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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
e9be9d5e MS |
2 | /* |
3 | * | |
4 | * Copyright (C) 2011 Novell Inc. | |
e9be9d5e MS |
5 | */ |
6 | ||
5b825c3a | 7 | #include <uapi/linux/magic.h> |
e9be9d5e MS |
8 | #include <linux/fs.h> |
9 | #include <linux/namei.h> | |
10 | #include <linux/xattr.h> | |
e9be9d5e | 11 | #include <linux/mount.h> |
e9be9d5e MS |
12 | #include <linux/parser.h> |
13 | #include <linux/module.h> | |
cc259639 | 14 | #include <linux/statfs.h> |
f45827e8 | 15 | #include <linux/seq_file.h> |
d837a49b | 16 | #include <linux/posix_acl_xattr.h> |
e487d889 | 17 | #include <linux/exportfs.h> |
e9be9d5e MS |
18 | #include "overlayfs.h" |
19 | ||
20 | MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); | |
21 | MODULE_DESCRIPTION("Overlay filesystem"); | |
22 | MODULE_LICENSE("GPL"); | |
23 | ||
e9be9d5e MS |
24 | |
25 | struct ovl_dir_cache; | |
26 | ||
a78d9f0d MS |
27 | #define OVL_MAX_STACK 500 |
28 | ||
688ea0e5 MS |
29 | static bool ovl_redirect_dir_def = IS_ENABLED(CONFIG_OVERLAY_FS_REDIRECT_DIR); |
30 | module_param_named(redirect_dir, ovl_redirect_dir_def, bool, 0644); | |
253e7483 | 31 | MODULE_PARM_DESC(redirect_dir, |
688ea0e5 | 32 | "Default to on or off for the redirect_dir feature"); |
e9be9d5e | 33 | |
438c84c2 MS |
34 | static bool ovl_redirect_always_follow = |
35 | IS_ENABLED(CONFIG_OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW); | |
36 | module_param_named(redirect_always_follow, ovl_redirect_always_follow, | |
37 | bool, 0644); | |
253e7483 | 38 | MODULE_PARM_DESC(redirect_always_follow, |
438c84c2 MS |
39 | "Follow redirects even if redirect_dir feature is turned off"); |
40 | ||
02bcd157 AG |
41 | static bool ovl_index_def = IS_ENABLED(CONFIG_OVERLAY_FS_INDEX); |
42 | module_param_named(index, ovl_index_def, bool, 0644); | |
253e7483 | 43 | MODULE_PARM_DESC(index, |
02bcd157 AG |
44 | "Default to on or off for the inodes index feature"); |
45 | ||
f168f109 AG |
46 | static bool ovl_nfs_export_def = IS_ENABLED(CONFIG_OVERLAY_FS_NFS_EXPORT); |
47 | module_param_named(nfs_export, ovl_nfs_export_def, bool, 0644); | |
253e7483 | 48 | MODULE_PARM_DESC(nfs_export, |
f168f109 AG |
49 | "Default to on or off for the NFS export feature"); |
50 | ||
795939a9 AG |
51 | static bool ovl_xino_auto_def = IS_ENABLED(CONFIG_OVERLAY_FS_XINO_AUTO); |
52 | module_param_named(xino_auto, ovl_xino_auto_def, bool, 0644); | |
253e7483 | 53 | MODULE_PARM_DESC(xino_auto, |
795939a9 AG |
54 | "Auto enable xino feature"); |
55 | ||
4155c10a MS |
56 | static void ovl_entry_stack_free(struct ovl_entry *oe) |
57 | { | |
58 | unsigned int i; | |
59 | ||
60 | for (i = 0; i < oe->numlower; i++) | |
61 | dput(oe->lowerstack[i].dentry); | |
62 | } | |
63 | ||
d5791044 VG |
64 | static bool ovl_metacopy_def = IS_ENABLED(CONFIG_OVERLAY_FS_METACOPY); |
65 | module_param_named(metacopy, ovl_metacopy_def, bool, 0644); | |
253e7483 | 66 | MODULE_PARM_DESC(metacopy, |
d5791044 VG |
67 | "Default to on or off for the metadata only copy up feature"); |
68 | ||
e9be9d5e MS |
69 | static void ovl_dentry_release(struct dentry *dentry) |
70 | { | |
71 | struct ovl_entry *oe = dentry->d_fsdata; | |
72 | ||
73 | if (oe) { | |
4155c10a | 74 | ovl_entry_stack_free(oe); |
e9be9d5e MS |
75 | kfree_rcu(oe, rcu); |
76 | } | |
77 | } | |
78 | ||
2d902671 | 79 | static struct dentry *ovl_d_real(struct dentry *dentry, |
fb16043b | 80 | const struct inode *inode) |
d101a125 MS |
81 | { |
82 | struct dentry *real; | |
83 | ||
e8c985ba MS |
84 | /* It's an overlay file */ |
85 | if (inode && d_inode(dentry) == inode) | |
86 | return dentry; | |
87 | ||
ca4c8a3a | 88 | if (!d_is_reg(dentry)) { |
d101a125 MS |
89 | if (!inode || inode == d_inode(dentry)) |
90 | return dentry; | |
91 | goto bug; | |
92 | } | |
93 | ||
94 | real = ovl_dentry_upper(dentry); | |
2c3d7358 | 95 | if (real && (inode == d_inode(real))) |
d101a125 MS |
96 | return real; |
97 | ||
2c3d7358 VG |
98 | if (real && !inode && ovl_has_upperdata(d_inode(dentry))) |
99 | return real; | |
100 | ||
101 | real = ovl_dentry_lowerdata(dentry); | |
d101a125 MS |
102 | if (!real) |
103 | goto bug; | |
104 | ||
c4fcfc16 | 105 | /* Handle recursion */ |
fb16043b | 106 | real = d_real(real, inode); |
c4fcfc16 | 107 | |
d101a125 MS |
108 | if (!inode || inode == d_inode(real)) |
109 | return real; | |
d101a125 | 110 | bug: |
656189d2 | 111 | WARN(1, "ovl_d_real(%pd4, %s:%lu): real dentry not found\n", dentry, |
d101a125 MS |
112 | inode ? inode->i_sb->s_id : "NULL", inode ? inode->i_ino : 0); |
113 | return dentry; | |
114 | } | |
115 | ||
3bb7df92 | 116 | static int ovl_revalidate_real(struct dentry *d, unsigned int flags, bool weak) |
7c03b5d4 | 117 | { |
7c03b5d4 MS |
118 | int ret = 1; |
119 | ||
3bb7df92 MS |
120 | if (weak) { |
121 | if (d->d_flags & DCACHE_OP_WEAK_REVALIDATE) | |
122 | ret = d->d_op->d_weak_revalidate(d, flags); | |
123 | } else if (d->d_flags & DCACHE_OP_REVALIDATE) { | |
124 | ret = d->d_op->d_revalidate(d, flags); | |
125 | if (!ret) { | |
126 | if (!(flags & LOOKUP_RCU)) | |
127 | d_invalidate(d); | |
128 | ret = -ESTALE; | |
7c03b5d4 MS |
129 | } |
130 | } | |
3bb7df92 | 131 | return ret; |
7c03b5d4 MS |
132 | } |
133 | ||
3bb7df92 MS |
134 | static int ovl_dentry_revalidate_common(struct dentry *dentry, |
135 | unsigned int flags, bool weak) | |
7c03b5d4 MS |
136 | { |
137 | struct ovl_entry *oe = dentry->d_fsdata; | |
bccece1e | 138 | struct dentry *upper; |
7c03b5d4 MS |
139 | unsigned int i; |
140 | int ret = 1; | |
141 | ||
bccece1e MS |
142 | upper = ovl_dentry_upper(dentry); |
143 | if (upper) | |
144 | ret = ovl_revalidate_real(upper, flags, weak); | |
145 | ||
3bb7df92 MS |
146 | for (i = 0; ret > 0 && i < oe->numlower; i++) { |
147 | ret = ovl_revalidate_real(oe->lowerstack[i].dentry, flags, | |
148 | weak); | |
7c03b5d4 MS |
149 | } |
150 | return ret; | |
151 | } | |
152 | ||
3bb7df92 MS |
153 | static int ovl_dentry_revalidate(struct dentry *dentry, unsigned int flags) |
154 | { | |
155 | return ovl_dentry_revalidate_common(dentry, flags, false); | |
156 | } | |
157 | ||
158 | static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags) | |
159 | { | |
160 | return ovl_dentry_revalidate_common(dentry, flags, true); | |
161 | } | |
162 | ||
e9be9d5e MS |
163 | static const struct dentry_operations ovl_dentry_operations = { |
164 | .d_release = ovl_dentry_release, | |
d101a125 | 165 | .d_real = ovl_d_real, |
7c03b5d4 MS |
166 | .d_revalidate = ovl_dentry_revalidate, |
167 | .d_weak_revalidate = ovl_dentry_weak_revalidate, | |
168 | }; | |
169 | ||
13cf199d AG |
170 | static struct kmem_cache *ovl_inode_cachep; |
171 | ||
172 | static struct inode *ovl_alloc_inode(struct super_block *sb) | |
173 | { | |
174 | struct ovl_inode *oi = kmem_cache_alloc(ovl_inode_cachep, GFP_KERNEL); | |
175 | ||
b3885bd6 HN |
176 | if (!oi) |
177 | return NULL; | |
178 | ||
04a01ac7 | 179 | oi->cache = NULL; |
cf31c463 | 180 | oi->redirect = NULL; |
04a01ac7 | 181 | oi->version = 0; |
13c72075 | 182 | oi->flags = 0; |
09d8b586 | 183 | oi->__upperdentry = NULL; |
25b7713a | 184 | oi->lower = NULL; |
2664bd08 | 185 | oi->lowerdata = NULL; |
a015dafc | 186 | mutex_init(&oi->lock); |
25b7713a | 187 | |
13cf199d AG |
188 | return &oi->vfs_inode; |
189 | } | |
190 | ||
0b269ded | 191 | static void ovl_free_inode(struct inode *inode) |
13cf199d | 192 | { |
0b269ded | 193 | struct ovl_inode *oi = OVL_I(inode); |
13cf199d | 194 | |
0b269ded AV |
195 | kfree(oi->redirect); |
196 | mutex_destroy(&oi->lock); | |
197 | kmem_cache_free(ovl_inode_cachep, oi); | |
13cf199d AG |
198 | } |
199 | ||
200 | static void ovl_destroy_inode(struct inode *inode) | |
201 | { | |
09d8b586 MS |
202 | struct ovl_inode *oi = OVL_I(inode); |
203 | ||
204 | dput(oi->__upperdentry); | |
31747eda | 205 | iput(oi->lower); |
2664bd08 VG |
206 | if (S_ISDIR(inode->i_mode)) |
207 | ovl_dir_cache_free(inode); | |
208 | else | |
209 | iput(oi->lowerdata); | |
13cf199d AG |
210 | } |
211 | ||
ad204488 | 212 | static void ovl_free_fs(struct ovl_fs *ofs) |
e9be9d5e | 213 | { |
dd662667 | 214 | unsigned i; |
e9be9d5e | 215 | |
0be0bfd2 | 216 | iput(ofs->workbasedir_trap); |
146d62e5 AG |
217 | iput(ofs->indexdir_trap); |
218 | iput(ofs->workdir_trap); | |
219 | iput(ofs->upperdir_trap); | |
c21c839b | 220 | dput(ofs->whiteout); |
ad204488 MS |
221 | dput(ofs->indexdir); |
222 | dput(ofs->workdir); | |
223 | if (ofs->workdir_locked) | |
224 | ovl_inuse_unlock(ofs->workbasedir); | |
225 | dput(ofs->workbasedir); | |
226 | if (ofs->upperdir_locked) | |
227 | ovl_inuse_unlock(ofs->upper_mnt->mnt_root); | |
228 | mntput(ofs->upper_mnt); | |
94375f9d AG |
229 | for (i = 1; i < ofs->numlayer; i++) { |
230 | iput(ofs->layers[i].trap); | |
231 | mntput(ofs->layers[i].mnt); | |
146d62e5 | 232 | } |
94375f9d | 233 | kfree(ofs->layers); |
b7bf9908 | 234 | for (i = 0; i < ofs->numfs; i++) |
07f1e596 AG |
235 | free_anon_bdev(ofs->fs[i].pseudo_dev); |
236 | kfree(ofs->fs); | |
ad204488 MS |
237 | |
238 | kfree(ofs->config.lowerdir); | |
239 | kfree(ofs->config.upperdir); | |
240 | kfree(ofs->config.workdir); | |
438c84c2 | 241 | kfree(ofs->config.redirect_mode); |
ad204488 MS |
242 | if (ofs->creator_cred) |
