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Commit | Line | Data |
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e9be9d5e MS |
1 | /* |
2 | * | |
3 | * Copyright (C) 2011 Novell Inc. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License version 2 as published by | |
7 | * the Free Software Foundation. | |
8 | */ | |
9 | ||
5b825c3a | 10 | #include <uapi/linux/magic.h> |
e9be9d5e MS |
11 | #include <linux/fs.h> |
12 | #include <linux/namei.h> | |
13 | #include <linux/xattr.h> | |
e9be9d5e | 14 | #include <linux/mount.h> |
e9be9d5e MS |
15 | #include <linux/parser.h> |
16 | #include <linux/module.h> | |
cc259639 | 17 | #include <linux/statfs.h> |
f45827e8 | 18 | #include <linux/seq_file.h> |
d837a49b | 19 | #include <linux/posix_acl_xattr.h> |
e487d889 | 20 | #include <linux/exportfs.h> |
e9be9d5e MS |
21 | #include "overlayfs.h" |
22 | ||
23 | MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); | |
24 | MODULE_DESCRIPTION("Overlay filesystem"); | |
25 | MODULE_LICENSE("GPL"); | |
26 | ||
e9be9d5e MS |
27 | |
28 | struct ovl_dir_cache; | |
29 | ||
a78d9f0d MS |
30 | #define OVL_MAX_STACK 500 |
31 | ||
688ea0e5 MS |
32 | static bool ovl_redirect_dir_def = IS_ENABLED(CONFIG_OVERLAY_FS_REDIRECT_DIR); |
33 | module_param_named(redirect_dir, ovl_redirect_dir_def, bool, 0644); | |
34 | MODULE_PARM_DESC(ovl_redirect_dir_def, | |
35 | "Default to on or off for the redirect_dir feature"); | |
e9be9d5e | 36 | |
438c84c2 MS |
37 | static bool ovl_redirect_always_follow = |
38 | IS_ENABLED(CONFIG_OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW); | |
39 | module_param_named(redirect_always_follow, ovl_redirect_always_follow, | |
40 | bool, 0644); | |
41 | MODULE_PARM_DESC(ovl_redirect_always_follow, | |
42 | "Follow redirects even if redirect_dir feature is turned off"); | |
43 | ||
02bcd157 AG |
44 | static bool ovl_index_def = IS_ENABLED(CONFIG_OVERLAY_FS_INDEX); |
45 | module_param_named(index, ovl_index_def, bool, 0644); | |
46 | MODULE_PARM_DESC(ovl_index_def, | |
47 | "Default to on or off for the inodes index feature"); | |
48 | ||
f168f109 AG |
49 | static bool ovl_nfs_export_def = IS_ENABLED(CONFIG_OVERLAY_FS_NFS_EXPORT); |
50 | module_param_named(nfs_export, ovl_nfs_export_def, bool, 0644); | |
51 | MODULE_PARM_DESC(ovl_nfs_export_def, | |
52 | "Default to on or off for the NFS export feature"); | |
53 | ||
795939a9 AG |
54 | static bool ovl_xino_auto_def = IS_ENABLED(CONFIG_OVERLAY_FS_XINO_AUTO); |
55 | module_param_named(xino_auto, ovl_xino_auto_def, bool, 0644); | |
56 | MODULE_PARM_DESC(ovl_xino_auto_def, | |
57 | "Auto enable xino feature"); | |
58 | ||
4155c10a MS |
59 | static void ovl_entry_stack_free(struct ovl_entry *oe) |
60 | { | |
61 | unsigned int i; | |
62 | ||
63 | for (i = 0; i < oe->numlower; i++) | |
64 | dput(oe->lowerstack[i].dentry); | |
65 | } | |
66 | ||
d5791044 VG |
67 | static bool ovl_metacopy_def = IS_ENABLED(CONFIG_OVERLAY_FS_METACOPY); |
68 | module_param_named(metacopy, ovl_metacopy_def, bool, 0644); | |
69 | MODULE_PARM_DESC(ovl_metacopy_def, | |
70 | "Default to on or off for the metadata only copy up feature"); | |
71 | ||
e9be9d5e MS |
72 | static void ovl_dentry_release(struct dentry *dentry) |
73 | { | |
74 | struct ovl_entry *oe = dentry->d_fsdata; | |
75 | ||
76 | if (oe) { | |
4155c10a | 77 | ovl_entry_stack_free(oe); |
e9be9d5e MS |
78 | kfree_rcu(oe, rcu); |
79 | } | |
80 | } | |
81 | ||
2d902671 | 82 | static struct dentry *ovl_d_real(struct dentry *dentry, |
fb16043b | 83 | const struct inode *inode) |
d101a125 MS |
84 | { |
85 | struct dentry *real; | |
86 | ||
e8c985ba MS |
87 | /* It's an overlay file */ |
88 | if (inode && d_inode(dentry) == inode) | |
89 | return dentry; | |
90 | ||
ca4c8a3a | 91 | if (!d_is_reg(dentry)) { |
d101a125 MS |
92 | if (!inode || inode == d_inode(dentry)) |
93 | return dentry; | |
94 | goto bug; | |
95 | } | |
96 | ||
97 | real = ovl_dentry_upper(dentry); | |
fb16043b | 98 | if (real && (!inode || inode == d_inode(real))) |
d101a125 MS |
99 | return real; |
100 | ||
101 | real = ovl_dentry_lower(dentry); | |
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 | ||
7c03b5d4 MS |
116 | static int ovl_dentry_revalidate(struct dentry *dentry, unsigned int flags) |
117 | { | |
118 | struct ovl_entry *oe = dentry->d_fsdata; | |
119 | unsigned int i; | |
120 | int ret = 1; | |
121 | ||
122 | for (i = 0; i < oe->numlower; i++) { | |
123 | struct dentry *d = oe->lowerstack[i].dentry; | |
124 | ||
125 | if (d->d_flags & DCACHE_OP_REVALIDATE) { | |
126 | ret = d->d_op->d_revalidate(d, flags); | |
127 | if (ret < 0) | |
128 | return ret; | |
129 | if (!ret) { | |
130 | if (!(flags & LOOKUP_RCU)) | |
131 | d_invalidate(d); | |
132 | return -ESTALE; | |
133 | } | |
134 | } | |
135 | } | |
136 | return 1; | |
137 | } | |
138 | ||
139 | static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags) | |
140 | { | |
141 | struct ovl_entry *oe = dentry->d_fsdata; | |
142 | unsigned int i; | |
143 | int ret = 1; | |
144 | ||
145 | for (i = 0; i < oe->numlower; i++) { | |
146 | struct dentry *d = oe->lowerstack[i].dentry; | |
147 | ||
148 | if (d->d_flags & DCACHE_OP_WEAK_REVALIDATE) { | |
149 | ret = d->d_op->d_weak_revalidate(d, flags); | |
150 | if (ret <= 0) | |
151 | break; | |
152 | } | |
153 | } | |
154 | return ret; | |
155 | } | |
156 | ||
e9be9d5e MS |
157 | static const struct dentry_operations ovl_dentry_operations = { |
158 | .d_release = ovl_dentry_release, | |
d101a125 | 159 | .d_real = ovl_d_real, |
e9be9d5e MS |
160 | }; |
161 | ||
7c03b5d4 MS |
162 | static const struct dentry_operations ovl_reval_dentry_operations = { |
163 | .d_release = ovl_dentry_release, | |
d101a125 | 164 | .d_real = ovl_d_real, |
7c03b5d4 MS |
165 | .d_revalidate = ovl_dentry_revalidate, |
166 | .d_weak_revalidate = ovl_dentry_weak_revalidate, | |
167 | }; | |
168 | ||
13cf199d AG |
169 | static struct kmem_cache *ovl_inode_cachep; |
170 | ||
171 | static struct inode *ovl_alloc_inode(struct super_block *sb) | |
172 | { | |
173 | struct ovl_inode *oi = kmem_cache_alloc(ovl_inode_cachep, GFP_KERNEL); | |
174 | ||
b3885bd6 HN |
175 | if (!oi) |
176 | return NULL; | |
177 | ||
04a01ac7 | 178 | oi->cache = NULL; |
cf31c463 | 179 | oi->redirect = NULL; |
04a01ac7 | 180 | oi->version = 0; |
13c72075 | 181 | oi->flags = 0; |
09d8b586 | 182 | oi->__upperdentry = NULL; |
25b7713a | 183 | oi->lower = NULL; |
a015dafc | 184 | mutex_init(&oi->lock); |
25b7713a | 185 | |
13cf199d AG |
186 | return &oi->vfs_inode; |
187 | } | |
188 | ||
189 | static void ovl_i_callback(struct rcu_head *head) | |
190 | { | |
191 | struct inode *inode = container_of(head, struct inode, i_rcu); | |
192 | ||
193 | kmem_cache_free(ovl_inode_cachep, OVL_I(inode)); | |
194 | } | |
195 | ||
196 | static void ovl_destroy_inode(struct inode *inode) | |
197 | { | |
09d8b586 MS |
198 | struct ovl_inode *oi = OVL_I(inode); |
199 | ||
200 | dput(oi->__upperdentry); | |
31747eda | 201 | iput(oi->lower); |
cf31c463 | 202 | kfree(oi->redirect); |
4edb83bb | 203 | ovl_dir_cache_free(inode); |
a015dafc | 204 | mutex_destroy(&oi->lock); |
09d8b586 | 205 | |
