1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
2 | /* |
3 | * |
4 | * Copyright (C) 2011 Novell Inc. |
5 | */ |
6 | |
7 | #include <linux/kernel.h> |
8 | #include <linux/uuid.h> |
9 | #include <linux/fs.h> |
10 | #include <linux/fsverity.h> |
11 | #include <linux/namei.h> |
12 | #include <linux/posix_acl.h> |
13 | #include <linux/posix_acl_xattr.h> |
14 | #include "ovl_entry.h" |
15 | |
16 | #undef pr_fmt |
17 | #define pr_fmt(fmt) "overlayfs: " fmt |
18 | |
19 | enum ovl_path_type { |
20 | __OVL_PATH_UPPER = (1 << 0), |
21 | __OVL_PATH_MERGE = (1 << 1), |
22 | __OVL_PATH_ORIGIN = (1 << 2), |
23 | }; |
24 | |
25 | #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER) |
26 | #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE) |
27 | #define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN) |
28 | |
29 | #define OVL_XATTR_NAMESPACE "overlay." |
30 | #define OVL_XATTR_TRUSTED_PREFIX XATTR_TRUSTED_PREFIX OVL_XATTR_NAMESPACE |
31 | #define OVL_XATTR_TRUSTED_PREFIX_LEN (sizeof(OVL_XATTR_TRUSTED_PREFIX) - 1) |
32 | #define OVL_XATTR_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE |
33 | #define OVL_XATTR_USER_PREFIX_LEN (sizeof(OVL_XATTR_USER_PREFIX) - 1) |
34 | |
35 | #define OVL_XATTR_ESCAPE_PREFIX OVL_XATTR_NAMESPACE |
36 | #define OVL_XATTR_ESCAPE_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_PREFIX) - 1) |
37 | #define OVL_XATTR_ESCAPE_TRUSTED_PREFIX OVL_XATTR_TRUSTED_PREFIX OVL_XATTR_ESCAPE_PREFIX |
38 | #define OVL_XATTR_ESCAPE_TRUSTED_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_TRUSTED_PREFIX) - 1) |
39 | #define OVL_XATTR_ESCAPE_USER_PREFIX OVL_XATTR_USER_PREFIX OVL_XATTR_ESCAPE_PREFIX |
40 | #define OVL_XATTR_ESCAPE_USER_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_USER_PREFIX) - 1) |
41 | |
42 | enum ovl_xattr { |
43 | OVL_XATTR_OPAQUE, |
44 | OVL_XATTR_REDIRECT, |
45 | OVL_XATTR_ORIGIN, |
46 | OVL_XATTR_IMPURE, |
47 | OVL_XATTR_NLINK, |
48 | OVL_XATTR_UPPER, |
49 | OVL_XATTR_UUID, |
50 | OVL_XATTR_METACOPY, |
51 | OVL_XATTR_PROTATTR, |
52 | OVL_XATTR_XWHITEOUT, |
53 | }; |
54 | |
55 | enum ovl_inode_flag { |
56 | /* Pure upper dir that may contain non pure upper entries */ |
57 | OVL_IMPURE, |
58 | /* Non-merge dir that may contain whiteout entries */ |
59 | OVL_WHITEOUTS, |
60 | OVL_INDEX, |
61 | OVL_UPPERDATA, |
62 | /* Inode number will remain constant over copy up. */ |
63 | OVL_CONST_INO, |
64 | OVL_HAS_DIGEST, |
65 | OVL_VERIFIED_DIGEST, |
66 | }; |
67 | |
68 | enum ovl_entry_flag { |
69 | OVL_E_UPPER_ALIAS, |
70 | OVL_E_OPAQUE, |
71 | OVL_E_CONNECTED, |
72 | /* Lower stack may contain xwhiteout entries */ |
73 | OVL_E_XWHITEOUTS, |
74 | }; |
75 | |
76 | enum { |
77 | OVL_REDIRECT_OFF, /* "off" mode is never used. In effect */ |
78 | OVL_REDIRECT_FOLLOW, /* ...it translates to either "follow" */ |
79 | OVL_REDIRECT_NOFOLLOW, /* ...or "nofollow". */ |
80 | OVL_REDIRECT_ON, |
81 | }; |
82 | |
83 | enum { |
84 | OVL_UUID_OFF, |
85 | OVL_UUID_NULL, |
86 | OVL_UUID_AUTO, |
87 | OVL_UUID_ON, |
88 | }; |
89 | |
90 | enum { |
91 | OVL_XINO_OFF, |
92 | OVL_XINO_AUTO, |
93 | OVL_XINO_ON, |
94 | }; |
95 | |
96 | enum { |
97 | OVL_VERITY_OFF, |
98 | OVL_VERITY_ON, |
99 | OVL_VERITY_REQUIRE, |
100 | }; |
101 | |
102 | /* |
103 | * The tuple (fh,uuid) is a universal unique identifier for a copy up origin, |
104 | * where: |
105 | * origin.fh - exported file handle of the lower file |
106 | * origin.uuid - uuid of the lower filesystem |
107 | */ |
108 | #define OVL_FH_VERSION 0 |
109 | #define OVL_FH_MAGIC 0xfb |
110 | |
111 | /* CPU byte order required for fid decoding: */ |
112 | #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0) |
113 | #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1) |
114 | /* Is the real inode encoded in fid an upper inode? */ |
115 | #define OVL_FH_FLAG_PATH_UPPER (1 << 2) |
116 | |
117 | #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \ |
118 | OVL_FH_FLAG_PATH_UPPER) |
119 | |
120 | #if defined(__LITTLE_ENDIAN) |
121 | #define OVL_FH_FLAG_CPU_ENDIAN 0 |
122 | #elif defined(__BIG_ENDIAN) |
123 | #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN |
124 | #else |
125 | #error Endianness not defined |
126 | #endif |
127 | |
128 | /* The type used to be returned by overlay exportfs for misaligned fid */ |
129 | #define OVL_FILEID_V0 0xfb |
130 | /* The type returned by overlay exportfs for 32bit aligned fid */ |
131 | #define OVL_FILEID_V1 0xf8 |
132 | |