243 | put_cred(ofs->creator_cred); | |
244 | kfree(ofs); | |
e9be9d5e MS |
245 | } |
246 | ||
a9075cdb MS |
247 | static void ovl_put_super(struct super_block *sb) |
248 | { | |
249 | struct ovl_fs *ofs = sb->s_fs_info; | |
250 | ||
251 | ovl_free_fs(ofs); | |
252 | } | |
253 | ||
e8d4bfe3 | 254 | /* Sync real dirty inodes in upper filesystem (if it exists) */ |
e593b2bf AG |
255 | static int ovl_sync_fs(struct super_block *sb, int wait) |
256 | { | |
ad204488 | 257 | struct ovl_fs *ofs = sb->s_fs_info; |
e593b2bf AG |
258 | struct super_block *upper_sb; |
259 | int ret; | |
260 | ||
ad204488 | 261 | if (!ofs->upper_mnt) |
e593b2bf | 262 | return 0; |
e8d4bfe3 CX |
263 | |
264 | /* | |
32b1924b KK |
265 | * Not called for sync(2) call or an emergency sync (SB_I_SKIP_SYNC). |
266 | * All the super blocks will be iterated, including upper_sb. | |
e8d4bfe3 CX |
267 | * |
268 | * If this is a syncfs(2) call, then we do need to call | |
269 | * sync_filesystem() on upper_sb, but enough if we do it when being | |
270 | * called with wait == 1. | |
271 | */ | |
272 | if (!wait) | |
e593b2bf AG |
273 | return 0; |
274 | ||
e8d4bfe3 CX |
275 | upper_sb = ofs->upper_mnt->mnt_sb; |
276 | ||
e593b2bf | 277 | down_read(&upper_sb->s_umount); |
e8d4bfe3 | 278 | ret = sync_filesystem(upper_sb); |
e593b2bf | 279 | up_read(&upper_sb->s_umount); |
e8d4bfe3 | 280 | |
e593b2bf AG |
281 | return ret; |
282 | } | |
283 | ||
cc259639 AW |
284 | /** |
285 | * ovl_statfs | |
286 | * @sb: The overlayfs super block | |
287 | * @buf: The struct kstatfs to fill in with stats | |
288 | * | |
289 | * Get the filesystem statistics. As writes always target the upper layer | |
4ebc5818 | 290 | * filesystem pass the statfs to the upper filesystem (if it exists) |
cc259639 AW |
291 | */ |
292 | static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf) | |
293 | { | |
294 | struct ovl_fs *ofs = dentry->d_sb->s_fs_info; | |
295 | struct dentry *root_dentry = dentry->d_sb->s_root; | |
296 | struct path path; | |
297 | int err; | |
298 | ||
4ebc5818 | 299 | ovl_path_real(root_dentry, &path); |
cc259639 AW |
300 | |
301 | err = vfs_statfs(&path, buf); | |
302 | if (!err) { | |
6b2d5fe4 | 303 | buf->f_namelen = ofs->namelen; |
cc259639 AW |
304 | buf->f_type = OVERLAYFS_SUPER_MAGIC; |
305 | } | |
306 | ||
307 | return err; | |
308 | } | |
309 | ||
02bcd157 | 310 | /* Will this overlay be forced to mount/remount ro? */ |
ad204488 | 311 | static bool ovl_force_readonly(struct ovl_fs *ofs) |
02bcd157 | 312 | { |
ad204488 | 313 | return (!ofs->upper_mnt || !ofs->workdir); |
02bcd157 AG |
314 | } |
315 | ||
438c84c2 MS |
316 | static const char *ovl_redirect_mode_def(void) |
317 | { | |
318 | return ovl_redirect_dir_def ? "on" : "off"; | |
319 | } | |
320 | ||
795939a9 AG |
321 | static const char * const ovl_xino_str[] = { |
322 | "off", | |
323 | "auto", | |
324 | "on", | |
325 | }; | |
326 | ||
327 | static inline int ovl_xino_def(void) | |
328 | { | |
329 | return ovl_xino_auto_def ? OVL_XINO_AUTO : OVL_XINO_OFF; | |
330 | } | |
331 | ||
f45827e8 EZ |
332 | /** |
333 | * ovl_show_options | |
334 | * | |
335 | * Prints the mount options for a given superblock. | |
336 | * Returns zero; does not fail. | |
337 | */ | |
338 | static int ovl_show_options(struct seq_file *m, struct dentry *dentry) | |
339 | { | |
340 | struct super_block *sb = dentry->d_sb; | |
ad204488 | 341 | struct ovl_fs *ofs = sb->s_fs_info; |
f45827e8 | 342 | |
ad204488 MS |
343 | seq_show_option(m, "lowerdir", ofs->config.lowerdir); |
344 | if (ofs->config.upperdir) { | |
345 | seq_show_option(m, "upperdir", ofs->config.upperdir); | |
346 | seq_show_option(m, "workdir", ofs->config.workdir); | |
53a08cb9 | 347 | } |
ad204488 | 348 | if (ofs->config.default_permissions) |
8d3095f4 | 349 | seq_puts(m, ",default_permissions"); |
438c84c2 MS |
350 | if (strcmp(ofs->config.redirect_mode, ovl_redirect_mode_def()) != 0) |
351 | seq_printf(m, ",redirect_dir=%s", ofs->config.redirect_mode); | |
ad204488 | 352 | if (ofs->config.index != ovl_index_def) |
438c84c2 | 353 | seq_printf(m, ",index=%s", ofs->config.index ? "on" : "off"); |
f168f109 AG |
354 | if (ofs->config.nfs_export != ovl_nfs_export_def) |
355 | seq_printf(m, ",nfs_export=%s", ofs->config.nfs_export ? | |
356 | "on" : "off"); | |
0f831ec8 | 357 | if (ofs->config.xino != ovl_xino_def() && !ovl_same_fs(sb)) |
795939a9 | 358 | seq_printf(m, ",xino=%s", ovl_xino_str[ofs->config.xino]); |
d5791044 VG |
359 | if (ofs->config.metacopy != ovl_metacopy_def) |
360 | seq_printf(m, ",metacopy=%s", | |
361 | ofs->config.metacopy ? "on" : "off"); | |
f45827e8 EZ |
362 | return 0; |
363 | } | |
364 | ||
3cdf6fe9 SL |
365 | static int ovl_remount(struct super_block *sb, int *flags, char *data) |
366 | { | |
ad204488 | 367 | struct ovl_fs *ofs = sb->s_fs_info; |
399c109d CX |
368 | struct super_block *upper_sb; |
369 | int ret = 0; | |
3cdf6fe9 | 370 | |
1751e8a6 | 371 | if (!(*flags & SB_RDONLY) && ovl_force_readonly(ofs)) |
3cdf6fe9 SL |
372 | return -EROFS; |
373 | ||
399c109d CX |
374 | if (*flags & SB_RDONLY && !sb_rdonly(sb)) { |
375 | upper_sb = ofs->upper_mnt->mnt_sb; | |
376 | down_read(&upper_sb->s_umount); | |
377 | ret = sync_filesystem(upper_sb); | |
378 | up_read(&upper_sb->s_umount); | |
379 | } | |
380 | ||
381 | return ret; | |
3cdf6fe9 SL |
382 | } |
383 | ||
e9be9d5e | 384 | static const struct super_operations ovl_super_operations = { |
13cf199d | 385 | .alloc_inode = ovl_alloc_inode, |
0b269ded | 386 | .free_inode = ovl_free_inode, |
13cf199d AG |
387 | .destroy_inode = ovl_destroy_inode, |
388 | .drop_inode = generic_delete_inode, | |
e9be9d5e | 389 | .put_super = ovl_put_super, |
e593b2bf | 390 | .sync_fs = ovl_sync_fs, |
cc259639 | 391 | .statfs = ovl_statfs, |
f45827e8 | 392 | .show_options = ovl_show_options, |
3cdf6fe9 | 393 | .remount_fs = ovl_remount, |
e9be9d5e MS |
394 | }; |
395 | ||
396 | enum { | |
397 | OPT_LOWERDIR, | |
398 | OPT_UPPERDIR, | |
399 | OPT_WORKDIR, | |
8d3095f4 | 400 | OPT_DEFAULT_PERMISSIONS, |
438c84c2 | 401 | OPT_REDIRECT_DIR, |
02bcd157 AG |
402 | OPT_INDEX_ON, |
403 | OPT_INDEX_OFF, | |
f168f109 AG |
404 | OPT_NFS_EXPORT_ON, |
405 | OPT_NFS_EXPORT_OFF, | |
795939a9 AG |
406 | OPT_XINO_ON, |
407 | OPT_XINO_OFF, | |
408 | OPT_XINO_AUTO, | |
d5791044 VG |
409 | OPT_METACOPY_ON, |
410 | OPT_METACOPY_OFF, | |
e9be9d5e MS |
411 | OPT_ERR, |
412 | }; | |
413 | ||
414 | static const match_table_t ovl_tokens = { | |
415 | {OPT_LOWERDIR, "lowerdir=%s"}, | |
416 | {OPT_UPPERDIR, "upperdir=%s"}, | |
417 | {OPT_WORKDIR, "workdir=%s"}, | |
8d3095f4 | 418 | {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, |
438c84c2 | 419 | {OPT_REDIRECT_DIR, "redirect_dir=%s"}, |
02bcd157 AG |
420 | {OPT_INDEX_ON, "index=on"}, |
421 | {OPT_INDEX_OFF, "index=off"}, | |
f168f109 AG |
422 | {OPT_NFS_EXPORT_ON, "nfs_export=on"}, |
423 | {OPT_NFS_EXPORT_OFF, "nfs_export=off"}, | |
795939a9 AG |
424 | {OPT_XINO_ON, "xino=on"}, |
425 | {OPT_XINO_OFF, "xino=off"}, | |
426 | {OPT_XINO_AUTO, "xino=auto"}, | |
d5791044 VG |
427 | {OPT_METACOPY_ON, "metacopy=on"}, |
428 | {OPT_METACOPY_OFF, "metacopy=off"}, | |
e9be9d5e MS |
429 | {OPT_ERR, NULL} |
430 | }; | |
431 | ||
91c77947 MS |
432 | static char *ovl_next_opt(char **s) |
433 | { | |
434 | char *sbegin = *s; | |
435 | char *p; | |
436 | ||
437 | if (sbegin == NULL) | |
438 | return NULL; | |
439 | ||
440 | for (p = sbegin; *p; p++) { | |
441 | if (*p == '\\') { | |
442 | p++; | |
443 | if (!*p) | |
444 | break; | |
445 | } else if (*p == ',') { | |
446 | *p = '\0'; | |
447 | *s = p + 1; | |
448 | return sbegin; | |
449 | } | |
450 | } | |
451 | *s = NULL; | |
452 | return sbegin; | |
453 | } | |
454 | ||
438c84c2 MS |
455 | static int ovl_parse_redirect_mode(struct ovl_config *config, const char *mode) |
456 | { | |
457 | if (strcmp(mode, "on") == 0) { | |
458 | config->redirect_dir = true; | |
459 | /* | |
460 | * Does not make sense to have redirect creation without | |
461 | * redirect following. | |
462 | */ | |
463 | config->redirect_follow = true; | |
464 | } else if (strcmp(mode, "follow") == 0) { | |
465 | config->redirect_follow = true; | |
466 | } else if (strcmp(mode, "off") == 0) { | |
467 | if (ovl_redirect_always_follow) | |
468 | config->redirect_follow = true; | |
469 | } else if (strcmp(mode, "nofollow") != 0) { | |
1bd0a3ae | 470 | pr_err("bad mount option \"redirect_dir=%s\"\n", |
438c84c2 MS |
471 | mode); |
472 | return -EINVAL; | |
473 | } | |
474 | ||
475 | return 0; | |
476 | } | |
477 | ||
e9be9d5e MS |
478 | static int ovl_parse_opt(char *opt, struct ovl_config *config) |
479 | { | |
480 | char *p; | |
d5791044 | 481 | int err; |
d47748e5 | 482 | bool metacopy_opt = false, redirect_opt = false; |
b0def88d | 483 | bool nfs_export_opt = false, index_opt = false; |
e9be9d5e | 484 | |
438c84c2 MS |
485 | config->redirect_mode = kstrdup(ovl_redirect_mode_def(), GFP_KERNEL); |
486 | if (!config->redirect_mode) | |
487 | return -ENOMEM; | |
488 | ||
91c77947 | 489 | while ((p = ovl_next_opt(&opt)) != NULL) { |
e9be9d5e MS |
490 | int token; |
491 | substring_t args[MAX_OPT_ARGS]; | |
492 | ||
493 | if (!*p) | |
494 | continue; | |
495 | ||
496 | token = match_token(p, ovl_tokens, args); | |
497 | switch (token) { | |