13cf199d AG |
206 | call_rcu(&inode->i_rcu, ovl_i_callback); |
207 | } | |
208 | ||
ad204488 | 209 | static void ovl_free_fs(struct ovl_fs *ofs) |
e9be9d5e | 210 | { |
dd662667 | 211 | unsigned i; |
e9be9d5e | 212 | |
ad204488 MS |
213 | dput(ofs->indexdir); |
214 | dput(ofs->workdir); | |
215 | if (ofs->workdir_locked) | |
216 | ovl_inuse_unlock(ofs->workbasedir); | |
217 | dput(ofs->workbasedir); | |
218 | if (ofs->upperdir_locked) | |
219 | ovl_inuse_unlock(ofs->upper_mnt->mnt_root); | |
220 | mntput(ofs->upper_mnt); | |
5148626b | 221 | for (i = 0; i < ofs->numlower; i++) |
ad204488 | 222 | mntput(ofs->lower_layers[i].mnt); |
5148626b AG |
223 | for (i = 0; i < ofs->numlowerfs; i++) |
224 | free_anon_bdev(ofs->lower_fs[i].pseudo_dev); | |
ad204488 | 225 | kfree(ofs->lower_layers); |
5148626b | 226 | kfree(ofs->lower_fs); |
ad204488 MS |
227 | |
228 | kfree(ofs->config.lowerdir); | |
229 | kfree(ofs->config.upperdir); | |
230 | kfree(ofs->config.workdir); | |
438c84c2 | 231 | kfree(ofs->config.redirect_mode); |
ad204488 MS |
232 | if (ofs->creator_cred) |
233 | put_cred(ofs->creator_cred); | |
234 | kfree(ofs); | |
e9be9d5e MS |
235 | } |
236 | ||
a9075cdb MS |
237 | static void ovl_put_super(struct super_block *sb) |
238 | { | |
239 | struct ovl_fs *ofs = sb->s_fs_info; | |
240 | ||
241 | ovl_free_fs(ofs); | |
242 | } | |
243 | ||
e8d4bfe3 | 244 | /* Sync real dirty inodes in upper filesystem (if it exists) */ |
e593b2bf AG |
245 | static int ovl_sync_fs(struct super_block *sb, int wait) |
246 | { | |
ad204488 | 247 | struct ovl_fs *ofs = sb->s_fs_info; |
e593b2bf AG |
248 | struct super_block *upper_sb; |
249 | int ret; | |
250 | ||
ad204488 | 251 | if (!ofs->upper_mnt) |
e593b2bf | 252 | return 0; |
e8d4bfe3 CX |
253 | |
254 | /* | |
255 | * If this is a sync(2) call or an emergency sync, all the super blocks | |
256 | * will be iterated, including upper_sb, so no need to do anything. | |
257 | * | |
258 | * If this is a syncfs(2) call, then we do need to call | |
259 | * sync_filesystem() on upper_sb, but enough if we do it when being | |
260 | * called with wait == 1. | |
261 | */ | |
262 | if (!wait) | |
e593b2bf AG |
263 | return 0; |
264 | ||
e8d4bfe3 CX |
265 | upper_sb = ofs->upper_mnt->mnt_sb; |
266 | ||
e593b2bf | 267 | down_read(&upper_sb->s_umount); |
e8d4bfe3 | 268 | ret = sync_filesystem(upper_sb); |
e593b2bf | 269 | up_read(&upper_sb->s_umount); |
e8d4bfe3 | 270 | |
e593b2bf AG |
271 | return ret; |
272 | } | |
273 | ||
cc259639 AW |
274 | /** |
275 | * ovl_statfs | |
276 | * @sb: The overlayfs super block | |
277 | * @buf: The struct kstatfs to fill in with stats | |
278 | * | |
279 | * Get the filesystem statistics. As writes always target the upper layer | |
4ebc5818 | 280 | * filesystem pass the statfs to the upper filesystem (if it exists) |
cc259639 AW |
281 | */ |
282 | static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf) | |
283 | { | |
284 | struct ovl_fs *ofs = dentry->d_sb->s_fs_info; | |
285 | struct dentry *root_dentry = dentry->d_sb->s_root; | |
286 | struct path path; | |
287 | int err; | |
288 | ||
4ebc5818 | 289 | ovl_path_real(root_dentry, &path); |
cc259639 AW |
290 | |
291 | err = vfs_statfs(&path, buf); | |
292 | if (!err) { | |
6b2d5fe4 | 293 | buf->f_namelen = ofs->namelen; |
cc259639 AW |
294 | buf->f_type = OVERLAYFS_SUPER_MAGIC; |
295 | } | |
296 | ||
297 | return err; | |
298 | } | |
299 | ||
02bcd157 | 300 | /* Will this overlay be forced to mount/remount ro? */ |
ad204488 | 301 | static bool ovl_force_readonly(struct ovl_fs *ofs) |
02bcd157 | 302 | { |
ad204488 | 303 | return (!ofs->upper_mnt || !ofs->workdir); |
02bcd157 AG |
304 | } |
305 | ||
438c84c2 MS |
306 | static const char *ovl_redirect_mode_def(void) |
307 | { | |
308 | return ovl_redirect_dir_def ? "on" : "off"; | |
309 | } | |
310 | ||
795939a9 AG |
311 | enum { |
312 | OVL_XINO_OFF, | |
313 | OVL_XINO_AUTO, | |
314 | OVL_XINO_ON, | |
315 | }; | |
316 | ||
317 | static const char * const ovl_xino_str[] = { | |
318 | "off", | |
319 | "auto", | |
320 | "on", | |
321 | }; | |
322 | ||
323 | static inline int ovl_xino_def(void) | |
324 | { | |
325 | return ovl_xino_auto_def ? OVL_XINO_AUTO : OVL_XINO_OFF; | |
326 | } | |
327 | ||
f45827e8 EZ |
328 | /** |
329 | * ovl_show_options | |
330 | * | |
331 | * Prints the mount options for a given superblock. | |
332 | * Returns zero; does not fail. | |
333 | */ | |
334 | static int ovl_show_options(struct seq_file *m, struct dentry *dentry) | |
335 | { | |
336 | struct super_block *sb = dentry->d_sb; | |
ad204488 | 337 | struct ovl_fs *ofs = sb->s_fs_info; |
f45827e8 | 338 | |
ad204488 MS |
339 | seq_show_option(m, "lowerdir", ofs->config.lowerdir); |
340 | if (ofs->config.upperdir) { | |
341 | seq_show_option(m, "upperdir", ofs->config.upperdir); | |
342 | seq_show_option(m, "workdir", ofs->config.workdir); | |
53a08cb9 | 343 | } |
ad204488 | 344 | if (ofs->config.default_permissions) |
8d3095f4 | 345 | seq_puts(m, ",default_permissions"); |
438c84c2 MS |
346 | if (strcmp(ofs->config.redirect_mode, ovl_redirect_mode_def()) != 0) |
347 | seq_printf(m, ",redirect_dir=%s", ofs->config.redirect_mode); | |
ad204488 | 348 | if (ofs->config.index != ovl_index_def) |
438c84c2 | 349 | seq_printf(m, ",index=%s", ofs->config.index ? "on" : "off"); |
f168f109 AG |
350 | if (ofs->config.nfs_export != ovl_nfs_export_def) |
351 | seq_printf(m, ",nfs_export=%s", ofs->config.nfs_export ? | |
352 | "on" : "off"); | |
795939a9 AG |
353 | if (ofs->config.xino != ovl_xino_def()) |
354 | seq_printf(m, ",xino=%s", ovl_xino_str[ofs->config.xino]); | |
d5791044 VG |
355 | if (ofs->config.metacopy != ovl_metacopy_def) |
356 | seq_printf(m, ",metacopy=%s", | |
357 | ofs->config.metacopy ? "on" : "off"); | |
f45827e8 EZ |
358 | return 0; |
359 | } | |
360 | ||
3cdf6fe9 SL |
361 | static int ovl_remount(struct super_block *sb, int *flags, char *data) |
362 | { | |
ad204488 | 363 | struct ovl_fs *ofs = sb->s_fs_info; |
3cdf6fe9 | 364 | |
1751e8a6 | 365 | if (!(*flags & SB_RDONLY) && ovl_force_readonly(ofs)) |
3cdf6fe9 SL |
366 | return -EROFS; |
367 | ||
368 | return 0; | |
369 | } | |
370 | ||
e9be9d5e | 371 | static const struct super_operations ovl_super_operations = { |
13cf199d AG |
372 | .alloc_inode = ovl_alloc_inode, |
373 | .destroy_inode = ovl_destroy_inode, | |
374 | .drop_inode = generic_delete_inode, | |
e9be9d5e | 375 | .put_super = ovl_put_super, |
e593b2bf | 376 | .sync_fs = ovl_sync_fs, |
cc259639 | 377 | .statfs = ovl_statfs, |
f45827e8 | 378 | .show_options = ovl_show_options, |
3cdf6fe9 | 379 | .remount_fs = ovl_remount, |
e9be9d5e MS |
380 | }; |
381 | ||
382 | enum { | |
383 | OPT_LOWERDIR, | |
384 | OPT_UPPERDIR, | |
385 | OPT_WORKDIR, | |
8d3095f4 | 386 | OPT_DEFAULT_PERMISSIONS, |
438c84c2 | 387 | OPT_REDIRECT_DIR, |
02bcd157 AG |
388 | OPT_INDEX_ON, |
389 | OPT_INDEX_OFF, | |
f168f109 AG |
390 | OPT_NFS_EXPORT_ON, |
391 | OPT_NFS_EXPORT_OFF, | |
795939a9 AG |
392 | OPT_XINO_ON, |
393 | OPT_XINO_OFF, | |
394 | OPT_XINO_AUTO, | |
d5791044 VG |
395 | OPT_METACOPY_ON, |
396 | OPT_METACOPY_OFF, | |
e9be9d5e MS |
397 | OPT_ERR, |