133 | /* On-disk format for "origin" file handle */ |
134 | struct ovl_fb { |
135 | u8 version; /* 0 */ |
136 | u8 magic; /* 0xfb */ |
137 | u8 len; /* size of this header + size of fid */ |
138 | u8 flags; /* OVL_FH_FLAG_* */ |
139 | u8 type; /* fid_type of fid */ |
140 | uuid_t uuid; /* uuid of filesystem */ |
141 | u32 fid[]; /* file identifier should be 32bit aligned in-memory */ |
142 | } __packed; |
143 | |
144 | /* In-memory and on-wire format for overlay file handle */ |
145 | struct ovl_fh { |
146 | u8 padding[3]; /* make sure fb.fid is 32bit aligned */ |
147 | union { |
148 | struct ovl_fb fb; |
149 | DECLARE_FLEX_ARRAY(u8, buf); |
150 | }; |
151 | } __packed; |
152 | |
153 | #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb) |
154 | #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len) |
155 | #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \ |
156 | offsetof(struct ovl_fb, fid)) |
157 | |
158 | /* On-disk format for "metacopy" xattr (if non-zero size) */ |
159 | struct ovl_metacopy { |
160 | u8 version; /* 0 */ |
161 | u8 len; /* size of this header + used digest bytes */ |
162 | u8 flags; |
163 | u8 digest_algo; /* FS_VERITY_HASH_ALG_* constant, 0 for no digest */ |
164 | u8 digest[FS_VERITY_MAX_DIGEST_SIZE]; /* Only the used part on disk */ |
165 | } __packed; |
166 | |
167 | #define OVL_METACOPY_MAX_SIZE (sizeof(struct ovl_metacopy)) |
168 | #define OVL_METACOPY_MIN_SIZE (OVL_METACOPY_MAX_SIZE - FS_VERITY_MAX_DIGEST_SIZE) |
169 | #define OVL_METACOPY_INIT { 0, OVL_METACOPY_MIN_SIZE } |
170 | |
171 | static inline int ovl_metadata_digest_size(const struct ovl_metacopy *metacopy) |
172 | { |
173 | if (metacopy->len < OVL_METACOPY_MIN_SIZE) |
174 | return 0; |
175 | return (int)metacopy->len - OVL_METACOPY_MIN_SIZE; |
176 | } |
177 | |
178 | extern const char *const ovl_xattr_table[][2]; |
179 | static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) |
180 | { |
181 | return ovl_xattr_table[ox][ofs->config.userxattr]; |
182 | } |
183 | |
184 | /* |
185 | * When changing ownership of an upper object map the intended ownership |
186 | * according to the upper layer's idmapping. When an upper mount idmaps files |
187 | * that are stored on-disk as owned by id 1001 to id 1000 this means stat on |
188 | * this object will report it as being owned by id 1000 when calling stat via |
189 | * the upper mount. |
190 | * In order to change ownership of an object so stat reports id 1000 when |
191 | * called on an idmapped upper mount the value written to disk - i.e., the |
192 | * value stored in ia_*id - must 1001. The mount mapping helper will thus take |
193 | * care to map 1000 to 1001. |
194 | * The mnt idmapping helpers are nops if the upper layer isn't idmapped. |
195 | */ |
196 | static inline int ovl_do_notify_change(struct ovl_fs *ofs, |
197 | struct dentry *upperdentry, |
198 | struct iattr *attr) |
199 | { |
200 | return notify_change(ovl_upper_mnt_idmap(ofs), upperdentry, attr, NULL); |
201 | } |
202 | |
203 | static inline int ovl_do_rmdir(struct ovl_fs *ofs, |
204 | struct inode *dir, struct dentry *dentry) |
205 | { |
206 | int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry); |
207 | |
208 | pr_debug("rmdir(%pd2) = %i\n" , dentry, err); |
209 | return err; |
210 | } |
211 | |
212 | static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir, |
213 | struct dentry *dentry) |
214 | { |
215 | int err = vfs_unlink(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL); |
216 | |
217 | pr_debug("unlink(%pd2) = %i\n" , dentry, err); |
218 | return err; |
219 | } |
220 | |
221 | static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry, |
222 | struct inode *dir, struct dentry *new_dentry) |
223 | { |
224 | int err = vfs_link(old_dentry, ovl_upper_mnt_idmap(ofs), dir, |
225 | new_dentry, NULL); |
226 | |
227 | pr_debug("link(%pd2, %pd2) = %i\n" , old_dentry, new_dentry, err); |
228 | return err; |
229 | } |
230 | |
231 | static inline int ovl_do_create(struct ovl_fs *ofs, |
232 | struct inode *dir, struct dentry *dentry, |
233 | umode_t mode) |
234 | { |
235 | int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true); |
236 | |
237 | pr_debug("create(%pd2, 0%o) = %i\n" , dentry, mode, err); |
238 | return err; |
239 | } |
240 | |
241 | static inline int ovl_do_mkdir(struct ovl_fs *ofs, |
242 | struct inode *dir, struct dentry *dentry, |
243 | umode_t mode) |
244 | { |
245 | int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode); |
