reset_br, | |
287 | .fin_br = au_hfsn_fin_br, | |
288 | .init_br = au_hfsn_init_br | |
289 | }; |