398 | }; | |
399 | ||
400 | static const match_table_t ovl_tokens = { | |
401 | {OPT_LOWERDIR, "lowerdir=%s"}, | |
402 | {OPT_UPPERDIR, "upperdir=%s"}, | |
403 | {OPT_WORKDIR, "workdir=%s"}, | |
8d3095f4 | 404 | {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, |
438c84c2 | 405 | {OPT_REDIRECT_DIR, "redirect_dir=%s"}, |
02bcd157 AG |
406 | {OPT_INDEX_ON, "index=on"}, |
407 | {OPT_INDEX_OFF, "index=off"}, | |
f168f109 AG |
408 | {OPT_NFS_EXPORT_ON, "nfs_export=on"}, |
409 | {OPT_NFS_EXPORT_OFF, "nfs_export=off"}, | |
795939a9 AG |
410 | {OPT_XINO_ON, "xino=on"}, |
411 | {OPT_XINO_OFF, "xino=off"}, | |
412 | {OPT_XINO_AUTO, "xino=auto"}, | |
d5791044 VG |
413 | {OPT_METACOPY_ON, "metacopy=on"}, |
414 | {OPT_METACOPY_OFF, "metacopy=off"}, | |
e9be9d5e MS |
415 | {OPT_ERR, NULL} |
416 | }; | |
417 | ||
91c77947 MS |
418 | static char *ovl_next_opt(char **s) |
419 | { | |
420 | char *sbegin = *s; | |
421 | char *p; | |
422 | ||
423 | if (sbegin == NULL) | |
424 | return NULL; | |
425 | ||
426 | for (p = sbegin; *p; p++) { | |
427 | if (*p == '\\') { | |
428 | p++; | |
429 | if (!*p) | |
430 | break; | |
431 | } else if (*p == ',') { | |
432 | *p = '\0'; | |
433 | *s = p + 1; | |
434 | return sbegin; | |
435 | } | |
436 | } | |
437 | *s = NULL; | |
438 | return sbegin; | |
439 | } | |
440 | ||
438c84c2 MS |
441 | static int ovl_parse_redirect_mode(struct ovl_config *config, const char *mode) |
442 | { | |
443 | if (strcmp(mode, "on") == 0) { | |
444 | config->redirect_dir = true; | |
445 | /* | |
446 | * Does not make sense to have redirect creation without | |
447 | * redirect following. | |
448 | */ | |
449 | config->redirect_follow = true; | |
450 | } else if (strcmp(mode, "follow") == 0) { | |
451 | config->redirect_follow = true; | |
452 | } else if (strcmp(mode, "off") == 0) { | |
453 | if (ovl_redirect_always_follow) | |
454 | config->redirect_follow = true; | |
455 | } else if (strcmp(mode, "nofollow") != 0) { | |
456 | pr_err("overlayfs: bad mount option \"redirect_dir=%s\"\n", | |
457 | mode); | |
458 | return -EINVAL; | |
459 | } | |
460 | ||
461 | return 0; | |
462 | } | |
463 | ||
e9be9d5e MS |
464 | static int ovl_parse_opt(char *opt, struct ovl_config *config) |
465 | { | |
466 | char *p; | |
d5791044 | 467 | int err; |
e9be9d5e | 468 | |
438c84c2 MS |
469 | config->redirect_mode = kstrdup(ovl_redirect_mode_def(), GFP_KERNEL); |
470 | if (!config->redirect_mode) | |
471 | return -ENOMEM; | |
472 | ||
91c77947 | 473 | while ((p = ovl_next_opt(&opt)) != NULL) { |
e9be9d5e MS |
474 | int token; |
475 | substring_t args[MAX_OPT_ARGS]; | |
476 | ||
477 | if (!*p) | |
478 | continue; | |
479 | ||
480 | token = match_token(p, ovl_tokens, args); | |
481 | switch (token) { | |
482 | case OPT_UPPERDIR: | |
483 | kfree(config->upperdir); | |
484 | config->upperdir = match_strdup(&args[0]); | |
485 | if (!config->upperdir) | |
486 | return -ENOMEM; | |
487 | break; | |
488 | ||
489 | case OPT_LOWERDIR: | |
490 | kfree(config->lowerdir); | |
491 | config->lowerdir = match_strdup(&args[0]); | |
492 | if (!config->lowerdir) | |
493 | return -ENOMEM; | |
494 | break; | |
495 | ||
496 | case OPT_WORKDIR: | |
497 | kfree(config->workdir); | |
498 | config->workdir = match_strdup(&args[0]); | |
499 | if (!config->workdir) | |
500 | return -ENOMEM; | |
501 | break; | |
502 | ||
8d3095f4 MS |
503 | case OPT_DEFAULT_PERMISSIONS: |
504 | config->default_permissions = true; | |
505 | break; | |
506 | ||
438c84c2 MS |
507 | case OPT_REDIRECT_DIR: |
508 | kfree(config->redirect_mode); | |
509 | config->redirect_mode = match_strdup(&args[0]); | |
510 | if (!config->redirect_mode) | |
511 | return -ENOMEM; | |
a6c60655 MS |
512 | break; |
513 | ||
02bcd157 AG |
514 | case OPT_INDEX_ON: |
515 | config->index = true; | |
516 | break; | |
517 | ||
518 | case OPT_INDEX_OFF: | |
519 | config->index = false; | |
520 | break; | |
521 | ||
f168f109 AG |
522 | case OPT_NFS_EXPORT_ON: |
523 | config->nfs_export = true; | |
524 | break; | |
525 | ||
526 | case OPT_NFS_EXPORT_OFF: | |
527 | config->nfs_export = false; | |
528 | break; | |
529 | ||
795939a9 AG |
530 | case OPT_XINO_ON: |
531 | config->xino = OVL_XINO_ON; | |
532 | break; | |
533 | ||
534 | case OPT_XINO_OFF: | |
535 | config->xino = OVL_XINO_OFF; | |
536 | break; | |
537 | ||
538 | case OPT_XINO_AUTO: | |
539 | config->xino = OVL_XINO_AUTO; | |
540 | break; | |
541 | ||
d5791044 VG |
542 | case OPT_METACOPY_ON: |
543 | config->metacopy = true; | |
544 | break; | |
545 | ||
546 | case OPT_METACOPY_OFF: | |
547 | config->metacopy = false; | |
548 | break; | |
549 | ||
e9be9d5e | 550 | default: |
bead55ef | 551 | pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p); |
e9be9d5e MS |
552 | return -EINVAL; |
553 | } | |
554 | } | |
71cbad7e | 555 | |
556 | /* Workdir is useless in non-upper mount */ | |
557 | if (!config->upperdir && config->workdir) { | |
558 | pr_info("overlayfs: option \"workdir=%s\" is useless in a non-upper mount, ignore\n", | |
559 | config->workdir); | |
560 | kfree(config->workdir); | |
561 | config->workdir = NULL; | |
562 | } | |
563 | ||
d5791044 VG |
564 | err = ovl_parse_redirect_mode(config, config->redirect_mode); |
565 | if (err) | |
566 | return err; | |
567 | ||
568 | /* metacopy feature with upper requires redirect_dir=on */ | |
569 | if (config->upperdir && config->metacopy && !config->redirect_dir) { | |
570 | pr_warn("overlayfs: metadata only copy up requires \"redirect_dir=on\", falling back to metacopy=off.\n"); | |
571 | config->metacopy = false; | |
572 | } else if (config->metacopy && !config->redirect_follow) { | |
573 | pr_warn("overlayfs: metadata only copy up requires \"redirect_dir=follow\" on non-upper mount, falling back to metacopy=off.\n"); | |
574 | config->metacopy = false; | |
575 | } | |
576 | ||
577 | return 0; | |
e9be9d5e MS |
578 | } |
579 | ||
580 | #define OVL_WORKDIR_NAME "work" | |
02bcd157 | 581 | #define OVL_INDEXDIR_NAME "index" |
e9be9d5e | 582 | |
ad204488 | 583 | static struct dentry *ovl_workdir_create(struct ovl_fs *ofs, |
6b8aa129 | 584 | const char *name, bool persist) |
e9be9d5e | 585 | { |
ad204488 MS |
586 | struct inode *dir = ofs->workbasedir->d_inode; |
587 | struct vfsmount *mnt = ofs->upper_mnt; | |
e9be9d5e MS |
588 | struct dentry *work; |
589 | int err; | |
590 | bool retried = false; | |
6b8aa129 | 591 | bool locked = false; |
e9be9d5e | 592 | |
5955102c | 593 | inode_lock_nested(dir, I_MUTEX_PARENT); |
6b8aa129 AG |
594 | locked = true; |
595 | ||
e9be9d5e | 596 | retry: |
ad204488 | 597 | work = lookup_one_len(name, ofs->workbasedir, strlen(name)); |
e9be9d5e MS |
598 | |
599 | if (!IS_ERR(work)) { | |
c11b9fdd MS |
600 | struct iattr attr = { |
601 | .ia_valid = ATTR_MODE, | |
32a3d848 | 602 | .ia_mode = S_IFDIR | 0, |
c11b9fdd | 603 | }; |
e9be9d5e MS |
604 | |
605 | if (work->d_inode) { | |
606 | err = -EEXIST; | |
607 | if (retried) | |
608 | goto out_dput; | |
609 | ||
6b8aa129 AG |
610 | if (persist) |
611 | goto out_unlock; | |
612 | ||
e9be9d5e | 613 | retried = true; |
eea2fb48 | 614 | ovl_workdir_cleanup(dir, mnt, work, 0); |
e9be9d5e MS |