246 | pr_debug("mkdir(%pd2, 0%o) = %i\n" , dentry, mode, err); |
247 | return err; |
248 | } |
249 | |
250 | static inline int ovl_do_mknod(struct ovl_fs *ofs, |
251 | struct inode *dir, struct dentry *dentry, |
252 | umode_t mode, dev_t dev) |
253 | { |
254 | int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev); |
255 | |
256 | pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n" , dentry, mode, dev, err); |
257 | return err; |
258 | } |
259 | |
260 | static inline int ovl_do_symlink(struct ovl_fs *ofs, |
261 | struct inode *dir, struct dentry *dentry, |
262 | const char *oldname) |
263 | { |
264 | int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname); |
265 | |
266 | pr_debug("symlink(\"%s\", %pd2) = %i\n" , oldname, dentry, err); |
267 | return err; |
268 | } |
269 | |
270 | static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, |
271 | void *value, size_t size) |
272 | { |
273 | int err, len; |
274 | |
275 | WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb); |
276 | |
277 | err = vfs_getxattr(mnt_idmap(mnt: path->mnt), path->dentry, |
278 | name, value, size); |
279 | len = (value && err > 0) ? err : 0; |
280 | |
281 | pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n" , |
282 | path->dentry, name, min(len, 48), value, size, err); |
283 | return err; |
284 | } |
285 | |
286 | static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, |
287 | struct dentry *upperdentry, |
288 | enum ovl_xattr ox, void *value, |
289 | size_t size) |
290 | { |
291 | struct path upperpath = { |
292 | .dentry = upperdentry, |
293 | .mnt = ovl_upper_mnt(ofs), |
294 | }; |
295 | |
296 | return ovl_do_getxattr(path: &upperpath, name: ovl_xattr(ofs, ox), value, size); |
297 | } |
298 | |
299 | static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, |
300 | const struct path *path, |
301 | enum ovl_xattr ox, void *value, |
302 | size_t size) |
303 | { |
304 | return ovl_do_getxattr(path, name: ovl_xattr(ofs, ox), value, size); |
305 | } |
306 | |
307 | static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, |
308 | const char *name, const void *value, |
309 | size_t size, int flags) |
310 | { |
311 | int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name, |
312 | value, size, flags); |
313 | |
314 | pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n" , |
315 | dentry, name, min((int)size, 48), value, size, flags, err); |
316 | return err; |
317 | } |
318 | |
319 | static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, |
320 | enum ovl_xattr ox, const void *value, |
321 | size_t size) |
322 | { |
323 | return ovl_do_setxattr(ofs, dentry, name: ovl_xattr(ofs, ox), value, size, flags: 0); |
324 | } |
325 | |
326 | static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, |
327 | const char *name) |
328 | { |
329 | int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name); |
330 | pr_debug("removexattr(%pd2, \"%s\") = %i\n" , dentry, name, err); |
331 | return err; |
332 | } |
333 | |
334 | static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, |
335 | enum ovl_xattr ox) |
336 | { |
337 | return ovl_do_removexattr(ofs, dentry, name: ovl_xattr(ofs, ox)); |
338 | } |
339 | |
340 | static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, |
341 | const char *acl_name, struct posix_acl *acl) |
342 | { |
343 | return vfs_set_acl(idmap: ovl_upper_mnt_idmap(ofs), dentry, acl_name, kacl: acl); |
344 | } |
345 | |
346 | static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, |
347 | const char *acl_name) |
348 | { |
349 | return vfs_remove_acl(idmap: ovl_upper_mnt_idmap(ofs), dentry, acl_name); |
350 | } |
351 | |
352 | static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir, |
353 | struct dentry *olddentry, struct inode *newdir, |
354 | struct dentry *newdentry, unsigned int flags) |
355 | { |
356 | int err; |
357 | struct renamedata rd = { |
358 | .old_mnt_idmap = ovl_upper_mnt_idmap(ofs), |
359 | .old_dir = olddir, |
360 | .old_dentry = olddentry, |
361 | .new_mnt_idmap = ovl_upper_mnt_idmap(ofs), |
362 | .new_dir = newdir, |
363 | .new_dentry = newdentry, |
364 | .flags = flags, |
365 | }; |
366 | |
367 | pr_debug("rename(%pd2, %pd2, 0x%x)\n" , olddentry, newdentry, flags); |
368 | err = vfs_rename(&rd); |
369 | if (err) { |
370 | pr_debug("...rename(%pd2, %pd2, ...) = %i\n" , |
371 | olddentry, newdentry, err); |
372 | } |
373 | return err; |
374 | } |
375 | |