498 | case OPT_UPPERDIR: | |
499 | kfree(config->upperdir); | |
500 | config->upperdir = match_strdup(&args[0]); | |
501 | if (!config->upperdir) | |
502 | return -ENOMEM; | |
503 | break; | |
504 | ||
505 | case OPT_LOWERDIR: | |
506 | kfree(config->lowerdir); | |
507 | config->lowerdir = match_strdup(&args[0]); | |
508 | if (!config->lowerdir) | |
509 | return -ENOMEM; | |
510 | break; | |
511 | ||
512 | case OPT_WORKDIR: | |
513 | kfree(config->workdir); | |
514 | config->workdir = match_strdup(&args[0]); | |
515 | if (!config->workdir) | |
516 | return -ENOMEM; | |
517 | break; | |
518 | ||
8d3095f4 MS |
519 | case OPT_DEFAULT_PERMISSIONS: |
520 | config->default_permissions = true; | |
521 | break; | |
522 | ||
438c84c2 MS |
523 | case OPT_REDIRECT_DIR: |
524 | kfree(config->redirect_mode); | |
525 | config->redirect_mode = match_strdup(&args[0]); | |
526 | if (!config->redirect_mode) | |
527 | return -ENOMEM; | |
d47748e5 | 528 | redirect_opt = true; |
a6c60655 MS |
529 | break; |
530 | ||
02bcd157 AG |
531 | case OPT_INDEX_ON: |
532 | config->index = true; | |
b0def88d | 533 | index_opt = true; |
02bcd157 AG |
534 | break; |
535 | ||
536 | case OPT_INDEX_OFF: | |
537 | config->index = false; | |
b0def88d | 538 | index_opt = true; |
02bcd157 AG |
539 | break; |
540 | ||
f168f109 AG |
541 | case OPT_NFS_EXPORT_ON: |
542 | config->nfs_export = true; | |
b0def88d | 543 | nfs_export_opt = true; |
f168f109 AG |
544 | break; |
545 | ||
546 | case OPT_NFS_EXPORT_OFF: | |
547 | config->nfs_export = false; | |
b0def88d | 548 | nfs_export_opt = true; |
f168f109 AG |
549 | break; |
550 | ||
795939a9 AG |
551 | case OPT_XINO_ON: |
552 | config->xino = OVL_XINO_ON; | |
553 | break; | |
554 | ||
555 | case OPT_XINO_OFF: | |
556 | config->xino = OVL_XINO_OFF; | |
557 | break; | |
558 | ||
559 | case OPT_XINO_AUTO: | |
560 | config->xino = OVL_XINO_AUTO; | |
561 | break; | |
562 | ||
d5791044 VG |
563 | case OPT_METACOPY_ON: |
564 | config->metacopy = true; | |
d47748e5 | 565 | metacopy_opt = true; |
d5791044 VG |
566 | break; |
567 | ||
568 | case OPT_METACOPY_OFF: | |
569 | config->metacopy = false; | |
b0def88d | 570 | metacopy_opt = true; |
d5791044 VG |
571 | break; |
572 | ||
e9be9d5e | 573 | default: |
1bd0a3ae | 574 | pr_err("unrecognized mount option \"%s\" or missing value\n", |
575 | p); | |
e9be9d5e MS |
576 | return -EINVAL; |
577 | } | |
578 | } | |
71cbad7e | 579 | |
580 | /* Workdir is useless in non-upper mount */ | |
581 | if (!config->upperdir && config->workdir) { | |
1bd0a3ae | 582 | pr_info("option \"workdir=%s\" is useless in a non-upper mount, ignore\n", |
71cbad7e | 583 | config->workdir); |
584 | kfree(config->workdir); | |
585 | config->workdir = NULL; | |
586 | } | |
587 | ||
d5791044 VG |
588 | err = ovl_parse_redirect_mode(config, config->redirect_mode); |
589 | if (err) | |
590 | return err; | |
591 | ||
d47748e5 MS |
592 | /* |
593 | * This is to make the logic below simpler. It doesn't make any other | |
594 | * difference, since config->redirect_dir is only used for upper. | |
595 | */ | |
596 | if (!config->upperdir && config->redirect_follow) | |
597 | config->redirect_dir = true; | |
598 | ||
599 | /* Resolve metacopy -> redirect_dir dependency */ | |
600 | if (config->metacopy && !config->redirect_dir) { | |
601 | if (metacopy_opt && redirect_opt) { | |
1bd0a3ae | 602 | pr_err("conflicting options: metacopy=on,redirect_dir=%s\n", |
d47748e5 MS |
603 | config->redirect_mode); |
604 | return -EINVAL; | |
605 | } | |
606 | if (redirect_opt) { | |
607 | /* | |
608 | * There was an explicit redirect_dir=... that resulted | |
609 | * in this conflict. | |
610 | */ | |
1bd0a3ae | 611 | pr_info("disabling metacopy due to redirect_dir=%s\n", |
d47748e5 MS |
612 | config->redirect_mode); |
613 | config->metacopy = false; | |
614 | } else { | |
615 | /* Automatically enable redirect otherwise. */ | |
616 | config->redirect_follow = config->redirect_dir = true; | |
617 | } | |
d5791044 VG |
618 | } |
619 | ||
b0def88d AG |
620 | /* Resolve nfs_export -> index dependency */ |
621 | if (config->nfs_export && !config->index) { | |
622 | if (nfs_export_opt && index_opt) { | |
623 | pr_err("conflicting options: nfs_export=on,index=off\n"); | |
624 | return -EINVAL; | |
625 | } | |
626 | if (index_opt) { | |
627 | /* | |
628 | * There was an explicit index=off that resulted | |
629 | * in this conflict. | |
630 | */ | |
631 | pr_info("disabling nfs_export due to index=off\n"); | |
632 | config->nfs_export = false; | |
633 | } else { | |
634 | /* Automatically enable index otherwise. */ | |
635 | config->index = true; | |
636 | } | |
637 | } | |
638 | ||
639 | /* Resolve nfs_export -> !metacopy dependency */ | |
640 | if (config->nfs_export && config->metacopy) { | |
641 | if (nfs_export_opt && metacopy_opt) { | |
642 | pr_err("conflicting options: nfs_export=on,metacopy=on\n"); | |
643 | return -EINVAL; | |
644 | } | |
645 | if (metacopy_opt) { | |
646 | /* | |
647 | * There was an explicit metacopy=on that resulted | |
648 | * in this conflict. | |
649 | */ | |
650 | pr_info("disabling nfs_export due to metacopy=on\n"); | |
651 | config->nfs_export = false; | |
652 | } else { | |
653 | /* | |
654 | * There was an explicit nfs_export=on that resulted | |
655 | * in this conflict. | |
656 | */ | |
657 | pr_info("disabling metacopy due to nfs_export=on\n"); | |
658 | config->metacopy = false; | |
659 | } | |
660 | } | |
661 | ||
d5791044 | 662 | return 0; |
e9be9d5e MS |
663 | } |
664 | ||
665 | #define OVL_WORKDIR_NAME "work" | |
02bcd157 | 666 | #define OVL_INDEXDIR_NAME "index" |
e9be9d5e | 667 | |
ad204488 | 668 | static struct dentry *ovl_workdir_create(struct ovl_fs *ofs, |
6b8aa129 | 669 | const char *name, bool persist) |
e9be9d5e | 670 | { |
ad204488 MS |
671 | struct inode *dir = ofs->workbasedir->d_inode; |
672 | struct vfsmount *mnt = ofs->upper_mnt; | |
e9be9d5e MS |
673 | struct dentry *work; |
674 | int err; | |
675 | bool retried = false; | |
6b8aa129 | 676 | bool locked = false; |
e9be9d5e | 677 | |
5955102c | 678 | inode_lock_nested(dir, I_MUTEX_PARENT); |
6b8aa129 AG |
679 | locked = true; |
680 | ||
e9be9d5e | 681 | retry: |
ad204488 | 682 | work = lookup_one_len(name, ofs->workbasedir, strlen(name)); |
e9be9d5e MS |
683 | |
684 | if (!IS_ERR(work)) { | |
c11b9fdd MS |
685 | struct iattr attr = { |
686 | .ia_valid = ATTR_MODE, | |
32a3d848 | 687 | .ia_mode = S_IFDIR | 0, |
c11b9fdd | 688 | }; |
e9be9d5e MS |
689 | |
690 | if (work->d_inode) { | |
691 | err = -EEXIST; | |
692 | if (retried) | |
693 | goto out_dput; | |
694 | ||
6b8aa129 AG |
695 | if (persist) |
696 | goto out_unlock; | |
697 | ||
e9be9d5e | 698 | retried = true; |
eea2fb48 | 699 | ovl_workdir_cleanup(dir, mnt, work, 0); |
e9be9d5e MS |
700 | dput(work); |
701 | goto retry; | |
702 | } | |
703 | ||
95a1c815 MS |
704 | work = ovl_create_real(dir, work, OVL_CATTR(attr.ia_mode)); |
705 | err = PTR_ERR(work); | |
706 | if (IS_ERR(work)) | |
707 | goto out_err; | |
c11b9fdd | 708 | |
cb348edb MS |
709 | /* |
710 | * Try to remove POSIX ACL xattrs from workdir. We are good if: | |
711 | * | |
712 | * a) success (there was a POSIX ACL xattr and was removed) | |
713 | * b) -ENODATA (there was no POSIX ACL xattr) | |
714 | * c) -EOPNOTSUPP (POSIX ACL xattrs are not supported) | |
715 | * | |
716 | * There are various other error values that could effectively | |
717 | * mean that the xattr doesn't exist (e.g. -ERANGE is returned | |
718 | * if the xattr name is too long), but the set of filesystems | |
719 | * allowed as upper are limited to "normal" ones, where checking | |
720 | * for the above two errors is sufficient. | |
721 | */ | |
c11b9fdd | 722 | err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT); |
e1ff3dd1 | 723 | if (err && err != -ENODATA && err != -EOPNOTSUPP) |
c11b9fdd MS |
724 | goto out_dput; |
725 | ||
726 | err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_ACCESS); | |
e1ff3dd1 | 727 | if (err && err != -ENODATA && err != -EOPNOTSUPP) |
c11b9fdd MS |
728 | goto out_dput; |
729 | ||
730 | /* Clear any inherited mode bits */ | |
731 | inode_lock(work->d_inode); | |
732 | err = notify_change(work, &attr, NULL); | |
733 | inode_unlock(work->d_inode); | |
734 | if (err) | |
735 | goto out_dput; | |
6b8aa129 AG |
736 | } else { |
737 | err = PTR_ERR(work); | |
738 | goto out_err; | |
e9be9d5e MS |
739 | } |
740 | out_unlock: | |
6b8aa129 AG |
741 | if (locked) |
742 | inode_unlock(dir); | |
e9be9d5e MS |
743 | |
744 | return work; | |
745 | ||
746 | out_dput: | |
747 | dput(work); | |
6b8aa129 | 748 | out_err: |
1bd0a3ae | 749 | pr_warn("failed to create directory %s/%s (errno: %i); mounting read-only\n", |
ad204488 | 750 | ofs->config.workdir, name, -err); |
6b8aa129 | 751 | work = NULL; |
e9be9d5e MS |
752 | goto out_unlock; |
753 | } | |
754 | ||
91c77947 MS |
755 | static void ovl_unescape(char *s) |
756 | { | |
757 | char *d = s; | |
758 | ||
759 | for (;; s++, d++) { | |
760 | if (*s == '\\') | |
761 | s++; | |
762 | *d = *s; | |
763 | if (!*s) | |
764 | break; | |
765 | } | |
766 | } | |
767 | ||
ab508822 MS |
768 | static int ovl_mount_dir_noesc(const char *name, struct path *path) |
769 | { | |
a78d9f0d | 770 | int err = -EINVAL; |
ab508822 | 771 | |