615 | dput(work); |
616 | goto retry; | |
617 | } | |
618 | ||
95a1c815 MS |
619 | work = ovl_create_real(dir, work, OVL_CATTR(attr.ia_mode)); |
620 | err = PTR_ERR(work); | |
621 | if (IS_ERR(work)) | |
622 | goto out_err; | |
c11b9fdd | 623 | |
cb348edb MS |
624 | /* |
625 | * Try to remove POSIX ACL xattrs from workdir. We are good if: | |
626 | * | |
627 | * a) success (there was a POSIX ACL xattr and was removed) | |
628 | * b) -ENODATA (there was no POSIX ACL xattr) | |
629 | * c) -EOPNOTSUPP (POSIX ACL xattrs are not supported) | |
630 | * | |
631 | * There are various other error values that could effectively | |
632 | * mean that the xattr doesn't exist (e.g. -ERANGE is returned | |
633 | * if the xattr name is too long), but the set of filesystems | |
634 | * allowed as upper are limited to "normal" ones, where checking | |
635 | * for the above two errors is sufficient. | |
636 | */ | |
c11b9fdd | 637 | err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT); |
e1ff3dd1 | 638 | if (err && err != -ENODATA && err != -EOPNOTSUPP) |
c11b9fdd MS |
639 | goto out_dput; |
640 | ||
641 | err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_ACCESS); | |
e1ff3dd1 | 642 | if (err && err != -ENODATA && err != -EOPNOTSUPP) |
c11b9fdd MS |
643 | goto out_dput; |
644 | ||
645 | /* Clear any inherited mode bits */ | |
646 | inode_lock(work->d_inode); | |
647 | err = notify_change(work, &attr, NULL); | |
648 | inode_unlock(work->d_inode); | |
649 | if (err) | |
650 | goto out_dput; | |
6b8aa129 AG |
651 | } else { |
652 | err = PTR_ERR(work); | |
653 | goto out_err; | |
e9be9d5e MS |
654 | } |
655 | out_unlock: | |
6b8aa129 AG |
656 | if (locked) |
657 | inode_unlock(dir); | |
e9be9d5e MS |
658 | |
659 | return work; | |
660 | ||
661 | out_dput: | |
662 | dput(work); | |
6b8aa129 AG |
663 | out_err: |
664 | pr_warn("overlayfs: failed to create directory %s/%s (errno: %i); mounting read-only\n", | |
ad204488 | 665 | ofs->config.workdir, name, -err); |
6b8aa129 | 666 | work = NULL; |
e9be9d5e MS |
667 | goto out_unlock; |
668 | } | |
669 | ||
91c77947 MS |
670 | static void ovl_unescape(char *s) |
671 | { | |
672 | char *d = s; | |
673 | ||
674 | for (;; s++, d++) { | |
675 | if (*s == '\\') | |
676 | s++; | |
677 | *d = *s; | |
678 | if (!*s) | |
679 | break; | |
680 | } | |
681 | } | |
682 | ||
ab508822 MS |
683 | static int ovl_mount_dir_noesc(const char *name, struct path *path) |
684 | { | |
a78d9f0d | 685 | int err = -EINVAL; |
ab508822 | 686 | |
a78d9f0d MS |
687 | if (!*name) { |
688 | pr_err("overlayfs: empty lowerdir\n"); | |
689 | goto out; | |
690 | } | |
ab508822 MS |
691 | err = kern_path(name, LOOKUP_FOLLOW, path); |
692 | if (err) { | |
693 | pr_err("overlayfs: failed to resolve '%s': %i\n", name, err); | |
694 | goto out; | |
695 | } | |
696 | err = -EINVAL; | |
7c03b5d4 | 697 | if (ovl_dentry_weird(path->dentry)) { |
ab508822 MS |
698 | pr_err("overlayfs: filesystem on '%s' not supported\n", name); |
699 | goto out_put; | |
700 | } | |
2b8c30e9 | 701 | if (!d_is_dir(path->dentry)) { |
ab508822 MS |
702 | pr_err("overlayfs: '%s' not a directory\n", name); |
703 | goto out_put; | |
704 | } | |
705 | return 0; | |
706 | ||
707 | out_put: | |
8aafcb59 | 708 | path_put_init(path); |
ab508822 MS |
709 | out: |
710 | return err; | |
711 | } | |
712 | ||
713 | static int ovl_mount_dir(const char *name, struct path *path) | |
714 | { | |
715 | int err = -ENOMEM; | |
716 | char *tmp = kstrdup(name, GFP_KERNEL); | |
717 | ||
718 | if (tmp) { | |
719 | ovl_unescape(tmp); | |
720 | err = ovl_mount_dir_noesc(tmp, path); | |
7c03b5d4 MS |
721 | |
722 | if (!err) | |
723 | if (ovl_dentry_remote(path->dentry)) { | |
724 | pr_err("overlayfs: filesystem on '%s' not supported as upperdir\n", | |
725 | tmp); | |
8aafcb59 | 726 | path_put_init(path); |
7c03b5d4 MS |
727 | err = -EINVAL; |
728 | } | |
ab508822 MS |
729 | kfree(tmp); |
730 | } | |
731 | return err; | |
732 | } | |
733 | ||
6b2d5fe4 MS |
734 | static int ovl_check_namelen(struct path *path, struct ovl_fs *ofs, |
735 | const char *name) | |
ab508822 | 736 | { |
ab508822 | 737 | struct kstatfs statfs; |
6b2d5fe4 MS |
738 | int err = vfs_statfs(path, &statfs); |
739 | ||
740 | if (err) | |
741 | pr_err("overlayfs: statfs failed on '%s'\n", name); | |
742 | else | |
743 | ofs->namelen = max(ofs->namelen, statfs.f_namelen); | |
744 | ||
745 | return err; | |
746 | } | |
747 | ||
748 | static int ovl_lower_dir(const char *name, struct path *path, | |
749 | struct ovl_fs *ofs, int *stack_depth, bool *remote) | |
750 | { | |
e487d889 | 751 | int fh_type; |
6b2d5fe4 | 752 | int err; |
ab508822 | 753 | |
a78d9f0d | 754 | err = ovl_mount_dir_noesc(name, path); |
ab508822 MS |
755 | if (err) |
756 | goto out; | |
757 | ||
6b2d5fe4 MS |
758 | err = ovl_check_namelen(path, ofs, name); |
759 | if (err) | |
ab508822 | 760 | goto out_put; |
6b2d5fe4 | 761 | |
ab508822 MS |
762 | *stack_depth = max(*stack_depth, path->mnt->mnt_sb->s_stack_depth); |
763 | ||
7c03b5d4 MS |
764 | if (ovl_dentry_remote(path->dentry)) |
765 | *remote = true; | |
766 | ||
02bcd157 | 767 | /* |
f168f109 AG |
768 | * The inodes index feature and NFS export need to encode and decode |
769 | * file handles, so they require that all layers support them. | |
02bcd157 | 770 | */ |
e487d889 | 771 | fh_type = ovl_can_decode_fh(path->dentry->d_sb); |
f168f109 | 772 | if ((ofs->config.nfs_export || |
e487d889 | 773 | (ofs->config.index && ofs->config.upperdir)) && !fh_type) { |
02bcd157 | 774 | ofs->config.index = false; |
f168f109 AG |
775 | ofs->config.nfs_export = false; |
776 | pr_warn("overlayfs: fs on '%s' does not support file handles, falling back to index=off,nfs_export=off.\n", | |
777 | name); | |
02bcd157 AG |
778 | } |
779 | ||
e487d889 AG |
780 | /* Check if lower fs has 32bit inode numbers */ |
781 | if (fh_type != FILEID_INO32_GEN) | |
782 | ofs->xino_bits = 0; | |
783 | ||
ab508822 MS |
784 | return 0; |
785 | ||
786 | out_put: | |
8aafcb59 | 787 | path_put_init(path); |
ab508822 MS |
788 | out: |
789 | return err; | |
790 | } | |
791 | ||
e9be9d5e MS |
792 | /* Workdir should not be subdir of upperdir and vice versa */ |
793 | static bool ovl_workdir_ok(struct dentry *workdir, struct dentry *upperdir) | |
794 | { | |
795 | bool ok = false; | |
796 | ||
797 | if (workdir != upperdir) { | |
798 | ok = (lock_rename(workdir, upperdir) == NULL); | |
799 | unlock_rename(workdir, upperdir); | |
800 | } | |
801 | return ok; | |
802 | } | |
803 | ||
a78d9f0d MS |
804 | static unsigned int ovl_split_lowerdirs(char *str) |
805 | { | |
806 | unsigned int ctr = 1; | |
807 | char *s, *d; | |
808 | ||
809 | for (s = d = str;; s++, d++) { | |
810 | if (*s == '\\') { | |
811 | s++; | |
812 | } else if (*s == ':') { | |
813 | *d = '\0'; | |
814 | ctr++; | |
815 | continue; | |
816 | } | |
817 | *d = *s; | |
818 | if (!*s) | |
819 | break; | |
820 | } | |
821 | return ctr; | |
822 | } | |
823 | ||
0eb45fc3 AG |
824 | static int __maybe_unused |
825 | ovl_posix_acl_xattr_get(const struct xattr_handler *handler, | |
826 | struct dentry *dentry, struct inode *inode, | |