376 | static inline int ovl_do_whiteout(struct ovl_fs *ofs, |
377 | struct inode *dir, struct dentry *dentry) |
378 | { |
379 | int err = vfs_whiteout(idmap: ovl_upper_mnt_idmap(ofs), dir, dentry); |
380 | pr_debug("whiteout(%pd2) = %i\n" , dentry, err); |
381 | return err; |
382 | } |
383 | |
384 | static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, |
385 | struct dentry *dentry, umode_t mode) |
386 | { |
387 | struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; |
388 | struct file *file = kernel_tmpfile_open(idmap: ovl_upper_mnt_idmap(ofs), parentpath: &path, |
389 | mode, O_LARGEFILE | O_WRONLY, |
390 | current_cred()); |
391 | int err = PTR_ERR_OR_ZERO(ptr: file); |
392 | |
393 | pr_debug("tmpfile(%pd2, 0%o) = %i\n" , dentry, mode, err); |
394 | return file; |
395 | } |
396 | |
397 | static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, |
398 | const char *name, |
399 | struct dentry *base, int len) |
400 | { |
401 | return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len); |
402 | } |
403 | |
404 | static inline bool ovl_open_flags_need_copy_up(int flags) |
405 | { |
406 | if (!flags) |
407 | return false; |
408 | |
409 | return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); |
410 | } |
411 | |
412 | static inline int ovl_do_getattr(const struct path *path, struct kstat *stat, |
413 | u32 request_mask, unsigned int flags) |
414 | { |
415 | if (flags & AT_GETATTR_NOSEC) |
416 | return vfs_getattr_nosec(path, stat, request_mask, flags); |
417 | return vfs_getattr(path, stat, request_mask, flags); |
418 | } |
419 | |
420 | /* util.c */ |
421 | int ovl_get_write_access(struct dentry *dentry); |
422 | void ovl_put_write_access(struct dentry *dentry); |
423 | void ovl_start_write(struct dentry *dentry); |
424 | void ovl_end_write(struct dentry *dentry); |
425 | int ovl_want_write(struct dentry *dentry); |
426 | void ovl_drop_write(struct dentry *dentry); |
427 | struct dentry *ovl_workdir(struct dentry *dentry); |
428 | const struct cred *ovl_override_creds(struct super_block *sb); |
429 | |
430 | static inline const struct cred *ovl_creds(struct super_block *sb) |
431 | { |
432 | return OVL_FS(sb)->creator_cred; |
433 | } |
434 | |
435 | int ovl_can_decode_fh(struct super_block *sb); |
436 | struct dentry *ovl_indexdir(struct super_block *sb); |
437 | bool ovl_index_all(struct super_block *sb); |
438 | bool ovl_verify_lower(struct super_block *sb); |
439 | struct ovl_path *ovl_stack_alloc(unsigned int n); |
440 | void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); |
441 | void ovl_stack_put(struct ovl_path *stack, unsigned int n); |
442 | void ovl_stack_free(struct ovl_path *stack, unsigned int n); |
443 | struct ovl_entry *ovl_alloc_entry(unsigned int numlower); |
444 | void ovl_free_entry(struct ovl_entry *oe); |
445 | bool ovl_dentry_remote(struct dentry *dentry); |
446 | void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); |
447 | void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, |
448 | struct ovl_entry *oe); |
449 | void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, |
450 | struct ovl_entry *oe, unsigned int mask); |
451 | bool ovl_dentry_weird(struct dentry *dentry); |
452 | enum ovl_path_type ovl_path_type(struct dentry *dentry); |
453 | void ovl_path_upper(struct dentry *dentry, struct path *path); |
454 | void ovl_path_lower(struct dentry *dentry, struct path *path); |
455 | void ovl_path_lowerdata(struct dentry *dentry, struct path *path); |
456 | struct inode *ovl_i_path_real(struct inode *inode, struct path *path); |
457 | enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); |
458 | enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); |
459 | struct dentry *ovl_dentry_upper(struct dentry *dentry); |
460 | struct dentry *ovl_dentry_lower(struct dentry *dentry); |
461 | struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); |
462 | int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); |
463 | const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); |
464 | const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); |
465 | struct dentry *ovl_dentry_real(struct dentry *dentry); |
466 | struct dentry *ovl_i_dentry_upper(struct inode *inode); |
467 | struct inode *ovl_inode_upper(struct inode *inode); |
468 | struct inode *ovl_inode_lower(struct inode *inode); |
469 | struct inode *ovl_inode_lowerdata(struct inode *inode); |
470 | struct inode *ovl_inode_real(struct inode *inode); |