a78d9f0d | 772 | if (!*name) { |
1bd0a3ae | 773 | pr_err("empty lowerdir\n"); |
a78d9f0d MS |
774 | goto out; |
775 | } | |
ab508822 MS |
776 | err = kern_path(name, LOOKUP_FOLLOW, path); |
777 | if (err) { | |
1bd0a3ae | 778 | pr_err("failed to resolve '%s': %i\n", name, err); |
ab508822 MS |
779 | goto out; |
780 | } | |
781 | err = -EINVAL; | |
7c03b5d4 | 782 | if (ovl_dentry_weird(path->dentry)) { |
1bd0a3ae | 783 | pr_err("filesystem on '%s' not supported\n", name); |
ab508822 MS |
784 | goto out_put; |
785 | } | |
2b8c30e9 | 786 | if (!d_is_dir(path->dentry)) { |
1bd0a3ae | 787 | pr_err("'%s' not a directory\n", name); |
ab508822 MS |
788 | goto out_put; |
789 | } | |
790 | return 0; | |
791 | ||
792 | out_put: | |
8aafcb59 | 793 | path_put_init(path); |
ab508822 MS |
794 | out: |
795 | return err; | |
796 | } | |
797 | ||
798 | static int ovl_mount_dir(const char *name, struct path *path) | |
799 | { | |
800 | int err = -ENOMEM; | |
801 | char *tmp = kstrdup(name, GFP_KERNEL); | |
802 | ||
803 | if (tmp) { | |
804 | ovl_unescape(tmp); | |
805 | err = ovl_mount_dir_noesc(tmp, path); | |
7c03b5d4 | 806 | |
bccece1e | 807 | if (!err && path->dentry->d_flags & DCACHE_OP_REAL) { |
7925dad8 MS |
808 | pr_err("filesystem on '%s' not supported as upperdir\n", |
809 | tmp); | |
810 | path_put_init(path); | |
811 | err = -EINVAL; | |
812 | } | |
ab508822 MS |
813 | kfree(tmp); |
814 | } | |
815 | return err; | |
816 | } | |
817 | ||
6b2d5fe4 MS |
818 | static int ovl_check_namelen(struct path *path, struct ovl_fs *ofs, |
819 | const char *name) | |
ab508822 | 820 | { |
ab508822 | 821 | struct kstatfs statfs; |
6b2d5fe4 MS |
822 | int err = vfs_statfs(path, &statfs); |
823 | ||
824 | if (err) | |
1bd0a3ae | 825 | pr_err("statfs failed on '%s'\n", name); |
6b2d5fe4 MS |
826 | else |
827 | ofs->namelen = max(ofs->namelen, statfs.f_namelen); | |
828 | ||
829 | return err; | |
830 | } | |
831 | ||
832 | static int ovl_lower_dir(const char *name, struct path *path, | |
f4288844 | 833 | struct ovl_fs *ofs, int *stack_depth) |
6b2d5fe4 | 834 | { |
e487d889 | 835 | int fh_type; |
6b2d5fe4 | 836 | int err; |
ab508822 | 837 | |
a78d9f0d | 838 | err = ovl_mount_dir_noesc(name, path); |
ab508822 MS |
839 | if (err) |
840 | goto out; | |
841 | ||
6b2d5fe4 MS |
842 | err = ovl_check_namelen(path, ofs, name); |
843 | if (err) | |
ab508822 | 844 | goto out_put; |
6b2d5fe4 | 845 | |
ab508822 MS |
846 | *stack_depth = max(*stack_depth, path->mnt->mnt_sb->s_stack_depth); |
847 | ||
02bcd157 | 848 | /* |
f168f109 AG |
849 | * The inodes index feature and NFS export need to encode and decode |
850 | * file handles, so they require that all layers support them. | |
02bcd157 | 851 | */ |
e487d889 | 852 | fh_type = ovl_can_decode_fh(path->dentry->d_sb); |
f168f109 | 853 | if ((ofs->config.nfs_export || |
e487d889 | 854 | (ofs->config.index && ofs->config.upperdir)) && !fh_type) { |
02bcd157 | 855 | ofs->config.index = false; |
f168f109 | 856 | ofs->config.nfs_export = false; |
1bd0a3ae | 857 | pr_warn("fs on '%s' does not support file handles, falling back to index=off,nfs_export=off.\n", |
f168f109 | 858 | name); |
02bcd157 AG |
859 | } |
860 | ||
e487d889 AG |
861 | /* Check if lower fs has 32bit inode numbers */ |
862 | if (fh_type != FILEID_INO32_GEN) | |
0f831ec8 | 863 | ofs->xino_mode = -1; |
e487d889 | 864 | |
ab508822 MS |
865 | return 0; |
866 | ||
867 | out_put: | |
8aafcb59 | 868 | path_put_init(path); |
ab508822 MS |
869 | out: |
870 | return err; | |
871 | } | |
872 | ||
e9be9d5e MS |
873 | /* Workdir should not be subdir of upperdir and vice versa */ |
874 | static bool ovl_workdir_ok(struct dentry *workdir, struct dentry *upperdir) | |
875 | { | |
876 | bool ok = false; | |
877 | ||
878 | if (workdir != upperdir) { | |
879 | ok = (lock_rename(workdir, upperdir) == NULL); | |
880 | unlock_rename(workdir, upperdir); | |
881 | } | |
882 | return ok; | |
883 | } | |
884 | ||
a78d9f0d MS |
885 | static unsigned int ovl_split_lowerdirs(char *str) |
886 | { | |
887 | unsigned int ctr = 1; | |
888 | char *s, *d; | |
889 | ||
890 | for (s = d = str;; s++, d++) { | |
891 | if (*s == '\\') { | |
892 | s++; | |
893 | } else if (*s == ':') { | |
894 | *d = '\0'; | |
895 | ctr++; | |
896 | continue; | |
897 | } | |
898 | *d = *s; | |
899 | if (!*s) | |
900 | break; | |
901 | } | |
902 | return ctr; | |
903 | } | |
904 | ||
0eb45fc3 AG |
905 | static int __maybe_unused |
906 | ovl_posix_acl_xattr_get(const struct xattr_handler *handler, | |
907 | struct dentry *dentry, struct inode *inode, | |
908 | const char *name, void *buffer, size_t size) | |
909 | { | |
1d88f183 | 910 | return ovl_xattr_get(dentry, inode, handler->name, buffer, size); |
0eb45fc3 AG |
911 | } |
912 | ||
0c97be22 AG |
913 | static int __maybe_unused |
914 | ovl_posix_acl_xattr_set(const struct xattr_handler *handler, | |
915 | struct dentry *dentry, struct inode *inode, | |
916 | const char *name, const void *value, | |
917 | size_t size, int flags) | |
d837a49b MS |
918 | { |
919 | struct dentry *workdir = ovl_workdir(dentry); | |
09d8b586 | 920 | struct inode *realinode = ovl_inode_real(inode); |
d837a49b MS |
921 | struct posix_acl *acl = NULL; |
922 | int err; | |
923 | ||
924 | /* Check that everything is OK before copy-up */ | |
925 | if (value) { | |
926 | acl = posix_acl_from_xattr(&init_user_ns, value, size); | |
927 | if (IS_ERR(acl)) | |
928 | return PTR_ERR(acl); | |
929 | } | |
930 | err = -EOPNOTSUPP; | |
931 | if (!IS_POSIXACL(d_inode(workdir))) | |
932 | goto out_acl_release; | |
933 | if (!realinode->i_op->set_acl) | |
934 | goto out_acl_release; | |
935 | if (handler->flags == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) { | |
936 | err = acl ? -EACCES : 0; | |
937 | goto out_acl_release; | |
938 | } | |
939 | err = -EPERM; | |
940 | if (!inode_owner_or_capable(inode)) | |
941 | goto out_acl_release; | |
942 | ||
943 | posix_acl_release(acl); | |
944 | ||
fd3220d3 MS |
945 | /* |
946 | * Check if sgid bit needs to be cleared (actual setacl operation will | |
947 | * be done with mounter's capabilities and so that won't do it for us). | |
948 | */ | |
949 | if (unlikely(inode->i_mode & S_ISGID) && | |
950 | handler->flags == ACL_TYPE_ACCESS && | |
951 | !in_group_p(inode->i_gid) && | |
952 | !capable_wrt_inode_uidgid(inode, CAP_FSETID)) { | |
953 | struct iattr iattr = { .ia_valid = ATTR_KILL_SGID }; | |
954 | ||
955 | err = ovl_setattr(dentry, &iattr); | |
956 | if (err) | |
957 | return err; | |
958 | } | |
959 | ||
1d88f183 | 960 | err = ovl_xattr_set(dentry, inode, handler->name, value, size, flags); |
ce31513a | 961 | if (!err) |
09d8b586 | 962 | ovl_copyattr(ovl_inode_real(inode), inode); |
ce31513a MS |
963 | |
964 | return err; | |
d837a49b MS |
965 | |
966 | out_acl_release: | |
967 | posix_acl_release(acl); | |
968 | return err; | |
969 | } | |
970 | ||
0eb45fc3 AG |
971 | static int ovl_own_xattr_get(const struct xattr_handler *handler, |
972 | struct dentry *dentry, struct inode *inode, | |
973 | const char *name, void *buffer, size_t size) | |
974 | { | |
48fab5d7 | 975 | return -EOPNOTSUPP; |
0eb45fc3 AG |
976 | } |
977 | ||
d837a49b MS |
978 | static int ovl_own_xattr_set(const struct xattr_handler *handler, |
979 | struct dentry *dentry, struct inode *inode, | |
980 | const char *name, const void *value, | |
981 | size_t size, int flags) | |
982 | { | |
48fab5d7 | 983 | return -EOPNOTSUPP; |
d837a49b MS |
984 | } |
985 | ||
0eb45fc3 AG |
986 | static int ovl_other_xattr_get(const struct xattr_handler *handler, |
987 | struct dentry *dentry, struct inode *inode, | |
988 | const char *name, void *buffer, size_t size) | |
989 | { | |
1d88f183 | 990 | return ovl_xattr_get(dentry, inode, name, buffer, size); |
0eb45fc3 AG |
991 | } |
992 | ||
0e585ccc AG |
993 | static int ovl_other_xattr_set(const struct xattr_handler *handler, |
994 | struct dentry *dentry, struct inode *inode, | |
995 | const char *name, const void *value, | |
996 | size_t size, int flags) | |
997 | { | |
1d88f183 | 998 | return ovl_xattr_set(dentry, inode, name, value, size, flags); |
0e585ccc AG |
999 | } |
1000 | ||
0c97be22 AG |
1001 | static const struct xattr_handler __maybe_unused |
1002 | ovl_posix_acl_access_xattr_handler = { | |
d837a49b MS |
1003 | .name = XATTR_NAME_POSIX_ACL_ACCESS, |
1004 | .flags = ACL_TYPE_ACCESS, | |
0eb45fc3 | 1005 | .get = ovl_posix_acl_xattr_get, |
d837a49b MS |
1006 | .set = ovl_posix_acl_xattr_set, |
1007 | }; | |
1008 | ||
0c97be22 AG |
1009 | static const struct xattr_handler __maybe_unused |
1010 | ovl_posix_acl_default_xattr_handler = { | |
d837a49b MS |
1011 | .name = XATTR_NAME_POSIX_ACL_DEFAULT, |
1012 | .flags = ACL_TYPE_DEFAULT, | |
0eb45fc3 | 1013 | .get = ovl_posix_acl_xattr_get, |
d837a49b MS |
1014 | .set = ovl_posix_acl_xattr_set, |
1015 | }; | |
1016 | ||
1017 | static const struct xattr_handler ovl_own_xattr_handler = { | |
1018 | .prefix = OVL_XATTR_PREFIX, | |
0eb45fc3 | 1019 | .get = ovl_own_xattr_get, |
d837a49b MS |
1020 | .set = ovl_own_xattr_set, |
1021 | }; | |
1022 | ||
1023 | static const struct xattr_handler ovl_other_xattr_handler = { | |
1024 | .prefix = "", /* catch all */ | |
0eb45fc3 | 1025 | .get = ovl_other_xattr_get, |
d837a49b MS |
1026 | .set = ovl_other_xattr_set, |