827 | const char *name, void *buffer, size_t size) | |
828 | { | |
1d88f183 | 829 | return ovl_xattr_get(dentry, inode, handler->name, buffer, size); |
0eb45fc3 AG |
830 | } |
831 | ||
0c97be22 AG |
832 | static int __maybe_unused |
833 | ovl_posix_acl_xattr_set(const struct xattr_handler *handler, | |
834 | struct dentry *dentry, struct inode *inode, | |
835 | const char *name, const void *value, | |
836 | size_t size, int flags) | |
d837a49b MS |
837 | { |
838 | struct dentry *workdir = ovl_workdir(dentry); | |
09d8b586 | 839 | struct inode *realinode = ovl_inode_real(inode); |
d837a49b MS |
840 | struct posix_acl *acl = NULL; |
841 | int err; | |
842 | ||
843 | /* Check that everything is OK before copy-up */ | |
844 | if (value) { | |
845 | acl = posix_acl_from_xattr(&init_user_ns, value, size); | |
846 | if (IS_ERR(acl)) | |
847 | return PTR_ERR(acl); | |
848 | } | |
849 | err = -EOPNOTSUPP; | |
850 | if (!IS_POSIXACL(d_inode(workdir))) | |
851 | goto out_acl_release; | |
852 | if (!realinode->i_op->set_acl) | |
853 | goto out_acl_release; | |
854 | if (handler->flags == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) { | |
855 | err = acl ? -EACCES : 0; | |
856 | goto out_acl_release; | |
857 | } | |
858 | err = -EPERM; | |
859 | if (!inode_owner_or_capable(inode)) | |
860 | goto out_acl_release; | |
861 | ||
862 | posix_acl_release(acl); | |
863 | ||
fd3220d3 MS |
864 | /* |
865 | * Check if sgid bit needs to be cleared (actual setacl operation will | |
866 | * be done with mounter's capabilities and so that won't do it for us). | |
867 | */ | |
868 | if (unlikely(inode->i_mode & S_ISGID) && | |
869 | handler->flags == ACL_TYPE_ACCESS && | |
870 | !in_group_p(inode->i_gid) && | |
871 | !capable_wrt_inode_uidgid(inode, CAP_FSETID)) { | |
872 | struct iattr iattr = { .ia_valid = ATTR_KILL_SGID }; | |
873 | ||
874 | err = ovl_setattr(dentry, &iattr); | |
875 | if (err) | |
876 | return err; | |
877 | } | |
878 | ||
1d88f183 | 879 | err = ovl_xattr_set(dentry, inode, handler->name, value, size, flags); |
ce31513a | 880 | if (!err) |
09d8b586 | 881 | ovl_copyattr(ovl_inode_real(inode), inode); |
ce31513a MS |
882 | |
883 | return err; | |
d837a49b MS |
884 | |
885 | out_acl_release: | |
886 | posix_acl_release(acl); | |
887 | return err; | |
888 | } | |
889 | ||
0eb45fc3 AG |
890 | static int ovl_own_xattr_get(const struct xattr_handler *handler, |
891 | struct dentry *dentry, struct inode *inode, | |
892 | const char *name, void *buffer, size_t size) | |
893 | { | |
48fab5d7 | 894 | return -EOPNOTSUPP; |
0eb45fc3 AG |
895 | } |
896 | ||
d837a49b MS |
897 | static int ovl_own_xattr_set(const struct xattr_handler *handler, |
898 | struct dentry *dentry, struct inode *inode, | |
899 | const char *name, const void *value, | |
900 | size_t size, int flags) | |
901 | { | |
48fab5d7 | 902 | return -EOPNOTSUPP; |
d837a49b MS |
903 | } |
904 | ||
0eb45fc3 AG |
905 | static int ovl_other_xattr_get(const struct xattr_handler *handler, |
906 | struct dentry *dentry, struct inode *inode, | |
907 | const char *name, void *buffer, size_t size) | |
908 | { | |
1d88f183 | 909 | return ovl_xattr_get(dentry, inode, name, buffer, size); |
0eb45fc3 AG |
910 | } |
911 | ||
0e585ccc AG |
912 | static int ovl_other_xattr_set(const struct xattr_handler *handler, |
913 | struct dentry *dentry, struct inode *inode, | |
914 | const char *name, const void *value, | |
915 | size_t size, int flags) | |
916 | { | |
1d88f183 | 917 | return ovl_xattr_set(dentry, inode, name, value, size, flags); |
0e585ccc AG |
918 | } |
919 | ||
0c97be22 AG |
920 | static const struct xattr_handler __maybe_unused |
921 | ovl_posix_acl_access_xattr_handler = { | |
d837a49b MS |
922 | .name = XATTR_NAME_POSIX_ACL_ACCESS, |
923 | .flags = ACL_TYPE_ACCESS, | |
0eb45fc3 | 924 | .get = ovl_posix_acl_xattr_get, |
d837a49b MS |
925 | .set = ovl_posix_acl_xattr_set, |
926 | }; | |
927 | ||
0c97be22 AG |
928 | static const struct xattr_handler __maybe_unused |
929 | ovl_posix_acl_default_xattr_handler = { | |
d837a49b MS |
930 | .name = XATTR_NAME_POSIX_ACL_DEFAULT, |
931 | .flags = ACL_TYPE_DEFAULT, | |
0eb45fc3 | 932 | .get = ovl_posix_acl_xattr_get, |
d837a49b MS |
933 | .set = ovl_posix_acl_xattr_set, |
934 | }; | |
935 | ||
936 | static const struct xattr_handler ovl_own_xattr_handler = { | |
937 | .prefix = OVL_XATTR_PREFIX, | |
0eb45fc3 | 938 | .get = ovl_own_xattr_get, |
d837a49b MS |
939 | .set = ovl_own_xattr_set, |
940 | }; | |
941 | ||
942 | static const struct xattr_handler ovl_other_xattr_handler = { | |
943 | .prefix = "", /* catch all */ | |
0eb45fc3 | 944 | .get = ovl_other_xattr_get, |
d837a49b MS |
945 | .set = ovl_other_xattr_set, |
946 | }; | |
947 | ||
948 | static const struct xattr_handler *ovl_xattr_handlers[] = { | |
0c97be22 | 949 | #ifdef CONFIG_FS_POSIX_ACL |
d837a49b MS |
950 | &ovl_posix_acl_access_xattr_handler, |
951 | &ovl_posix_acl_default_xattr_handler, | |
0c97be22 | 952 | #endif |
d837a49b MS |
953 | &ovl_own_xattr_handler, |
954 | &ovl_other_xattr_handler, | |
955 | NULL | |
956 | }; | |
957 | ||
ad204488 | 958 | static int ovl_get_upper(struct ovl_fs *ofs, struct path *upperpath) |
6ee8acf0 | 959 | { |
5064975e | 960 | struct vfsmount *upper_mnt; |
6ee8acf0 MS |
961 | int err; |
962 | ||
ad204488 | 963 | err = ovl_mount_dir(ofs->config.upperdir, upperpath); |
6ee8acf0 MS |
964 | if (err) |
965 | goto out; | |
966 | ||
967 | /* Upper fs should not be r/o */ | |
968 | if (sb_rdonly(upperpath->mnt->mnt_sb)) { | |
969 | pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n"); | |
970 | err = -EINVAL; | |
971 | goto out; | |
972 | } | |
973 | ||
ad204488 | 974 | err = ovl_check_namelen(upperpath, ofs, ofs->config.upperdir); |
6ee8acf0 MS |
975 | if (err) |
976 | goto out; | |
977 | ||
978 | err = -EBUSY; | |
979 | if (ovl_inuse_trylock(upperpath->dentry)) { | |
ad204488 MS |
980 | ofs->upperdir_locked = true; |
981 | } else if (ofs->config.index) { | |
6ee8acf0 MS |
982 | pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n"); |
983 | goto out; | |
984 | } else { | |
985 | pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n"); | |
986 | } | |
5064975e MS |
987 | |
988 | upper_mnt = clone_private_mount(upperpath); | |
989 | err = PTR_ERR(upper_mnt); | |
990 | if (IS_ERR(upper_mnt)) { | |
991 | pr_err("overlayfs: failed to clone upperpath\n"); | |
992 | goto out; | |
993 | } | |
994 | ||
995 | /* Don't inherit atime flags */ | |
996 | upper_mnt->mnt_flags &= ~(MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME); | |
ad204488 | 997 | ofs->upper_mnt = upper_mnt; |
6ee8acf0 MS |
998 | err = 0; |
999 | out: | |
1000 | return err; | |
1001 | } | |
1002 | ||
ad204488 | 1003 | static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath) |
8ed61dc3 | 1004 | { |
2ba9d57e | 1005 | struct vfsmount *mnt = ofs->upper_mnt; |
8ed61dc3 | 1006 | struct dentry *temp; |
e487d889 | 1007 | int fh_type; |
8ed61dc3 MS |
1008 | int err; |
1009 | ||
2ba9d57e AG |
1010 | err = mnt_want_write(mnt); |
1011 | if (err) | |
1012 | return err; | |
1013 | ||
ad204488 MS |
1014 | ofs->workdir = ovl_workdir_create(ofs, OVL_WORKDIR_NAME, false); |