471 | struct inode *ovl_inode_realdata(struct inode *inode); |
472 | const char *ovl_lowerdata_redirect(struct inode *inode); |
473 | struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); |
474 | void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); |
475 | void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); |
476 | void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); |
477 | bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); |
478 | bool ovl_dentry_is_opaque(struct dentry *dentry); |
479 | bool ovl_dentry_is_whiteout(struct dentry *dentry); |
480 | void ovl_dentry_set_opaque(struct dentry *dentry); |
481 | bool ovl_dentry_has_xwhiteouts(struct dentry *dentry); |
482 | void ovl_dentry_set_xwhiteouts(struct dentry *dentry); |
483 | void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs, |
484 | const struct ovl_layer *layer); |
485 | bool ovl_dentry_has_upper_alias(struct dentry *dentry); |
486 | void ovl_dentry_set_upper_alias(struct dentry *dentry); |
487 | bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); |
488 | bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); |
489 | bool ovl_has_upperdata(struct inode *inode); |
490 | void ovl_set_upperdata(struct inode *inode); |
491 | const char *ovl_dentry_get_redirect(struct dentry *dentry); |
492 | void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); |
493 | void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); |
494 | void ovl_dir_modified(struct dentry *dentry, bool impurity); |
495 | u64 ovl_inode_version_get(struct inode *inode); |
496 | bool ovl_is_whiteout(struct dentry *dentry); |
497 | bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); |
498 | struct file *ovl_path_open(const struct path *path, int flags); |
499 | int ovl_copy_up_start(struct dentry *dentry, int flags); |
500 | void ovl_copy_up_end(struct dentry *dentry); |
501 | bool ovl_already_copied_up(struct dentry *dentry, int flags); |
502 | char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path, |
503 | enum ovl_xattr ox); |
504 | bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); |
505 | bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path); |
506 | bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, |
507 | const struct path *upperpath); |
508 | |
509 | static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs, |
510 | struct dentry *upperdentry) |
511 | { |
512 | struct path upperpath = { |
513 | .dentry = upperdentry, |
514 | .mnt = ovl_upper_mnt(ofs), |
515 | }; |
516 | return ovl_path_is_whiteout(ofs, path: &upperpath); |
517 | } |
518 | |
519 | static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, |
520 | struct dentry *upperdentry) |
521 | { |
522 | struct path upperpath = { |
523 | .dentry = upperdentry, |
524 | .mnt = ovl_upper_mnt(ofs), |
525 | }; |
526 | return ovl_path_check_origin_xattr(ofs, path: &upperpath); |
527 | } |
528 | |
529 | int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, |
530 | enum ovl_xattr ox, const void *value, size_t size, |
531 | int xerr); |
532 | int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); |
533 | bool ovl_inuse_trylock(struct dentry *dentry); |
534 | void ovl_inuse_unlock(struct dentry *dentry); |
535 | bool ovl_is_inuse(struct dentry *dentry); |
536 | bool ovl_need_index(struct dentry *dentry); |
537 | int ovl_nlink_start(struct dentry *dentry); |
538 | void ovl_nlink_end(struct dentry *dentry); |
539 | int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); |
540 | int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path, |
541 | struct ovl_metacopy *data); |
542 | int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d, |
543 | struct ovl_metacopy *metacopy); |
544 | bool ovl_is_metacopy_dentry(struct dentry *dentry); |
545 | char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); |
546 | int ovl_ensure_verity_loaded(struct path *path); |
547 | int ovl_get_verity_xattr(struct ovl_fs *ofs, const struct path *path, |
548 | u8 *digest_buf, int *buf_length); |
549 | int ovl_validate_verity(struct ovl_fs *ofs, |
550 | struct path *metapath, |
551 | struct path *datapath); |
552 | int ovl_get_verity_digest(struct ovl_fs *ofs, struct path *src, |
553 | struct ovl_metacopy *metacopy); |
554 | int ovl_sync_status(struct ovl_fs *ofs); |
555 | |
556 | static inline void ovl_set_flag(unsigned long flag, struct inode *inode) |
557 | { |
558 | set_bit(nr: flag, addr: &OVL_I(inode)->flags); |
