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