1015 | if (!ofs->workdir) | |
2ba9d57e | 1016 | goto out; |
8ed61dc3 MS |
1017 | |
1018 | /* | |
1019 | * Upper should support d_type, else whiteouts are visible. Given | |
1020 | * workdir and upper are on same fs, we can do iterate_dir() on | |
1021 | * workdir. This check requires successful creation of workdir in | |
1022 | * previous step. | |
1023 | */ | |
1024 | err = ovl_check_d_type_supported(workpath); | |
1025 | if (err < 0) | |
2ba9d57e | 1026 | goto out; |
8ed61dc3 MS |
1027 | |
1028 | /* | |
1029 | * We allowed this configuration and don't want to break users over | |
1030 | * kernel upgrade. So warn instead of erroring out. | |
1031 | */ | |
1032 | if (!err) | |
1033 | pr_warn("overlayfs: upper fs needs to support d_type.\n"); | |
1034 | ||
1035 | /* Check if upper/work fs supports O_TMPFILE */ | |
ad204488 MS |
1036 | temp = ovl_do_tmpfile(ofs->workdir, S_IFREG | 0); |
1037 | ofs->tmpfile = !IS_ERR(temp); | |
1038 | if (ofs->tmpfile) | |
8ed61dc3 MS |
1039 | dput(temp); |
1040 | else | |
1041 | pr_warn("overlayfs: upper fs does not support tmpfile.\n"); | |
1042 | ||
1043 | /* | |
1044 | * Check if upper/work fs supports trusted.overlay.* xattr | |
1045 | */ | |
ad204488 | 1046 | err = ovl_do_setxattr(ofs->workdir, OVL_XATTR_OPAQUE, "0", 1, 0); |
8ed61dc3 | 1047 | if (err) { |
ad204488 | 1048 | ofs->noxattr = true; |
a683737b | 1049 | ofs->config.index = false; |
d5791044 VG |
1050 | ofs->config.metacopy = false; |
1051 | pr_warn("overlayfs: upper fs does not support xattr, falling back to index=off and metacopy=off.\n"); | |
2ba9d57e | 1052 | err = 0; |
8ed61dc3 | 1053 | } else { |
ad204488 | 1054 | vfs_removexattr(ofs->workdir, OVL_XATTR_OPAQUE); |
8ed61dc3 MS |
1055 | } |
1056 | ||
1057 | /* Check if upper/work fs supports file handles */ | |
e487d889 AG |
1058 | fh_type = ovl_can_decode_fh(ofs->workdir->d_sb); |
1059 | if (ofs->config.index && !fh_type) { | |
ad204488 | 1060 | ofs->config.index = false; |
8ed61dc3 MS |
1061 | pr_warn("overlayfs: upper fs does not support file handles, falling back to index=off.\n"); |
1062 | } | |
1063 | ||
e487d889 AG |
1064 | /* Check if upper fs has 32bit inode numbers */ |
1065 | if (fh_type != FILEID_INO32_GEN) | |
1066 | ofs->xino_bits = 0; | |
1067 | ||
f168f109 AG |
1068 | /* NFS export of r/w mount depends on index */ |
1069 | if (ofs->config.nfs_export && !ofs->config.index) { | |
1070 | pr_warn("overlayfs: NFS export requires \"index=on\", falling back to nfs_export=off.\n"); | |
1071 | ofs->config.nfs_export = false; | |
1072 | } | |
2ba9d57e AG |
1073 | out: |
1074 | mnt_drop_write(mnt); | |
1075 | return err; | |
8ed61dc3 MS |
1076 | } |
1077 | ||
ad204488 | 1078 | static int ovl_get_workdir(struct ovl_fs *ofs, struct path *upperpath) |
520d7c86 MS |
1079 | { |
1080 | int err; | |
bca44b52 | 1081 | struct path workpath = { }; |
520d7c86 | 1082 | |
ad204488 | 1083 | err = ovl_mount_dir(ofs->config.workdir, &workpath); |
520d7c86 MS |
1084 | if (err) |
1085 | goto out; | |
1086 | ||
1087 | err = -EINVAL; | |
bca44b52 | 1088 | if (upperpath->mnt != workpath.mnt) { |
520d7c86 MS |
1089 | pr_err("overlayfs: workdir and upperdir must reside under the same mount\n"); |
1090 | goto out; | |
1091 | } | |
bca44b52 | 1092 | if (!ovl_workdir_ok(workpath.dentry, upperpath->dentry)) { |
520d7c86 MS |
1093 | pr_err("overlayfs: workdir and upperdir must be separate subtrees\n"); |
1094 | goto out; | |
1095 | } | |
1096 | ||
1097 | err = -EBUSY; | |
bca44b52 | 1098 | if (ovl_inuse_trylock(workpath.dentry)) { |
ad204488 MS |
1099 | ofs->workdir_locked = true; |
1100 | } else if (ofs->config.index) { | |
520d7c86 MS |
1101 | pr_err("overlayfs: workdir is in-use by another mount, mount with '-o index=off' to override exclusive workdir protection.\n"); |
1102 | goto out; | |
1103 | } else { | |
1104 | pr_warn("overlayfs: workdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n"); | |
1105 | } | |
1106 | ||
ad204488 MS |
1107 | ofs->workbasedir = dget(workpath.dentry); |
1108 | err = ovl_make_workdir(ofs, &workpath); | |
bca44b52 MS |
1109 | if (err) |
1110 | goto out; | |
1111 | ||
520d7c86 MS |
1112 | err = 0; |
1113 | out: | |
bca44b52 MS |
1114 | path_put(&workpath); |
1115 | ||
520d7c86 MS |
1116 | return err; |
1117 | } | |
1118 | ||
ad204488 | 1119 | static int ovl_get_indexdir(struct ovl_fs *ofs, struct ovl_entry *oe, |
95e6d417 | 1120 | struct path *upperpath) |
f7e3a7d9 | 1121 | { |
2ba9d57e | 1122 | struct vfsmount *mnt = ofs->upper_mnt; |
f7e3a7d9 MS |
1123 | int err; |
1124 | ||
2ba9d57e AG |
1125 | err = mnt_want_write(mnt); |
1126 | if (err) | |
1127 | return err; | |
1128 | ||
f7e3a7d9 | 1129 | /* Verify lower root is upper root origin */ |
d9768076 | 1130 | err = ovl_verify_origin(upperpath->dentry, oe->lowerstack[0].dentry, |
05122443 | 1131 | true); |
f7e3a7d9 MS |
1132 | if (err) { |
1133 | pr_err("overlayfs: failed to verify upper root origin\n"); | |
1134 | goto out; | |
1135 | } | |
1136 | ||
ad204488 MS |
1137 | ofs->indexdir = ovl_workdir_create(ofs, OVL_INDEXDIR_NAME, true); |
1138 | if (ofs->indexdir) { | |
ad1d615c AG |
1139 | /* |
1140 | * Verify upper root is exclusively associated with index dir. | |
1141 | * Older kernels stored upper fh in "trusted.overlay.origin" | |
1142 | * xattr. If that xattr exists, verify that it is a match to | |
1143 | * upper dir file handle. In any case, verify or set xattr | |
1144 | * "trusted.overlay.upper" to indicate that index may have | |
1145 | * directory entries. | |
1146 | */ | |
1147 | if (ovl_check_origin_xattr(ofs->indexdir)) { | |
1148 | err = ovl_verify_set_fh(ofs->indexdir, OVL_XATTR_ORIGIN, | |
1149 | upperpath->dentry, true, false); | |
1150 | if (err) | |
1151 | pr_err("overlayfs: failed to verify index dir 'origin' xattr\n"); | |
1152 | } | |
1153 | err = ovl_verify_upper(ofs->indexdir, upperpath->dentry, true); | |
f7e3a7d9 | 1154 | if (err) |
ad1d615c | 1155 | pr_err("overlayfs: failed to verify index dir 'upper' xattr\n"); |
f7e3a7d9 MS |
1156 | |
1157 | /* Cleanup bad/stale/orphan index entries */ | |
1158 | if (!err) | |
1eff1a1d | 1159 | err = ovl_indexdir_cleanup(ofs); |
f7e3a7d9 | 1160 | } |
ad204488 | 1161 | if (err || !ofs->indexdir) |
f7e3a7d9 MS |
1162 | pr_warn("overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index.\n"); |
1163 | ||
1164 | out: | |
2ba9d57e | 1165 | mnt_drop_write(mnt); |
f7e3a7d9 MS |
1166 | return err; |
1167 | } | |
1168 | ||
5148626b AG |
1169 | /* Get a unique fsid for the layer */ |
1170 | static int ovl_get_fsid(struct ovl_fs *ofs, struct super_block *sb) | |
1171 | { | |
1172 | unsigned int i; | |
1173 | dev_t dev; | |
1174 | int err; | |
1175 | ||
1176 | /* fsid 0 is reserved for upper fs even with non upper overlay */ | |
1177 | if (ofs->upper_mnt && ofs->upper_mnt->mnt_sb == sb) | |
1178 | return 0; | |
1179 | ||
1180 | for (i = 0; i < ofs->numlowerfs; i++) { | |
1181 | if (ofs->lower_fs[i].sb == sb) | |
1182 | return i + 1; | |
1183 | } | |
1184 | ||
1185 | err = get_anon_bdev(&dev); | |
1186 | if (err) { | |
1187 | pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n"); | |