559 | } |
560 | |
561 | static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) |
562 | { |
563 | clear_bit(nr: flag, addr: &OVL_I(inode)->flags); |
564 | } |
565 | |
566 | static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) |
567 | { |
568 | return test_bit(flag, &OVL_I(inode)->flags); |
569 | } |
570 | |
571 | static inline bool ovl_is_impuredir(struct super_block *sb, |
572 | struct dentry *upperdentry) |
573 | { |
574 | struct ovl_fs *ofs = OVL_FS(sb); |
575 | struct path upperpath = { |
576 | .dentry = upperdentry, |
577 | .mnt = ovl_upper_mnt(ofs), |
578 | }; |
579 | |
580 | return ovl_get_dir_xattr_val(ofs, path: &upperpath, ox: OVL_XATTR_IMPURE) == 'y'; |
581 | } |
582 | |
583 | static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs, |
584 | const struct path *path) |
585 | { |
586 | return ovl_get_dir_xattr_val(ofs, path, ox: OVL_XATTR_OPAQUE); |
587 | } |
588 | |
589 | static inline bool ovl_redirect_follow(struct ovl_fs *ofs) |
590 | { |
591 | return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW; |
592 | } |
593 | |
594 | static inline bool ovl_redirect_dir(struct ovl_fs *ofs) |
595 | { |
596 | return ofs->config.redirect_mode == OVL_REDIRECT_ON; |
597 | } |
598 | |
599 | static inline bool ovl_origin_uuid(struct ovl_fs *ofs) |
600 | { |
601 | return ofs->config.uuid != OVL_UUID_OFF; |
602 | } |
603 | |
604 | static inline bool ovl_has_fsid(struct ovl_fs *ofs) |
605 | { |
606 | return ofs->config.uuid == OVL_UUID_ON || |
607 | ofs->config.uuid == OVL_UUID_AUTO; |
608 | } |
609 | |
610 | /* |
611 | * With xino=auto, we do best effort to keep all inodes on same st_dev and |
612 | * d_ino consistent with st_ino. |
613 | * With xino=on, we do the same effort but we warn if we failed. |
614 | */ |
615 | static inline bool ovl_xino_warn(struct ovl_fs *ofs) |
616 | { |
617 | return ofs->config.xino == OVL_XINO_ON; |
618 | } |
619 | |
620 | /* |
621 | * To avoid regressions in existing setups with overlay lower offline changes, |
622 | * we allow lower changes only if none of the new features are used. |
623 | */ |
624 | static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) |
625 | { |
626 | return (!ofs->config.index && !ofs->config.metacopy && |
627 | !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs)); |
628 | } |
629 | |
630 | /* All layers on same fs? */ |
631 | static inline bool ovl_same_fs(struct ovl_fs *ofs) |
632 | { |
633 | return ofs->xino_mode == 0; |
634 | } |
635 | |
636 | /* All overlay inodes have same st_dev? */ |
637 | static inline bool ovl_same_dev(struct ovl_fs *ofs) |
638 | { |
639 | return ofs->xino_mode >= 0; |
640 | } |
641 | |
642 | static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) |
643 | { |
644 | return ovl_same_dev(ofs) ? ofs->xino_mode : 0; |
645 | } |
646 | |
647 | static inline void ovl_inode_lock(struct inode *inode) |
648 | { |
649 | mutex_lock(&OVL_I(inode)->lock); |
650 | } |
651 | |
652 | static inline int ovl_inode_lock_interruptible(struct inode *inode) |
653 | { |
654 | return mutex_lock_interruptible(&OVL_I(inode)->lock); |
655 | } |
656 | |
657 | static inline void ovl_inode_unlock(struct inode *inode) |
658 | { |
659 | mutex_unlock(lock: &OVL_I(inode)->lock); |
660 | } |
661 | |
662 | |
663 | /* namei.c */ |
664 | int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); |
665 | |
666 | static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) |
667 | { |
668 | if (fh_len < sizeof(struct ovl_fh)) |
669 | return -EINVAL; |
670 | |
671 | return ovl_check_fb_len(fb: &fh->fb, fb_len: fh_len - OVL_FH_WIRE_OFFSET); |
672 | } |
673 | |
674 | struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, |
675 | struct vfsmount *mnt, bool connected); |
676 | int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, |
677 | struct dentry *upperdentry, struct ovl_path **stackp); |
678 | int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, |
679 | enum ovl_xattr ox, const struct ovl_fh *fh, |
680 | bool is_upper, bool set); |
681 | int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry, |
682 | enum ovl_xattr ox, struct dentry *real, |
683 | bool is_upper, bool set); |
684 | struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, |
685 | bool connected); |
686 | int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); |
687 | int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name); |
688 | int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, |