1027 | }; | |
1028 | ||
1029 | static const struct xattr_handler *ovl_xattr_handlers[] = { | |
0c97be22 | 1030 | #ifdef CONFIG_FS_POSIX_ACL |
d837a49b MS |
1031 | &ovl_posix_acl_access_xattr_handler, |
1032 | &ovl_posix_acl_default_xattr_handler, | |
0c97be22 | 1033 | #endif |
d837a49b MS |
1034 | &ovl_own_xattr_handler, |
1035 | &ovl_other_xattr_handler, | |
1036 | NULL | |
1037 | }; | |
1038 | ||
146d62e5 AG |
1039 | static int ovl_setup_trap(struct super_block *sb, struct dentry *dir, |
1040 | struct inode **ptrap, const char *name) | |
1041 | { | |
1042 | struct inode *trap; | |
1043 | int err; | |
1044 | ||
1045 | trap = ovl_get_trap_inode(sb, dir); | |
1dac6f5b AB |
1046 | err = PTR_ERR_OR_ZERO(trap); |
1047 | if (err) { | |
146d62e5 | 1048 | if (err == -ELOOP) |
1bd0a3ae | 1049 | pr_err("conflicting %s path\n", name); |
146d62e5 AG |
1050 | return err; |
1051 | } | |
1052 | ||
1053 | *ptrap = trap; | |
1054 | return 0; | |
1055 | } | |
1056 | ||
0be0bfd2 AG |
1057 | /* |
1058 | * Determine how we treat concurrent use of upperdir/workdir based on the | |
1059 | * index feature. This is papering over mount leaks of container runtimes, | |
1060 | * for example, an old overlay mount is leaked and now its upperdir is | |
1061 | * attempted to be used as a lower layer in a new overlay mount. | |
1062 | */ | |
1063 | static int ovl_report_in_use(struct ovl_fs *ofs, const char *name) | |
1064 | { | |
1065 | if (ofs->config.index) { | |
1bd0a3ae | 1066 | pr_err("%s is in-use as upperdir/workdir of another mount, mount with '-o index=off' to override exclusive upperdir protection.\n", |
0be0bfd2 AG |
1067 | name); |
1068 | return -EBUSY; | |
1069 | } else { | |
1bd0a3ae | 1070 | pr_warn("%s is in-use as upperdir/workdir of another mount, accessing files from both mounts will result in undefined behavior.\n", |
0be0bfd2 AG |
1071 | name); |
1072 | return 0; | |
1073 | } | |
1074 | } | |
1075 | ||
146d62e5 AG |
1076 | static int ovl_get_upper(struct super_block *sb, struct ovl_fs *ofs, |
1077 | struct path *upperpath) | |
6ee8acf0 | 1078 | { |
5064975e | 1079 | struct vfsmount *upper_mnt; |
6ee8acf0 MS |
1080 | int err; |
1081 | ||
ad204488 | 1082 | err = ovl_mount_dir(ofs->config.upperdir, upperpath); |
6ee8acf0 MS |
1083 | if (err) |
1084 | goto out; | |
1085 | ||
1086 | /* Upper fs should not be r/o */ | |
1087 | if (sb_rdonly(upperpath->mnt->mnt_sb)) { | |
1bd0a3ae | 1088 | pr_err("upper fs is r/o, try multi-lower layers mount\n"); |
6ee8acf0 MS |
1089 | err = -EINVAL; |
1090 | goto out; | |
1091 | } | |
1092 | ||
ad204488 | 1093 | err = ovl_check_namelen(upperpath, ofs, ofs->config.upperdir); |
6ee8acf0 MS |
1094 | if (err) |
1095 | goto out; | |
1096 | ||
146d62e5 AG |
1097 | err = ovl_setup_trap(sb, upperpath->dentry, &ofs->upperdir_trap, |
1098 | "upperdir"); | |
1099 | if (err) | |
1100 | goto out; | |
1101 | ||
5064975e MS |
1102 | upper_mnt = clone_private_mount(upperpath); |
1103 | err = PTR_ERR(upper_mnt); | |
1104 | if (IS_ERR(upper_mnt)) { | |
1bd0a3ae | 1105 | pr_err("failed to clone upperpath\n"); |
5064975e MS |
1106 | goto out; |
1107 | } | |
1108 | ||
1109 | /* Don't inherit atime flags */ | |
1110 | upper_mnt->mnt_flags &= ~(MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME); | |
ad204488 | 1111 | ofs->upper_mnt = upper_mnt; |
8c25741a | 1112 | |
654255fa JX |
1113 | /* |
1114 | * Inherit SB_NOSEC flag from upperdir. | |
1115 | * | |
1116 | * This optimization changes behavior when a security related attribute | |
1117 | * (suid/sgid/security.*) is changed on an underlying layer. This is | |
1118 | * okay because we don't yet have guarantees in that case, but it will | |
1119 | * need careful treatment once we want to honour changes to underlying | |
1120 | * filesystems. | |
1121 | */ | |
1122 | if (upper_mnt->mnt_sb->s_flags & SB_NOSEC) | |
1123 | sb->s_flags |= SB_NOSEC; | |
1124 | ||
8c25741a MS |
1125 | if (ovl_inuse_trylock(ofs->upper_mnt->mnt_root)) { |
1126 | ofs->upperdir_locked = true; | |
8c25741a | 1127 | } else { |
0be0bfd2 AG |
1128 | err = ovl_report_in_use(ofs, "upperdir"); |
1129 | if (err) | |
1130 | goto out; | |
8c25741a MS |
1131 | } |
1132 | ||
6ee8acf0 MS |
1133 | err = 0; |
1134 | out: | |
1135 | return err; | |
1136 | } | |
1137 | ||
cad218ab AG |
1138 | /* |
1139 | * Returns 1 if RENAME_WHITEOUT is supported, 0 if not supported and | |
1140 | * negative values if error is encountered. | |
1141 | */ | |
1142 | static int ovl_check_rename_whiteout(struct dentry *workdir) | |
1143 | { | |
1144 | struct inode *dir = d_inode(workdir); | |
1145 | struct dentry *temp; | |
1146 | struct dentry *dest; | |
1147 | struct dentry *whiteout; | |
1148 | struct name_snapshot name; | |
1149 | int err; | |
1150 | ||
1151 | inode_lock_nested(dir, I_MUTEX_PARENT); | |
1152 | ||
1153 | temp = ovl_create_temp(workdir, OVL_CATTR(S_IFREG | 0)); | |
1154 | err = PTR_ERR(temp); | |
1155 | if (IS_ERR(temp)) | |
1156 | goto out_unlock; | |
1157 | ||
1158 | dest = ovl_lookup_temp(workdir); | |
1159 | err = PTR_ERR(dest); | |
1160 | if (IS_ERR(dest)) { | |
1161 | dput(temp); | |
1162 | goto out_unlock; | |
1163 | } | |
1164 | ||
1165 | /* Name is inline and stable - using snapshot as a copy helper */ | |
1166 | take_dentry_name_snapshot(&name, temp); | |
1167 | err = ovl_do_rename(dir, temp, dir, dest, RENAME_WHITEOUT); | |
1168 | if (err) { | |
1169 | if (err == -EINVAL) | |
1170 | err = 0; | |
1171 | goto cleanup_temp; | |
1172 | } | |
1173 | ||
1174 | whiteout = lookup_one_len(name.name.name, workdir, name.name.len); | |
1175 | err = PTR_ERR(whiteout); | |
1176 | if (IS_ERR(whiteout)) | |
1177 | goto cleanup_temp; | |
1178 | ||
1179 | err = ovl_is_whiteout(whiteout); | |
1180 | ||
1181 | /* Best effort cleanup of whiteout and temp file */ | |
1182 | if (err) | |
1183 | ovl_cleanup(dir, whiteout); | |
1184 | dput(whiteout); | |
1185 | ||
1186 | cleanup_temp: | |
1187 | ovl_cleanup(dir, temp); | |
1188 | release_dentry_name_snapshot(&name); | |
1189 | dput(temp); | |
1190 | dput(dest); | |
1191 | ||
1192 | out_unlock: | |
1193 | inode_unlock(dir); | |
1194 | ||
1195 | return err; | |
1196 | } | |
1197 | ||
146d62e5 AG |
1198 | static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs, |
1199 | struct path *workpath) | |
8ed61dc3 | 1200 | { |
2ba9d57e | 1201 | struct vfsmount *mnt = ofs->upper_mnt; |
8ed61dc3 | 1202 | struct dentry *temp; |
d80172c2 AG |
1203 | bool rename_whiteout; |
1204 | bool d_type; | |
e487d889 | 1205 | int fh_type; |
8ed61dc3 MS |
1206 | int err; |
1207 | ||
2ba9d57e AG |
1208 | err = mnt_want_write(mnt); |
1209 | if (err) | |
1210 | return err; | |
1211 | ||
ad204488 MS |
1212 | ofs->workdir = ovl_workdir_create(ofs, OVL_WORKDIR_NAME, false); |
1213 | if (!ofs->workdir) | |
2ba9d57e | 1214 | goto out; |
8ed61dc3 | 1215 | |
146d62e5 AG |
1216 | err = ovl_setup_trap(sb, ofs->workdir, &ofs->workdir_trap, "workdir"); |
1217 | if (err) | |
1218 | goto out; | |
1219 | ||
8ed61dc3 MS |
1220 | /* |
1221 | * Upper should support d_type, else whiteouts are visible. Given | |
1222 | * workdir and upper are on same fs, we can do iterate_dir() on | |
1223 | * workdir. This check requires successful creation of workdir in | |
1224 | * previous step. | |
1225 | */ | |
1226 | err = ovl_check_d_type_supported(workpath); | |
1227 | if (err < 0) | |
2ba9d57e | 1228 | goto out; |
8ed61dc3 | 1229 | |
d80172c2 AG |
1230 | d_type = err; |
1231 | if (!d_type) | |
1bd0a3ae | 1232 | pr_warn("upper fs needs to support d_type.\n"); |
8ed61dc3 MS |
1233 | |
1234 | /* Check if upper/work fs supports O_TMPFILE */ | |
ad204488 MS |
1235 | temp = ovl_do_tmpfile(ofs->workdir, S_IFREG | 0); |
1236 | ofs->tmpfile = !IS_ERR(temp); | |
1237 | if (ofs->tmpfile) | |
8ed61dc3 MS |
1238 | dput(temp); |
1239 | else | |
1bd0a3ae | 1240 | pr_warn("upper fs does not support tmpfile.\n"); |
8ed61dc3 | 1241 | |
cad218ab AG |
1242 | |
1243 | /* Check if upper/work fs supports RENAME_WHITEOUT */ | |
1244 | err = ovl_check_rename_whiteout(ofs->workdir); | |
1245 | if (err < 0) | |
1246 | goto out; | |
1247 | ||
d80172c2 AG |
1248 | rename_whiteout = err; |
1249 | if (!rename_whiteout) | |
cad218ab AG |
1250 | pr_warn("upper fs does not support RENAME_WHITEOUT.\n"); |
1251 | ||
8ed61dc3 MS |
1252 | /* |
1253 | * Check if upper/work fs supports trusted.overlay.* xattr | |
1254 | */ | |
ad204488 | 1255 | err = ovl_do_setxattr(ofs->workdir, OVL_XATTR_OPAQUE, "0", 1, 0); |
8ed61dc3 | 1256 | if (err) { |
ad204488 | 1257 | ofs->noxattr = true; |
a683737b | 1258 | ofs->config.index = false; |
d5791044 | 1259 | ofs->config.metacopy = false; |
1bd0a3ae | 1260 | pr_warn("upper fs does not support xattr, falling back to index=off and metacopy=off.\n"); |
2ba9d57e | 1261 | err = 0; |
8ed61dc3 | 1262 | } else { |
ad204488 | 1263 | vfs_removexattr(ofs->workdir, OVL_XATTR_OPAQUE); |
8ed61dc3 MS |
1264 | } |
1265 | ||
d80172c2 AG |
1266 | /* |
1267 | * We allowed sub-optimal upper fs configuration and don't want to break | |
1268 | * users over kernel upgrade, but we never allowed remote upper fs, so | |
1269 | * we can enforce strict requirements for remote upper fs. | |
1270 | */ | |
1271 | if (ovl_dentry_remote(ofs->workdir) && | |
1272 | (!d_type || !rename_whiteout || ofs->noxattr)) { | |