1188 | return err; | |
1189 | } | |
1190 | ||
1191 | ofs->lower_fs[ofs->numlowerfs].sb = sb; | |
1192 | ofs->lower_fs[ofs->numlowerfs].pseudo_dev = dev; | |
1193 | ofs->numlowerfs++; | |
1194 | ||
1195 | return ofs->numlowerfs; | |
1196 | } | |
1197 | ||
ad204488 | 1198 | static int ovl_get_lower_layers(struct ovl_fs *ofs, struct path *stack, |
520d7c86 MS |
1199 | unsigned int numlower) |
1200 | { | |
1201 | int err; | |
1202 | unsigned int i; | |
1203 | ||
1204 | err = -ENOMEM; | |
ad204488 | 1205 | ofs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer), |
520d7c86 | 1206 | GFP_KERNEL); |
ad204488 | 1207 | if (ofs->lower_layers == NULL) |
520d7c86 | 1208 | goto out; |
5148626b AG |
1209 | |
1210 | ofs->lower_fs = kcalloc(numlower, sizeof(struct ovl_sb), | |
1211 | GFP_KERNEL); | |
1212 | if (ofs->lower_fs == NULL) | |
1213 | goto out; | |
1214 | ||
520d7c86 MS |
1215 | for (i = 0; i < numlower; i++) { |
1216 | struct vfsmount *mnt; | |
5148626b | 1217 | int fsid; |
520d7c86 | 1218 | |
5148626b AG |
1219 | err = fsid = ovl_get_fsid(ofs, stack[i].mnt->mnt_sb); |
1220 | if (err < 0) | |
520d7c86 | 1221 | goto out; |
520d7c86 MS |
1222 | |
1223 | mnt = clone_private_mount(&stack[i]); | |
1224 | err = PTR_ERR(mnt); | |
1225 | if (IS_ERR(mnt)) { | |
1226 | pr_err("overlayfs: failed to clone lowerpath\n"); | |
520d7c86 MS |
1227 | goto out; |
1228 | } | |
5148626b | 1229 | |
520d7c86 MS |
1230 | /* |
1231 | * Make lower layers R/O. That way fchmod/fchown on lower file | |
1232 | * will fail instead of modifying lower fs. | |
1233 | */ | |
1234 | mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME; | |
1235 | ||
ad204488 | 1236 | ofs->lower_layers[ofs->numlower].mnt = mnt; |
d583ed7d | 1237 | ofs->lower_layers[ofs->numlower].idx = i + 1; |
5148626b AG |
1238 | ofs->lower_layers[ofs->numlower].fsid = fsid; |
1239 | if (fsid) { | |
1240 | ofs->lower_layers[ofs->numlower].fs = | |
1241 | &ofs->lower_fs[fsid - 1]; | |
1242 | } | |
ad204488 | 1243 | ofs->numlower++; |
520d7c86 | 1244 | } |
e487d889 | 1245 | |
795939a9 AG |
1246 | /* |
1247 | * When all layers on same fs, overlay can use real inode numbers. | |
1248 | * With mount option "xino=on", mounter declares that there are enough | |
1249 | * free high bits in underlying fs to hold the unique fsid. | |
1250 | * If overlayfs does encounter underlying inodes using the high xino | |
1251 | * bits reserved for fsid, it emits a warning and uses the original | |
1252 | * inode number. | |
1253 | */ | |
1254 | if (!ofs->numlowerfs || (ofs->numlowerfs == 1 && !ofs->upper_mnt)) { | |
e487d889 | 1255 | ofs->xino_bits = 0; |
795939a9 AG |
1256 | ofs->config.xino = OVL_XINO_OFF; |
1257 | } else if (ofs->config.xino == OVL_XINO_ON && !ofs->xino_bits) { | |
1258 | /* | |
1259 | * This is a roundup of number of bits needed for numlowerfs+1 | |
1260 | * (i.e. ilog2(numlowerfs+1 - 1) + 1). fsid 0 is reserved for | |
1261 | * upper fs even with non upper overlay. | |
1262 | */ | |
1263 | BUILD_BUG_ON(ilog2(OVL_MAX_STACK) > 31); | |
1264 | ofs->xino_bits = ilog2(ofs->numlowerfs) + 1; | |
1265 | } | |
1266 | ||
1267 | if (ofs->xino_bits) { | |
1268 | pr_info("overlayfs: \"xino\" feature enabled using %d upper inode bits.\n", | |
1269 | ofs->xino_bits); | |
1270 | } | |
e487d889 | 1271 | |
520d7c86 MS |
1272 | err = 0; |
1273 | out: | |
1274 | return err; | |
1275 | } | |
1276 | ||
4155c10a | 1277 | static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, |
ad204488 | 1278 | struct ovl_fs *ofs) |
53dbb0b4 MS |
1279 | { |
1280 | int err; | |
1281 | char *lowertmp, *lower; | |
4155c10a MS |
1282 | struct path *stack = NULL; |
1283 | unsigned int stacklen, numlower = 0, i; | |
53dbb0b4 | 1284 | bool remote = false; |
4155c10a | 1285 | struct ovl_entry *oe; |
53dbb0b4 MS |
1286 | |
1287 | err = -ENOMEM; | |
ad204488 | 1288 | lowertmp = kstrdup(ofs->config.lowerdir, GFP_KERNEL); |
53dbb0b4 | 1289 | if (!lowertmp) |
4155c10a | 1290 | goto out_err; |
53dbb0b4 MS |
1291 | |
1292 | err = -EINVAL; | |
1293 | stacklen = ovl_split_lowerdirs(lowertmp); | |
1294 | if (stacklen > OVL_MAX_STACK) { | |
1295 | pr_err("overlayfs: too many lower directories, limit is %d\n", | |
1296 | OVL_MAX_STACK); | |
4155c10a | 1297 | goto out_err; |
ad204488 | 1298 | } else if (!ofs->config.upperdir && stacklen == 1) { |
53dbb0b4 | 1299 | pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n"); |
4155c10a | 1300 | goto out_err; |
f168f109 AG |
1301 | } else if (!ofs->config.upperdir && ofs->config.nfs_export && |
1302 | ofs->config.redirect_follow) { | |
1303 | pr_warn("overlayfs: NFS export requires \"redirect_dir=nofollow\" on non-upper mount, falling back to nfs_export=off.\n"); | |
1304 | ofs->config.nfs_export = false; | |
53dbb0b4 MS |
1305 | } |
1306 | ||
1307 | err = -ENOMEM; | |
1308 | stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL); | |
1309 | if (!stack) | |
4155c10a | 1310 | goto out_err; |
53dbb0b4 MS |
1311 | |
1312 | err = -EINVAL; | |
1313 | lower = lowertmp; | |
1314 | for (numlower = 0; numlower < stacklen; numlower++) { | |
ad204488 | 1315 | err = ovl_lower_dir(lower, &stack[numlower], ofs, |
53dbb0b4 MS |
1316 | &sb->s_stack_depth, &remote); |
1317 | if (err) | |
4155c10a | 1318 | goto out_err; |
53dbb0b4 MS |
1319 | |
1320 | lower = strchr(lower, '\0') + 1; | |
1321 | } | |
1322 | ||
1323 | err = -EINVAL; | |
1324 | sb->s_stack_depth++; | |
1325 | if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { | |
1326 | pr_err("overlayfs: maximum fs stacking depth exceeded\n"); | |
4155c10a | 1327 | goto out_err; |
53dbb0b4 MS |
1328 | } |
1329 | ||
ad204488 | 1330 | err = ovl_get_lower_layers(ofs, stack, numlower); |
4155c10a MS |
1331 | if (err) |
1332 | goto out_err; | |
1333 | ||
1334 | err = -ENOMEM; | |
1335 | oe = ovl_alloc_entry(numlower); | |
1336 | if (!oe) | |
1337 | goto out_err; | |
1338 | ||
1339 | for (i = 0; i < numlower; i++) { | |
1340 | oe->lowerstack[i].dentry = dget(stack[i].dentry); | |
ad204488 | 1341 | oe->lowerstack[i].layer = &ofs->lower_layers[i]; |
4155c10a | 1342 | } |
53dbb0b4 MS |
1343 | |
1344 | if (remote) | |
1345 | sb->s_d_op = &ovl_reval_dentry_operations; | |
1346 | else | |
1347 | sb->s_d_op = &ovl_dentry_operations; | |
1348 | ||
53dbb0b4 | 1349 | out: |
53dbb0b4 MS |
1350 | for (i = 0; i < numlower; i++) |
1351 | path_put(&stack[i]); | |
1352 | kfree(stack); | |
4155c10a MS |
1353 | kfree(lowertmp); |
1354 | ||
1355 | return oe; | |
1356 | ||
1357 | out_err: | |
1358 | oe = ERR_PTR(err); | |
53dbb0b4 MS |
1359 | goto out; |
1360 | } | |
1361 | ||
e9be9d5e MS |
1362 | static int ovl_fill_super(struct super_block *sb, void *data, int silent) |
1363 | { | |
33006cdf | 1364 | struct path upperpath = { }; |
e9be9d5e | 1365 | struct dentry *root_dentry; |
4155c10a | 1366 | struct ovl_entry *oe; |
ad204488 | 1367 | struct ovl_fs *ofs; |
51f8f3c4 | 1368 | struct cred *cred; |
e9be9d5e MS |
1369 | int err; |
1370 | ||
f45827e8 | 1371 | err = -ENOMEM; |
ad204488 MS |
1372 | ofs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL); |
1373 | if (!ofs) | |
e9be9d5e MS |
1374 | goto out; |
1375 | ||