689 | struct qstr *name); |
690 | struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); |
691 | struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, |
692 | struct dentry *origin, bool verify); |
693 | int ovl_path_next(int idx, struct dentry *dentry, struct path *path, |
694 | const struct ovl_layer **layer); |
695 | int ovl_verify_lowerdata(struct dentry *dentry); |
696 | struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, |
697 | unsigned int flags); |
698 | bool ovl_lower_positive(struct dentry *dentry); |
699 | |
700 | static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper, |
701 | const struct ovl_fh *fh, bool set) |
702 | { |
703 | return ovl_verify_set_fh(ofs, dentry: upper, ox: OVL_XATTR_ORIGIN, fh, is_upper: false, set); |
704 | } |
705 | |
706 | static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, |
707 | struct dentry *origin, bool set) |
708 | { |
709 | return ovl_verify_origin_xattr(ofs, dentry: upper, ox: OVL_XATTR_ORIGIN, real: origin, |
710 | is_upper: false, set); |
711 | } |
712 | |
713 | static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, |
714 | struct dentry *upper, bool set) |
715 | { |
716 | return ovl_verify_origin_xattr(ofs, dentry: index, ox: OVL_XATTR_UPPER, real: upper, |
717 | is_upper: true, set); |
718 | } |
719 | |
720 | /* readdir.c */ |
721 | extern const struct file_operations ovl_dir_operations; |
722 | struct file *ovl_dir_real_file(const struct file *file, bool want_upper); |
723 | int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); |
724 | void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, |
725 | struct list_head *list); |
726 | void ovl_cache_free(struct list_head *list); |
727 | void ovl_dir_cache_free(struct inode *inode); |
728 | int ovl_check_d_type_supported(const struct path *realpath); |
729 | int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir, |
730 | struct vfsmount *mnt, struct dentry *dentry, int level); |
731 | int ovl_indexdir_cleanup(struct ovl_fs *ofs); |
732 | |
733 | /* |
734 | * Can we iterate real dir directly? |
735 | * |
736 | * Non-merge dir may contain whiteouts from a time it was a merge upper, before |
737 | * lower dir was removed under it and possibly before it was rotated from upper |
738 | * to lower layer. |
739 | */ |
740 | static inline bool ovl_dir_is_real(struct inode *dir) |
741 | { |
742 | return !ovl_test_flag(flag: OVL_WHITEOUTS, inode: dir); |
743 | } |
744 | |
745 | /* inode.c */ |
746 | int ovl_set_nlink_upper(struct dentry *dentry); |
747 | int ovl_set_nlink_lower(struct dentry *dentry); |
748 | unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, |
749 | struct dentry *upperdentry, |
750 | unsigned int fallback); |
751 | int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, |
752 | int mask); |
753 | |
754 | #ifdef CONFIG_FS_POSIX_ACL |
755 | struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, |
756 | struct inode *inode, int type, |
757 | bool rcu, bool noperm); |
758 | static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, |
759 | bool rcu) |
760 | { |
761 | return do_ovl_get_acl(idmap: &nop_mnt_idmap, inode, type, rcu, noperm: true); |
762 | } |
763 | static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, |
764 | struct dentry *dentry, int type) |
765 | { |
766 | return do_ovl_get_acl(idmap, inode: d_inode(dentry), type, rcu: false, noperm: false); |
767 | } |
768 | int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, |
769 | struct posix_acl *acl, int type); |
770 | struct posix_acl *ovl_get_acl_path(const struct path *path, |
771 | const char *acl_name, bool noperm); |
772 | #else |
773 | #define ovl_get_inode_acl NULL |
774 | #define ovl_get_acl NULL |
775 | #define ovl_set_acl NULL |
776 | static inline struct posix_acl *ovl_get_acl_path(const struct path *path, |
777 | const char *acl_name, |
778 | bool noperm) |
779 | { |
780 | return NULL; |
781 | } |
782 | #endif |
783 | |
784 | int ovl_update_time(struct inode *inode, int flags); |
785 | bool ovl_is_private_xattr(struct super_block *sb, const char *name); |
786 | |
787 | struct ovl_inode_params { |
788 | struct inode *newinode; |
789 | struct dentry *upperdentry; |
790 | struct ovl_entry *oe; |
791 | bool index; |
792 | char *redirect; |
793 | char *lowerdata_redirect; |
794 | }; |
795 | void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, |
796 | unsigned long ino, int fsid); |