1273 | pr_err("upper fs missing required features.\n"); | |
1274 | err = -EINVAL; | |
1275 | goto out; | |
1276 | } | |
1277 | ||
8ed61dc3 | 1278 | /* Check if upper/work fs supports file handles */ |
e487d889 AG |
1279 | fh_type = ovl_can_decode_fh(ofs->workdir->d_sb); |
1280 | if (ofs->config.index && !fh_type) { | |
ad204488 | 1281 | ofs->config.index = false; |
1bd0a3ae | 1282 | pr_warn("upper fs does not support file handles, falling back to index=off.\n"); |
8ed61dc3 MS |
1283 | } |
1284 | ||
e487d889 AG |
1285 | /* Check if upper fs has 32bit inode numbers */ |
1286 | if (fh_type != FILEID_INO32_GEN) | |
0f831ec8 | 1287 | ofs->xino_mode = -1; |
e487d889 | 1288 | |
f168f109 AG |
1289 | /* NFS export of r/w mount depends on index */ |
1290 | if (ofs->config.nfs_export && !ofs->config.index) { | |
1bd0a3ae | 1291 | pr_warn("NFS export requires \"index=on\", falling back to nfs_export=off.\n"); |
f168f109 AG |
1292 | ofs->config.nfs_export = false; |
1293 | } | |
2ba9d57e AG |
1294 | out: |
1295 | mnt_drop_write(mnt); | |
1296 | return err; | |
8ed61dc3 MS |
1297 | } |
1298 | ||
146d62e5 AG |
1299 | static int ovl_get_workdir(struct super_block *sb, struct ovl_fs *ofs, |
1300 | struct path *upperpath) | |
520d7c86 MS |
1301 | { |
1302 | int err; | |
bca44b52 | 1303 | struct path workpath = { }; |
520d7c86 | 1304 | |
ad204488 | 1305 | err = ovl_mount_dir(ofs->config.workdir, &workpath); |
520d7c86 MS |
1306 | if (err) |
1307 | goto out; | |
1308 | ||
1309 | err = -EINVAL; | |
bca44b52 | 1310 | if (upperpath->mnt != workpath.mnt) { |
1bd0a3ae | 1311 | pr_err("workdir and upperdir must reside under the same mount\n"); |
520d7c86 MS |
1312 | goto out; |
1313 | } | |
bca44b52 | 1314 | if (!ovl_workdir_ok(workpath.dentry, upperpath->dentry)) { |
1bd0a3ae | 1315 | pr_err("workdir and upperdir must be separate subtrees\n"); |
520d7c86 MS |
1316 | goto out; |
1317 | } | |
1318 | ||
8c25741a MS |
1319 | ofs->workbasedir = dget(workpath.dentry); |
1320 | ||
8c25741a | 1321 | if (ovl_inuse_trylock(ofs->workbasedir)) { |
ad204488 | 1322 | ofs->workdir_locked = true; |
520d7c86 | 1323 | } else { |
0be0bfd2 AG |
1324 | err = ovl_report_in_use(ofs, "workdir"); |
1325 | if (err) | |
1326 | goto out; | |
520d7c86 MS |
1327 | } |
1328 | ||
0be0bfd2 AG |
1329 | err = ovl_setup_trap(sb, ofs->workbasedir, &ofs->workbasedir_trap, |
1330 | "workdir"); | |
1331 | if (err) | |
1332 | goto out; | |
1333 | ||
146d62e5 | 1334 | err = ovl_make_workdir(sb, ofs, &workpath); |
bca44b52 | 1335 | |
520d7c86 | 1336 | out: |
bca44b52 MS |
1337 | path_put(&workpath); |
1338 | ||
520d7c86 MS |
1339 | return err; |
1340 | } | |
1341 | ||
146d62e5 AG |
1342 | static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs, |
1343 | struct ovl_entry *oe, struct path *upperpath) | |
f7e3a7d9 | 1344 | { |
2ba9d57e | 1345 | struct vfsmount *mnt = ofs->upper_mnt; |
f7e3a7d9 MS |
1346 | int err; |
1347 | ||
2ba9d57e AG |
1348 | err = mnt_want_write(mnt); |
1349 | if (err) | |
1350 | return err; | |
1351 | ||
f7e3a7d9 | 1352 | /* Verify lower root is upper root origin */ |
d9768076 | 1353 | err = ovl_verify_origin(upperpath->dentry, oe->lowerstack[0].dentry, |
05122443 | 1354 | true); |
f7e3a7d9 | 1355 | if (err) { |
1bd0a3ae | 1356 | pr_err("failed to verify upper root origin\n"); |
f7e3a7d9 MS |
1357 | goto out; |
1358 | } | |
1359 | ||
ad204488 MS |
1360 | ofs->indexdir = ovl_workdir_create(ofs, OVL_INDEXDIR_NAME, true); |
1361 | if (ofs->indexdir) { | |
146d62e5 AG |
1362 | err = ovl_setup_trap(sb, ofs->indexdir, &ofs->indexdir_trap, |
1363 | "indexdir"); | |
1364 | if (err) | |
1365 | goto out; | |
1366 | ||
ad1d615c AG |
1367 | /* |
1368 | * Verify upper root is exclusively associated with index dir. | |
1369 | * Older kernels stored upper fh in "trusted.overlay.origin" | |
1370 | * xattr. If that xattr exists, verify that it is a match to | |
1371 | * upper dir file handle. In any case, verify or set xattr | |
1372 | * "trusted.overlay.upper" to indicate that index may have | |
1373 | * directory entries. | |
1374 | */ | |
1375 | if (ovl_check_origin_xattr(ofs->indexdir)) { | |
1376 | err = ovl_verify_set_fh(ofs->indexdir, OVL_XATTR_ORIGIN, | |
1377 | upperpath->dentry, true, false); | |
1378 | if (err) | |
1bd0a3ae | 1379 | pr_err("failed to verify index dir 'origin' xattr\n"); |
ad1d615c AG |
1380 | } |
1381 | err = ovl_verify_upper(ofs->indexdir, upperpath->dentry, true); | |
f7e3a7d9 | 1382 | if (err) |
1bd0a3ae | 1383 | pr_err("failed to verify index dir 'upper' xattr\n"); |
f7e3a7d9 MS |
1384 | |
1385 | /* Cleanup bad/stale/orphan index entries */ | |
1386 | if (!err) | |
1eff1a1d | 1387 | err = ovl_indexdir_cleanup(ofs); |
f7e3a7d9 | 1388 | } |
ad204488 | 1389 | if (err || !ofs->indexdir) |
1bd0a3ae | 1390 | pr_warn("try deleting index dir or mounting with '-o index=off' to disable inodes index.\n"); |
f7e3a7d9 MS |
1391 | |
1392 | out: | |
2ba9d57e | 1393 | mnt_drop_write(mnt); |
f7e3a7d9 MS |
1394 | return err; |
1395 | } | |
1396 | ||
9df085f3 AG |
1397 | static bool ovl_lower_uuid_ok(struct ovl_fs *ofs, const uuid_t *uuid) |
1398 | { | |
1399 | unsigned int i; | |
1400 | ||
7e63c87f | 1401 | if (!ofs->config.nfs_export && !ofs->upper_mnt) |
9df085f3 AG |
1402 | return true; |
1403 | ||
1b81dddd | 1404 | for (i = 0; i < ofs->numfs; i++) { |
9df085f3 AG |
1405 | /* |
1406 | * We use uuid to associate an overlay lower file handle with a | |
1407 | * lower layer, so we can accept lower fs with null uuid as long | |
1408 | * as all lower layers with null uuid are on the same fs. | |
7e63c87f AG |
1409 | * if we detect multiple lower fs with the same uuid, we |
1410 | * disable lower file handle decoding on all of them. | |
9df085f3 | 1411 | */ |
1b81dddd AG |
1412 | if (ofs->fs[i].is_lower && |
1413 | uuid_equal(&ofs->fs[i].sb->s_uuid, uuid)) { | |
07f1e596 | 1414 | ofs->fs[i].bad_uuid = true; |
9df085f3 | 1415 | return false; |
7e63c87f | 1416 | } |
9df085f3 AG |
1417 | } |
1418 | return true; | |
1419 | } | |
1420 | ||
5148626b | 1421 | /* Get a unique fsid for the layer */ |
9df085f3 | 1422 | static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path) |
5148626b | 1423 | { |
9df085f3 | 1424 | struct super_block *sb = path->mnt->mnt_sb; |
5148626b AG |
1425 | unsigned int i; |
1426 | dev_t dev; | |
1427 | int err; | |
7e63c87f | 1428 | bool bad_uuid = false; |
5148626b | 1429 | |
07f1e596 AG |
1430 | for (i = 0; i < ofs->numfs; i++) { |
1431 | if (ofs->fs[i].sb == sb) | |
1432 | return i; | |
5148626b AG |
1433 | } |
1434 | ||
9df085f3 | 1435 | if (!ovl_lower_uuid_ok(ofs, &sb->s_uuid)) { |
7e63c87f AG |
1436 | bad_uuid = true; |
1437 | if (ofs->config.index || ofs->config.nfs_export) { | |
1438 | ofs->config.index = false; | |
1439 | ofs->config.nfs_export = false; | |
1bd0a3ae | 1440 | pr_warn("%s uuid detected in lower fs '%pd2', falling back to index=off,nfs_export=off.\n", |
7e63c87f AG |
1441 | uuid_is_null(&sb->s_uuid) ? "null" : |
1442 | "conflicting", | |
1443 | path->dentry); | |
1444 | } | |
9df085f3 AG |
1445 | } |
1446 | ||
5148626b AG |
1447 | err = get_anon_bdev(&dev); |
1448 | if (err) { | |
1bd0a3ae | 1449 | pr_err("failed to get anonymous bdev for lowerpath\n"); |
5148626b AG |
1450 | return err; |
1451 | } | |
1452 | ||
07f1e596 AG |
1453 | ofs->fs[ofs->numfs].sb = sb; |
1454 | ofs->fs[ofs->numfs].pseudo_dev = dev; | |
1455 | ofs->fs[ofs->numfs].bad_uuid = bad_uuid; | |
5148626b | 1456 | |
07f1e596 | 1457 | return ofs->numfs++; |
5148626b AG |
1458 | } |
1459 | ||
94375f9d AG |
1460 | static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs, |
1461 | struct path *stack, unsigned int numlower) | |
520d7c86 MS |
1462 | { |
1463 | int err; | |
1464 | unsigned int i; | |
13464165 | 1465 | struct ovl_layer *layers; |
520d7c86 MS |
1466 | |
1467 | err = -ENOMEM; | |
13464165 MS |
1468 | layers = kcalloc(numlower + 1, sizeof(struct ovl_layer), GFP_KERNEL); |
1469 | if (!layers) | |
520d7c86 | 1470 | goto out; |
13464165 | 1471 | ofs->layers = layers; |
5148626b | 1472 | |
07f1e596 AG |
1473 | ofs->fs = kcalloc(numlower + 1, sizeof(struct ovl_sb), GFP_KERNEL); |
1474 | if (ofs->fs == NULL) | |
5148626b AG |
1475 | goto out; |
1476 | ||
07f1e596 AG |
1477 | /* idx/fsid 0 are reserved for upper fs even with lower only overlay */ |
1478 | ofs->numfs++; | |
1479 | ||
13464165 MS |
1480 | layers[0].mnt = ofs->upper_mnt; |
1481 | layers[0].idx = 0; | |
1482 | layers[0].fsid = 0; | |
94375f9d AG |
1483 | ofs->numlayer = 1; |
1484 | ||
07f1e596 | 1485 | /* |
b7bf9908 AG |
1486 | * All lower layers that share the same fs as upper layer, use the same |
1487 | * pseudo_dev as upper layer. Allocate fs[0].pseudo_dev even for lower | |
1488 | * only overlay to simplify ovl_fs_free(). | |
1b81dddd | 1489 | * is_lower will be set if upper fs is shared with a lower layer. |
07f1e596 | 1490 | */ |
b7bf9908 AG |
1491 | err = get_anon_bdev(&ofs->fs[0].pseudo_dev); |
1492 | if (err) { | |
1493 | pr_err("failed to get anonymous bdev for upper fs\n"); | |
1494 | goto out; | |
1495 | } | |
1496 | ||
07f1e596 AG |
1497 | if (ofs->upper_mnt) { |
1498 | ofs->fs[0].sb = ofs->upper_mnt->mnt_sb; | |
1b81dddd | 1499 | ofs->fs[0].is_lower = false; |
07f1e596 AG |
1500 | } |
1501 | ||
520d7c86 MS |