ad204488 | 1376 | ofs->creator_cred = cred = prepare_creds(); |
c6fe6254 MS |
1377 | if (!cred) |
1378 | goto out_err; | |
1379 | ||
ad204488 | 1380 | ofs->config.index = ovl_index_def; |
f168f109 | 1381 | ofs->config.nfs_export = ovl_nfs_export_def; |
795939a9 | 1382 | ofs->config.xino = ovl_xino_def(); |
d5791044 | 1383 | ofs->config.metacopy = ovl_metacopy_def; |
ad204488 | 1384 | err = ovl_parse_opt((char *) data, &ofs->config); |
f45827e8 | 1385 | if (err) |
a9075cdb | 1386 | goto out_err; |
f45827e8 | 1387 | |
e9be9d5e | 1388 | err = -EINVAL; |
ad204488 | 1389 | if (!ofs->config.lowerdir) { |
07f2af7b KK |
1390 | if (!silent) |
1391 | pr_err("overlayfs: missing 'lowerdir'\n"); | |
a9075cdb | 1392 | goto out_err; |
e9be9d5e MS |
1393 | } |
1394 | ||
53a08cb9 | 1395 | sb->s_stack_depth = 0; |
cf9a6784 | 1396 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
e487d889 | 1397 | /* Assume underlaying fs uses 32bit inodes unless proven otherwise */ |
795939a9 AG |
1398 | if (ofs->config.xino != OVL_XINO_OFF) |
1399 | ofs->xino_bits = BITS_PER_LONG - 32; | |
1400 | ||
ad204488 MS |
1401 | if (ofs->config.upperdir) { |
1402 | if (!ofs->config.workdir) { | |
53a08cb9 | 1403 | pr_err("overlayfs: missing 'workdir'\n"); |
a9075cdb | 1404 | goto out_err; |
53a08cb9 | 1405 | } |
e9be9d5e | 1406 | |
ad204488 | 1407 | err = ovl_get_upper(ofs, &upperpath); |
53a08cb9 | 1408 | if (err) |
a9075cdb | 1409 | goto out_err; |
2cac0c00 | 1410 | |
ad204488 | 1411 | err = ovl_get_workdir(ofs, &upperpath); |
8ed61dc3 | 1412 | if (err) |
a9075cdb | 1413 | goto out_err; |
c6fe6254 | 1414 | |
ad204488 | 1415 | if (!ofs->workdir) |
1751e8a6 | 1416 | sb->s_flags |= SB_RDONLY; |
6e88256e | 1417 | |
ad204488 MS |
1418 | sb->s_stack_depth = ofs->upper_mnt->mnt_sb->s_stack_depth; |
1419 | sb->s_time_gran = ofs->upper_mnt->mnt_sb->s_time_gran; | |
c6fe6254 | 1420 | |
e9be9d5e | 1421 | } |
ad204488 | 1422 | oe = ovl_get_lowerstack(sb, ofs); |
4155c10a MS |
1423 | err = PTR_ERR(oe); |
1424 | if (IS_ERR(oe)) | |
a9075cdb | 1425 | goto out_err; |
e9be9d5e | 1426 | |
71cbad7e | 1427 | /* If the upper fs is nonexistent, we mark overlayfs r/o too */ |
ad204488 | 1428 | if (!ofs->upper_mnt) |
1751e8a6 | 1429 | sb->s_flags |= SB_RDONLY; |
e9be9d5e | 1430 | |
ad204488 MS |
1431 | if (!(ovl_force_readonly(ofs)) && ofs->config.index) { |
1432 | err = ovl_get_indexdir(ofs, oe, &upperpath); | |
54fb347e | 1433 | if (err) |
4155c10a | 1434 | goto out_free_oe; |
6e88256e | 1435 | |
972d0093 AG |
1436 | /* Force r/o mount with no index dir */ |
1437 | if (!ofs->indexdir) { | |
1438 | dput(ofs->workdir); | |
1439 | ofs->workdir = NULL; | |
1751e8a6 | 1440 | sb->s_flags |= SB_RDONLY; |
972d0093 AG |
1441 | } |
1442 | ||
02bcd157 AG |
1443 | } |
1444 | ||
972d0093 | 1445 | /* Show index=off in /proc/mounts for forced r/o mount */ |
f168f109 | 1446 | if (!ofs->indexdir) { |
ad204488 | 1447 | ofs->config.index = false; |
f168f109 AG |
1448 | if (ofs->upper_mnt && ofs->config.nfs_export) { |
1449 | pr_warn("overlayfs: NFS export requires an index dir, falling back to nfs_export=off.\n"); | |
1450 | ofs->config.nfs_export = false; | |
1451 | } | |
1452 | } | |
02bcd157 | 1453 | |
d5791044 VG |
1454 | if (ofs->config.metacopy && ofs->config.nfs_export) { |
1455 | pr_warn("overlayfs: NFS export is not supported with metadata only copy up, falling back to nfs_export=off.\n"); | |
1456 | ofs->config.nfs_export = false; | |
1457 | } | |
1458 | ||
8383f174 AG |
1459 | if (ofs->config.nfs_export) |
1460 | sb->s_export_op = &ovl_export_operations; | |
1461 | ||
51f8f3c4 KK |
1462 | /* Never override disk quota limits or use reserved space */ |
1463 | cap_lower(cred->cap_effective, CAP_SYS_RESOURCE); | |
1464 | ||
655042cc VG |
1465 | sb->s_magic = OVERLAYFS_SUPER_MAGIC; |
1466 | sb->s_op = &ovl_super_operations; | |
1467 | sb->s_xattr = ovl_xattr_handlers; | |
ad204488 | 1468 | sb->s_fs_info = ofs; |
de2a4a50 | 1469 | sb->s_flags |= SB_POSIXACL; |
655042cc | 1470 | |
c6fe6254 | 1471 | err = -ENOMEM; |
ca4c8a3a | 1472 | root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, 0)); |
e9be9d5e | 1473 | if (!root_dentry) |
4155c10a | 1474 | goto out_free_oe; |
e9be9d5e | 1475 | |
c62520a8 AG |
1476 | root_dentry->d_fsdata = oe; |
1477 | ||
e9be9d5e | 1478 | mntput(upperpath.mnt); |
f3a15685 | 1479 | if (upperpath.dentry) { |
c62520a8 | 1480 | ovl_dentry_set_upper_alias(root_dentry); |
13c72075 MS |
1481 | if (ovl_is_impuredir(upperpath.dentry)) |
1482 | ovl_set_flag(OVL_IMPURE, d_inode(root_dentry)); | |
f3a15685 | 1483 | } |
e9be9d5e | 1484 | |
b79e05aa AG |
1485 | /* Root is always merge -> can have whiteouts */ |
1486 | ovl_set_flag(OVL_WHITEOUTS, d_inode(root_dentry)); | |
2ca3c148 | 1487 | ovl_dentry_set_flag(OVL_E_CONNECTED, root_dentry); |
0c288874 | 1488 | ovl_set_upperdata(d_inode(root_dentry)); |
09d8b586 MS |
1489 | ovl_inode_init(d_inode(root_dentry), upperpath.dentry, |
1490 | ovl_dentry_lower(root_dentry)); | |
ed06e069 | 1491 | |
e9be9d5e | 1492 | sb->s_root = root_dentry; |
e9be9d5e MS |
1493 | |
1494 | return 0; | |
1495 | ||
4155c10a MS |
1496 | out_free_oe: |
1497 | ovl_entry_stack_free(oe); | |
b9343632 | 1498 | kfree(oe); |
4155c10a | 1499 | out_err: |
e9be9d5e | 1500 | path_put(&upperpath); |
ad204488 | 1501 | ovl_free_fs(ofs); |
e9be9d5e MS |
1502 | out: |
1503 | return err; | |
1504 | } | |
1505 | ||
1506 | static struct dentry *ovl_mount(struct file_system_type *fs_type, int flags, | |
1507 | const char *dev_name, void *raw_data) | |
1508 | { | |
1509 | return mount_nodev(fs_type, flags, raw_data, ovl_fill_super); | |
1510 | } | |
1511 | ||
1512 | static struct file_system_type ovl_fs_type = { | |
1513 | .owner = THIS_MODULE, | |
ef94b186 | 1514 | .name = "overlay", |
e9be9d5e MS |
1515 | .mount = ovl_mount, |
1516 | .kill_sb = kill_anon_super, | |
1517 | }; | |
ef94b186 | 1518 | MODULE_ALIAS_FS("overlay"); |
e9be9d5e | 1519 | |
13cf199d AG |
1520 | static void ovl_inode_init_once(void *foo) |
1521 | { | |
1522 | struct ovl_inode *oi = foo; | |
1523 | ||
1524 | inode_init_once(&oi->vfs_inode); | |
1525 | } | |
1526 | ||
e9be9d5e MS |
1527 | static int __init ovl_init(void) |
1528 | { | |
13cf199d AG |
1529 | int err; |
1530 | ||
1531 | ovl_inode_cachep = kmem_cache_create("ovl_inode", | |
1532 | sizeof(struct ovl_inode), 0, | |
1533 | (SLAB_RECLAIM_ACCOUNT| | |
1534 | SLAB_MEM_SPREAD|SLAB_ACCOUNT), | |
1535 | ovl_inode_init_once); | |
1536 | if (ovl_inode_cachep == NULL) | |
1537 | return -ENOMEM; | |
1538 | ||
1539 | err = register_filesystem(&ovl_fs_type); | |
1540 | if (err) | |
1541 | kmem_cache_destroy(ovl_inode_cachep); | |
1542 | ||
1543 | return err; | |
e9be9d5e MS |
1544 | } |
1545 | ||
1546 | static void __exit ovl_exit(void) | |
1547 | { | |
1548 | unregister_filesystem(&ovl_fs_type); | |
13cf199d AG |
1549 | |
1550 | /* | |
1551 | * Make sure all delayed rcu free inodes are flushed before we | |
1552 | * destroy cache. | |
1553 | */ | |
1554 | rcu_barrier(); | |
1555 | kmem_cache_destroy(ovl_inode_cachep); | |
1556 | ||
e9be9d5e MS |
1557 | } |
1558 | ||
1559 | module_init(ovl_init); | |
1560 | module_exit(ovl_exit); |