797 | struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); |
798 | struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, |
799 | bool is_upper); |
800 | bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); |
801 | struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); |
802 | struct inode *ovl_get_inode(struct super_block *sb, |
803 | struct ovl_inode_params *oip); |
804 | void ovl_copyattr(struct inode *to); |
805 | |
806 | /* vfs inode flags copied from real to ovl inode */ |
807 | #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE) |
808 | /* vfs inode flags read from overlay.protattr xattr to ovl inode */ |
809 | #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) |
810 | |
811 | /* |
812 | * fileattr flags copied from lower to upper inode on copy up. |
813 | * We cannot copy up immutable/append-only flags, because that would prevent |
814 | * linking temp inode to upper dir, so we store them in xattr instead. |
815 | */ |
816 | #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) |
817 | #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) |
818 | #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) |
819 | #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) |
820 | |
821 | void ovl_check_protattr(struct inode *inode, struct dentry *upper); |
822 | int ovl_set_protattr(struct inode *inode, struct dentry *upper, |
823 | struct fileattr *fa); |
824 | |
825 | static inline void ovl_copyflags(struct inode *from, struct inode *to) |
826 | { |
827 | unsigned int mask = OVL_COPY_I_FLAGS_MASK; |
828 | |
829 | inode_set_flags(inode: to, flags: from->i_flags & mask, mask); |
830 | } |
831 | |
832 | /* dir.c */ |
833 | extern const struct inode_operations ovl_dir_inode_operations; |
834 | int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, |
835 | struct dentry *dentry); |
836 | struct ovl_cattr { |
837 | dev_t rdev; |
838 | umode_t mode; |
839 | const char *link; |
840 | struct dentry *hardlink; |
841 | }; |
842 | |
843 | #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) |
844 | |
845 | int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, |
846 | struct dentry **newdentry, umode_t mode); |
847 | struct dentry *ovl_create_real(struct ovl_fs *ofs, |
848 | struct inode *dir, struct dentry *newdentry, |
849 | struct ovl_cattr *attr); |
850 | int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); |
851 | struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); |
852 | struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, |
853 | struct ovl_cattr *attr); |
854 | |
855 | /* file.c */ |
856 | extern const struct file_operations ovl_file_operations; |
857 | int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa); |
858 | int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa); |
859 | int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); |
860 | int ovl_fileattr_set(struct mnt_idmap *idmap, |
861 | struct dentry *dentry, struct fileattr *fa); |
862 | |
863 | /* copy_up.c */ |
864 | int ovl_copy_up(struct dentry *dentry); |
865 | int ovl_copy_up_with_data(struct dentry *dentry); |
866 | int ovl_maybe_copy_up(struct dentry *dentry, int flags); |
867 | int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); |
868 | int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); |
869 | struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, |
870 | bool is_upper); |
871 | struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin); |
872 | int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh, |
873 | struct dentry *upper); |
874 | |
875 | /* export.c */ |
876 | extern const struct export_operations ovl_export_operations; |
877 | extern const struct export_operations ovl_export_fid_operations; |
878 | |
879 | /* super.c */ |
880 | int ovl_fill_super(struct super_block *sb, struct fs_context *fc); |
881 | |
882 | /* Will this overlay be forced to mount/remount ro? */ |
883 | static inline bool ovl_force_readonly(struct ovl_fs *ofs) |
884 | { |
885 | return (!ovl_upper_mnt(ofs) || !ofs->workdir); |
886 | } |
887 | |
888 | /* xattr.c */ |
889 | |
890 | const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs); |
891 | int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, |
892 | struct iattr *attr); |
893 | int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, |
894 | struct kstat *stat, u32 request_mask, unsigned int flags); |
895 | ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); |
896 | |