1502 | for (i = 0; i < numlower; i++) { |
1503 | struct vfsmount *mnt; | |
146d62e5 | 1504 | struct inode *trap; |
5148626b | 1505 | int fsid; |
520d7c86 | 1506 | |
9df085f3 | 1507 | err = fsid = ovl_get_fsid(ofs, &stack[i]); |
5148626b | 1508 | if (err < 0) |
520d7c86 | 1509 | goto out; |
520d7c86 | 1510 | |
146d62e5 AG |
1511 | err = ovl_setup_trap(sb, stack[i].dentry, &trap, "lowerdir"); |
1512 | if (err) | |
1513 | goto out; | |
1514 | ||
0be0bfd2 AG |
1515 | if (ovl_is_inuse(stack[i].dentry)) { |
1516 | err = ovl_report_in_use(ofs, "lowerdir"); | |
1517 | if (err) | |
1518 | goto out; | |
1519 | } | |
1520 | ||
520d7c86 MS |
1521 | mnt = clone_private_mount(&stack[i]); |
1522 | err = PTR_ERR(mnt); | |
1523 | if (IS_ERR(mnt)) { | |
1bd0a3ae | 1524 | pr_err("failed to clone lowerpath\n"); |
146d62e5 | 1525 | iput(trap); |
520d7c86 MS |
1526 | goto out; |
1527 | } | |
5148626b | 1528 | |
520d7c86 MS |
1529 | /* |
1530 | * Make lower layers R/O. That way fchmod/fchown on lower file | |
1531 | * will fail instead of modifying lower fs. | |
1532 | */ | |
1533 | mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME; | |
1534 | ||
13464165 MS |
1535 | layers[ofs->numlayer].trap = trap; |
1536 | layers[ofs->numlayer].mnt = mnt; | |
1537 | layers[ofs->numlayer].idx = ofs->numlayer; | |
1538 | layers[ofs->numlayer].fsid = fsid; | |
1539 | layers[ofs->numlayer].fs = &ofs->fs[fsid]; | |
94375f9d | 1540 | ofs->numlayer++; |
1b81dddd | 1541 | ofs->fs[fsid].is_lower = true; |
520d7c86 | 1542 | } |
e487d889 | 1543 | |
795939a9 AG |
1544 | /* |
1545 | * When all layers on same fs, overlay can use real inode numbers. | |
926e94d7 AG |
1546 | * With mount option "xino=<on|auto>", mounter declares that there are |
1547 | * enough free high bits in underlying fs to hold the unique fsid. | |
795939a9 AG |
1548 | * If overlayfs does encounter underlying inodes using the high xino |
1549 | * bits reserved for fsid, it emits a warning and uses the original | |
dfe51d47 AG |
1550 | * inode number or a non persistent inode number allocated from a |
1551 | * dedicated range. | |
795939a9 | 1552 | */ |
07f1e596 | 1553 | if (ofs->numfs - !ofs->upper_mnt == 1) { |
0f831ec8 AG |
1554 | if (ofs->config.xino == OVL_XINO_ON) |
1555 | pr_info("\"xino=on\" is useless with all layers on same fs, ignore.\n"); | |
1556 | ofs->xino_mode = 0; | |
53afcd31 AG |
1557 | } else if (ofs->config.xino == OVL_XINO_OFF) { |
1558 | ofs->xino_mode = -1; | |
926e94d7 | 1559 | } else if (ofs->xino_mode < 0) { |
795939a9 | 1560 | /* |
07f1e596 | 1561 | * This is a roundup of number of bits needed for encoding |
dfe51d47 AG |
1562 | * fsid, where fsid 0 is reserved for upper fs (even with |
1563 | * lower only overlay) +1 extra bit is reserved for the non | |
1564 | * persistent inode number range that is used for resolving | |
1565 | * xino lower bits overflow. | |
795939a9 | 1566 | */ |
dfe51d47 AG |
1567 | BUILD_BUG_ON(ilog2(OVL_MAX_STACK) > 30); |
1568 | ofs->xino_mode = ilog2(ofs->numfs - 1) + 2; | |
795939a9 AG |
1569 | } |
1570 | ||
0f831ec8 | 1571 | if (ofs->xino_mode > 0) { |
1bd0a3ae | 1572 | pr_info("\"xino\" feature enabled using %d upper inode bits.\n", |
0f831ec8 | 1573 | ofs->xino_mode); |
795939a9 | 1574 | } |
e487d889 | 1575 | |
520d7c86 MS |
1576 | err = 0; |
1577 | out: | |
1578 | return err; | |
1579 | } | |
1580 | ||
4155c10a | 1581 | static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, |
ad204488 | 1582 | struct ovl_fs *ofs) |
53dbb0b4 MS |
1583 | { |
1584 | int err; | |
1585 | char *lowertmp, *lower; | |
4155c10a MS |
1586 | struct path *stack = NULL; |
1587 | unsigned int stacklen, numlower = 0, i; | |
4155c10a | 1588 | struct ovl_entry *oe; |
53dbb0b4 MS |
1589 | |
1590 | err = -ENOMEM; | |
ad204488 | 1591 | lowertmp = kstrdup(ofs->config.lowerdir, GFP_KERNEL); |
53dbb0b4 | 1592 | if (!lowertmp) |
4155c10a | 1593 | goto out_err; |
53dbb0b4 MS |
1594 | |
1595 | err = -EINVAL; | |
1596 | stacklen = ovl_split_lowerdirs(lowertmp); | |
1597 | if (stacklen > OVL_MAX_STACK) { | |
1bd0a3ae | 1598 | pr_err("too many lower directories, limit is %d\n", |
53dbb0b4 | 1599 | OVL_MAX_STACK); |
4155c10a | 1600 | goto out_err; |
ad204488 | 1601 | } else if (!ofs->config.upperdir && stacklen == 1) { |
1bd0a3ae | 1602 | pr_err("at least 2 lowerdir are needed while upperdir nonexistent\n"); |
4155c10a | 1603 | goto out_err; |
f168f109 AG |
1604 | } else if (!ofs->config.upperdir && ofs->config.nfs_export && |
1605 | ofs->config.redirect_follow) { | |
1bd0a3ae | 1606 | pr_warn("NFS export requires \"redirect_dir=nofollow\" on non-upper mount, falling back to nfs_export=off.\n"); |
f168f109 | 1607 | ofs->config.nfs_export = false; |
53dbb0b4 MS |
1608 | } |
1609 | ||
1610 | err = -ENOMEM; | |
1611 | stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL); | |
1612 | if (!stack) | |
4155c10a | 1613 | goto out_err; |
53dbb0b4 MS |
1614 | |
1615 | err = -EINVAL; | |
1616 | lower = lowertmp; | |
1617 | for (numlower = 0; numlower < stacklen; numlower++) { | |
ad204488 | 1618 | err = ovl_lower_dir(lower, &stack[numlower], ofs, |
f4288844 | 1619 | &sb->s_stack_depth); |
53dbb0b4 | 1620 | if (err) |
4155c10a | 1621 | goto out_err; |
53dbb0b4 MS |
1622 | |
1623 | lower = strchr(lower, '\0') + 1; | |
1624 | } | |
1625 | ||
1626 | err = -EINVAL; | |
1627 | sb->s_stack_depth++; | |
1628 | if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { | |
1bd0a3ae | 1629 | pr_err("maximum fs stacking depth exceeded\n"); |
4155c10a | 1630 | goto out_err; |
53dbb0b4 MS |
1631 | } |
1632 | ||
94375f9d | 1633 | err = ovl_get_layers(sb, ofs, stack, numlower); |
4155c10a MS |
1634 | if (err) |
1635 | goto out_err; | |
1636 | ||
1637 | err = -ENOMEM; | |
1638 | oe = ovl_alloc_entry(numlower); | |
1639 | if (!oe) | |
1640 | goto out_err; | |
1641 | ||
1642 | for (i = 0; i < numlower; i++) { | |
1643 | oe->lowerstack[i].dentry = dget(stack[i].dentry); | |
94375f9d | 1644 | oe->lowerstack[i].layer = &ofs->layers[i+1]; |
4155c10a | 1645 | } |
53dbb0b4 | 1646 | |
53dbb0b4 | 1647 | out: |
53dbb0b4 MS |
1648 | for (i = 0; i < numlower; i++) |
1649 | path_put(&stack[i]); | |
1650 | kfree(stack); | |
4155c10a MS |
1651 | kfree(lowertmp); |
1652 | ||
1653 | return oe; | |
1654 | ||
1655 | out_err: | |
1656 | oe = ERR_PTR(err); | |
53dbb0b4 MS |
1657 | goto out; |
1658 | } | |
1659 | ||
146d62e5 AG |
1660 | /* |
1661 | * Check if this layer root is a descendant of: | |
1662 | * - another layer of this overlayfs instance | |
1663 | * - upper/work dir of any overlayfs instance | |
146d62e5 | 1664 | */ |
0be0bfd2 AG |
1665 | static int ovl_check_layer(struct super_block *sb, struct ovl_fs *ofs, |
1666 | struct dentry *dentry, const char *name) | |
146d62e5 | 1667 | { |
9179c21d | 1668 | struct dentry *next = dentry, *parent; |
146d62e5 AG |
1669 | int err = 0; |
1670 | ||
9179c21d | 1671 | if (!dentry) |
146d62e5 AG |
1672 | return 0; |
1673 | ||
9179c21d MS |
1674 | parent = dget_parent(next); |
1675 | ||
1676 | /* Walk back ancestors to root (inclusive) looking for traps */ | |
1677 | while (!err && parent != next) { | |
0be0bfd2 | 1678 | if (ovl_lookup_trap_inode(sb, parent)) { |
146d62e5 | 1679 | err = -ELOOP; |
1bd0a3ae | 1680 | pr_err("overlapping %s path\n", name); |
0be0bfd2 AG |
1681 | } else if (ovl_is_inuse(parent)) { |
1682 | err = ovl_report_in_use(ofs, name); | |
146d62e5 | 1683 | } |
146d62e5 | 1684 | next = parent; |
9179c21d MS |
1685 | parent = dget_parent(next); |
1686 | dput(next); | |
146d62e5 AG |
1687 | } |
1688 | ||
9179c21d | 1689 | dput(parent); |
146d62e5 AG |
1690 | |
1691 | return err; | |
1692 | } | |
1693 | ||
1694 | /* | |
1695 | * Check if any of the layers or work dirs overlap. | |
1696 | */ | |
1697 | static int ovl_check_overlapping_layers(struct super_block *sb, | |
1698 | struct ovl_fs *ofs) | |
1699 | { | |
1700 | int i, err; | |
1701 | ||
1702 | if (ofs->upper_mnt) { | |
0be0bfd2 AG |
1703 | err = ovl_check_layer(sb, ofs, ofs->upper_mnt->mnt_root, |
1704 | "upperdir"); | |
146d62e5 AG |
1705 | if (err) |
1706 | return err; | |
1707 | ||
1708 | /* | |
1709 | * Checking workbasedir avoids hitting ovl_is_inuse(parent) of | |
1710 | * this instance and covers overlapping work and index dirs, | |
1711 | * unless work or index dir have been moved since created inside | |
1712 | * workbasedir. In that case, we already have their traps in | |
1713 | * inode cache and we will catch that case on lookup. | |
1714 | */ | |
0be0bfd2 | 1715 | err = ovl_check_layer(sb, ofs, ofs->workbasedir, "workdir"); |
146d62e5 AG |
1716 | if (err) |
1717 | return err; | |
1718 | } | |
1719 | ||
94375f9d | 1720 | for (i = 1; i < ofs->numlayer; i++) { |
0be0bfd2 | 1721 | err = ovl_check_layer(sb, ofs, |
94375f9d | 1722 | ofs->layers[i].mnt->mnt_root, |
146d62e5 AG |
1723 | "lowerdir"); |
1724 | if (err) | |
1725 | return err; | |
1726 | } | |
1727 | ||
1728 | return 0; | |
1729 | } | |
1730 | ||
2effc5c2 AG |
1731 | static struct dentry *ovl_get_root(struct super_block *sb, |
1732 | struct dentry *upperdentry, | |
1733 | struct ovl_entry *oe) | |
1734 | { | |
1735 | struct dentry *root; | |
62c832ed AG |
1736 | struct ovl_path *lowerpath = &oe->lowerstack[0]; |
1737 | unsigned long ino = d_inode(lowerpath->dentry)->i_ino; | |
1738 | int fsid = lowerpath->layer->fsid; | |
1739 | struct ovl_inode_params oip = { | |
1740 | .upperdentry = upperdentry, | |
1741 | .lowerpath = lowerpath, | |
1742 | }; | |
2effc5c2 AG |
1743 | |
1744 | root = d_make_root(ovl_new_inode(sb, S_IFDIR, 0)); | |
1745 | if (!root) | |
1746 | return NULL; | |
1747 | ||
1748 | root->d_fsdata = oe; | |
1749 | ||
1750 | if (upperdentry) { | |
62c832ed AG |
1751 | /* Root inode uses upper st_ino/i_ino */ |
1752 | ino = d_inode(upperdentry)->i_ino; | |
1753 | fsid = 0; | |
2effc5c2 AG |
1754 | ovl_dentry_set_upper_alias(root); |
1755 | if (ovl_is_impuredir(upperdentry)) | |
1756 | ovl_set_flag(OVL_IMPURE, d_inode(root)); | |
1757 | } | |
1758 | ||
1759 | /* Root is always merge -> can have whiteouts */ | |
1760 | ovl_set_flag(OVL_WHITEOUTS, d_inode(root)); | |
1761 | ovl_dentry_set_flag(OVL_E_CONNECTED, root); | |
1762 | ovl_set_upperdata(d_inode(root)); | |
62c832ed | 1763 | ovl_inode_init(d_inode(root), &oip, ino, fsid); |
f4288844 | 1764 | ovl_dentry_update_reval(root, upperdentry, DCACHE_OP_WEAK_REVALIDATE); |
2effc5c2 AG |
1765 | |
1766 | return root; | |
1767 | } | |
1768 | ||
e9be9d5e MS |
1769 | static int ovl_fill_super(struct super_block *sb, void *data, int silent) |
1770 | { | |
33006cdf | 1771 | struct path upperpath = { }; |
e9be9d5e | 1772 | struct dentry *root_dentry; |
4155c10a | 1773 | struct ovl_entry *oe; |
ad204488 | 1774 | struct ovl_fs *ofs; |
51f8f3c4 | 1775 | struct cred *cred; |
e9be9d5e MS |
1776 | int err; |
1777 | ||
f4288844 MS |
1778 | sb->s_d_op = &ovl_dentry_operations; |
1779 | ||
f45827e8 | 1780 | err = -ENOMEM; |
ad204488 MS |
1781 | ofs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL); |
1782 | if (!ofs) | |
e9be9d5e MS |
1783 | goto out; |
1784 | ||
ad204488 | 1785 | ofs->creator_cred = cred = prepare_creds(); |
c6fe6254 MS |
1786 | if (!cred) |
1787 | goto out_err; | |
1788 | ||
c21c839b CX |
1789 | /* Is there a reason anyone would want not to share whiteouts? */ |
1790 | ofs->share_whiteout = true; | |
1791 | ||
ad204488 | 1792 | ofs->config.index = ovl_index_def; |
f168f109 | 1793 | ofs->config.nfs_export = ovl_nfs_export_def; |
795939a9 | 1794 | ofs->config.xino = ovl_xino_def(); |
d5791044 | 1795 | ofs->config.metacopy = ovl_metacopy_def; |
ad204488 | 1796 | err = ovl_parse_opt((char *) data, &ofs->config); |
f45827e8 | 1797 | if (err) |
a9075cdb | 1798 | goto out_err; |
f45827e8 | 1799 | |
e9be9d5e | 1800 | err = -EINVAL; |
ad204488 | 1801 | if (!ofs->config.lowerdir) { |
07f2af7b | 1802 | if (!silent) |
1bd0a3ae | 1803 | pr_err("missing 'lowerdir'\n"); |
a9075cdb | 1804 | goto out_err; |
e9be9d5e MS |
1805 | } |
1806 | ||
53a08cb9 | 1807 | sb->s_stack_depth = 0; |
cf9a6784 | 1808 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
4d314f78 | 1809 | atomic_long_set(&ofs->last_ino, 1); |
e487d889 | 1810 | /* Assume underlaying fs uses 32bit inodes unless proven otherwise */ |
53afcd31 | 1811 | if (ofs->config.xino != OVL_XINO_OFF) { |
0f831ec8 | 1812 | ofs->xino_mode = BITS_PER_LONG - 32; |
53afcd31 AG |
1813 | if (!ofs->xino_mode) { |
1814 | pr_warn("xino not supported on 32bit kernel, falling back to xino=off.\n"); | |
1815 | ofs->config.xino = OVL_XINO_OFF; | |
1816 | } | |
1817 | } | |
795939a9 | 1818 | |
146d62e5 AG |
1819 | /* alloc/destroy_inode needed for setting up traps in inode cache */ |
1820 | sb->s_op = &ovl_super_operations; | |
1821 | ||
ad204488 MS |
1822 | if (ofs->config.upperdir) { |
1823 | if (!ofs->config.workdir) { | |
1bd0a3ae | 1824 | pr_err("missing 'workdir'\n"); |
a9075cdb | 1825 | goto out_err; |
53a08cb9 | 1826 | } |
e9be9d5e | 1827 | |
146d62e5 | 1828 | err = ovl_get_upper(sb, ofs, &upperpath); |
53a08cb9 | 1829 | if (err) |
a9075cdb | 1830 | goto out_err; |
2cac0c00 | 1831 | |
146d62e5 | 1832 | err = ovl_get_workdir(sb, ofs, &upperpath); |
8ed61dc3 | 1833 | if (err) |
a9075cdb | 1834 | goto out_err; |
c6fe6254 | 1835 | |
ad204488 | 1836 | if (!ofs->workdir) |
1751e8a6 | 1837 | sb->s_flags |= SB_RDONLY; |
6e88256e | 1838 | |
ad204488 MS |
1839 | sb->s_stack_depth = ofs->upper_mnt->mnt_sb->s_stack_depth; |
1840 | sb->s_time_gran = ofs->upper_mnt->mnt_sb->s_time_gran; | |
c6fe6254 | 1841 | |
e9be9d5e | 1842 | } |
ad204488 | 1843 | oe = ovl_get_lowerstack(sb, ofs); |
4155c10a MS |
1844 | err = PTR_ERR(oe); |
1845 | if (IS_ERR(oe)) | |
a9075cdb | 1846 | goto out_err; |
e9be9d5e | 1847 | |
71cbad7e | 1848 | /* If the upper fs is nonexistent, we mark overlayfs r/o too */ |
ad204488 | 1849 | if (!ofs->upper_mnt) |
1751e8a6 | 1850 | sb->s_flags |= SB_RDONLY; |
e9be9d5e | 1851 | |
ad204488 | 1852 | if (!(ovl_force_readonly(ofs)) && ofs->config.index) { |
62a8a85b AG |
1853 | /* index dir will act also as workdir */ |
1854 | dput(ofs->workdir); | |
1855 | ofs->workdir = NULL; | |
1856 | iput(ofs->workdir_trap); | |
1857 | ofs->workdir_trap = NULL; | |
1858 | ||
146d62e5 | 1859 | err = ovl_get_indexdir(sb, ofs, oe, &upperpath); |
54fb347e | 1860 | if (err) |
4155c10a | 1861 | goto out_free_oe; |
6e88256e | 1862 | |
972d0093 | 1863 | /* Force r/o mount with no index dir */ |
62a8a85b AG |
1864 | if (ofs->indexdir) |
1865 | ofs->workdir = dget(ofs->indexdir); | |
1866 | else | |
1751e8a6 | 1867 | sb->s_flags |= SB_RDONLY; |
02bcd157 AG |
1868 | } |
1869 | ||
146d62e5 AG |
1870 | err = ovl_check_overlapping_layers(sb, ofs); |
1871 | if (err) | |
1872 | goto out_free_oe; | |
1873 | ||
972d0093 | 1874 | /* Show index=off in /proc/mounts for forced r/o mount */ |
f168f109 | 1875 | if (!ofs->indexdir) { |
ad204488 | 1876 | ofs->config.index = false; |
f168f109 | 1877 | if (ofs->upper_mnt && ofs->config.nfs_export) { |
1bd0a3ae | 1878 | pr_warn("NFS export requires an index dir, falling back to nfs_export=off.\n"); |
f168f109 AG |
1879 | ofs->config.nfs_export = false; |
1880 | } | |
1881 | } | |
02bcd157 | 1882 | |
d5791044 | 1883 | if (ofs->config.metacopy && ofs->config.nfs_export) { |
1bd0a3ae | 1884 | pr_warn("NFS export is not supported with metadata only copy up, falling back to nfs_export=off.\n"); |
d5791044 VG |
1885 | ofs->config.nfs_export = false; |
1886 | } | |
1887 | ||
8383f174 AG |
1888 | if (ofs->config.nfs_export) |
1889 | sb->s_export_op = &ovl_export_operations; | |
1890 | ||
51f8f3c4 KK |
1891 | /* Never override disk quota limits or use reserved space */ |
1892 | cap_lower(cred->cap_effective, CAP_SYS_RESOURCE); | |
1893 | ||
655042cc | 1894 | sb->s_magic = OVERLAYFS_SUPER_MAGIC; |
655042cc | 1895 | sb->s_xattr = ovl_xattr_handlers; |
ad204488 | 1896 | sb->s_fs_info = ofs; |
de2a4a50 | 1897 | sb->s_flags |= SB_POSIXACL; |
32b1924b | 1898 | sb->s_iflags |= SB_I_SKIP_SYNC; |
655042cc | 1899 | |
c6fe6254 | 1900 | err = -ENOMEM; |
2effc5c2 | 1901 | root_dentry = ovl_get_root(sb, upperpath.dentry, oe); |
e9be9d5e | 1902 | if (!root_dentry) |
4155c10a | 1903 | goto out_free_oe; |
e9be9d5e MS |
1904 | |
1905 | mntput(upperpath.mnt); | |
ed06e069 | 1906 | |
e9be9d5e | 1907 | sb->s_root = root_dentry; |
e9be9d5e MS |
1908 | |
1909 | return 0; | |
1910 | ||
4155c10a MS |
1911 | out_free_oe: |
1912 | ovl_entry_stack_free(oe); | |
b9343632 | 1913 | kfree(oe); |
4155c10a | 1914 | out_err: |
e9be9d5e | 1915 | path_put(&upperpath); |
ad204488 | 1916 | ovl_free_fs(ofs); |
e9be9d5e MS |
1917 | out: |
1918 | return err; | |
1919 | } | |
1920 | ||
1921 | static struct dentry *ovl_mount(struct file_system_type *fs_type, int flags, | |
1922 | const char *dev_name, void *raw_data) | |
1923 | { | |
1924 | return mount_nodev(fs_type, flags, raw_data, ovl_fill_super); | |
1925 | } | |
1926 | ||
1927 | static struct file_system_type ovl_fs_type = { | |
1928 | .owner = THIS_MODULE, | |
ef94b186 | 1929 | .name = "overlay", |
e9be9d5e MS |
1930 | .mount = ovl_mount, |
1931 | .kill_sb = kill_anon_super, | |
1932 | }; | |
ef94b186 | 1933 | MODULE_ALIAS_FS("overlay"); |
e9be9d5e | 1934 | |
13cf199d AG |
1935 | static void ovl_inode_init_once(void *foo) |
1936 | { | |
1937 | struct ovl_inode *oi = foo; | |
1938 | ||
1939 | inode_init_once(&oi->vfs_inode); | |
1940 | } | |
1941 | ||
e9be9d5e MS |
1942 | static int __init ovl_init(void) |
1943 | { | |
13cf199d AG |
1944 | int err; |
1945 | ||
1946 | ovl_inode_cachep = kmem_cache_create("ovl_inode", | |
1947 | sizeof(struct ovl_inode), 0, | |
1948 | (SLAB_RECLAIM_ACCOUNT| | |
1949 | SLAB_MEM_SPREAD|SLAB_ACCOUNT), | |
1950 | ovl_inode_init_once); | |
1951 | if (ovl_inode_cachep == NULL) | |
1952 | return -ENOMEM; | |
1953 | ||
2406a307 JX |
1954 | err = ovl_aio_request_cache_init(); |
1955 | if (!err) { | |
1956 | err = register_filesystem(&ovl_fs_type); | |
1957 | if (!err) | |
1958 | return 0; | |
1959 | ||
1960 | ovl_aio_request_cache_destroy(); | |
1961 | } | |
1962 | kmem_cache_destroy(ovl_inode_cachep); | |
13cf199d AG |
1963 | |
1964 | return err; | |
e9be9d5e MS |
1965 | } |
1966 | ||
1967 | static void __exit ovl_exit(void) | |
1968 | { | |
1969 | unregister_filesystem(&ovl_fs_type); | |
13cf199d AG |
1970 | |
1971 | /* | |
1972 | * Make sure all delayed rcu free inodes are flushed before we | |
1973 | * destroy cache. | |
1974 | */ | |
1975 | rcu_barrier(); | |
1976 | kmem_cache_destroy(ovl_inode_cachep); | |
2406a307 | 1977 | ovl_aio_request_cache_destroy(); |
e9be9d5e MS |
1978 | } |
1979 | ||
1980 | module_init(ovl_init); | |
1981 | module_exit(ovl_exit); |