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 "ovl_entry.h"
11
12 #undef pr_fmt
13 #define pr_fmt(fmt) "overlayfs: " fmt
14
15 enum ovl_path_type {
16 __OVL_PATH_UPPER = (1 << 0),
17 __OVL_PATH_MERGE = (1 << 1),
18 __OVL_PATH_ORIGIN = (1 << 2),
19 };
20
21 #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
22 #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
23 #define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
24
25 #define OVL_XATTR_NAMESPACE "overlay."
26 #define OVL_XATTR_TRUSTED_PREFIX XATTR_TRUSTED_PREFIX OVL_XATTR_NAMESPACE
27 #define OVL_XATTR_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE
28
29 enum ovl_xattr {
30 OVL_XATTR_OPAQUE,
31 OVL_XATTR_REDIRECT,
32 OVL_XATTR_ORIGIN,
33 OVL_XATTR_IMPURE,
34 OVL_XATTR_NLINK,
35 OVL_XATTR_UPPER,
36 OVL_XATTR_METACOPY,
37 OVL_XATTR_PROTATTR,
38 };
39
40 enum ovl_inode_flag {
41 /* Pure upper dir that may contain non pure upper entries */
42 OVL_IMPURE,
43 /* Non-merge dir that may contain whiteout entries */
44 OVL_WHITEOUTS,
45 OVL_INDEX,
46 OVL_UPPERDATA,
47 /* Inode number will remain constant over copy up. */
48 OVL_CONST_INO,
49 };
50
51 enum ovl_entry_flag {
52 OVL_E_UPPER_ALIAS,
53 OVL_E_OPAQUE,
54 OVL_E_CONNECTED,
55 };
56
57 enum {
58 OVL_XINO_OFF,
59 OVL_XINO_AUTO,
60 OVL_XINO_ON,
61 };
62
63 /*
64 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
65 * where:
66 * origin.fh - exported file handle of the lower file
67 * origin.uuid - uuid of the lower filesystem
68 */
69 #define OVL_FH_VERSION 0
70 #define OVL_FH_MAGIC 0xfb
71
72 /* CPU byte order required for fid decoding: */
73 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
74 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
75 /* Is the real inode encoded in fid an upper inode? */
76 #define OVL_FH_FLAG_PATH_UPPER (1 << 2)
77
78 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
79 OVL_FH_FLAG_PATH_UPPER)
80
81 #if defined(__LITTLE_ENDIAN)
82 #define OVL_FH_FLAG_CPU_ENDIAN 0
83 #elif defined(__BIG_ENDIAN)
84 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
85 #else
86 #error Endianness not defined
87 #endif
88
89 /* The type used to be returned by overlay exportfs for misaligned fid */
90 #define OVL_FILEID_V0 0xfb
91 /* The type returned by overlay exportfs for 32bit aligned fid */
92 #define OVL_FILEID_V1 0xf8
93
94 /* On-disk format for "origin" file handle */
95 struct ovl_fb {
96 u8 version; /* 0 */
97 u8 magic; /* 0xfb */
98 u8 len; /* size of this header + size of fid */
99 u8 flags; /* OVL_FH_FLAG_* */
100 u8 type; /* fid_type of fid */
101 uuid_t uuid; /* uuid of filesystem */
102 u32 fid[]; /* file identifier should be 32bit aligned in-memory */
103 } __packed;
104
105 /* In-memory and on-wire format for overlay file handle */
106 struct ovl_fh {
107 u8 padding[3]; /* make sure fb.fid is 32bit aligned */
108 union {
109 struct ovl_fb fb;
110 DECLARE_FLEX_ARRAY(u8, buf);
111 };
112 } __packed;
113
114 #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb)
115 #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len)
116 #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \
117 offsetof(struct ovl_fb, fid))
118
119 extern const char *const ovl_xattr_table[][2];
ovl_xattr(struct ovl_fs * ofs,enum ovl_xattr ox)120 static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox)
121 {
122 return ovl_xattr_table[ox][ofs->config.userxattr];
123 }
124
ovl_do_rmdir(struct inode * dir,struct dentry * dentry)125 static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
126 {
127 int err = vfs_rmdir(&init_user_ns, dir, dentry);
128
129 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
130 return err;
131 }
132
ovl_do_unlink(struct inode * dir,struct dentry * dentry)133 static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
134 {
135 int err = vfs_unlink(&init_user_ns, dir, dentry, NULL);
136
137 pr_debug("unlink(%pd2) = %i\n", dentry, err);
138 return err;
139 }
140
ovl_do_link(struct dentry * old_dentry,struct inode * dir,struct dentry * new_dentry)141 static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
142 struct dentry *new_dentry)
143 {
144 int err = vfs_link(old_dentry, &init_user_ns, dir, new_dentry, NULL);
145
146 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err);
147 return err;
148 }
149
ovl_do_create(struct inode * dir,struct dentry * dentry,umode_t mode)150 static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
151 umode_t mode)
152 {
153 int err = vfs_create(&init_user_ns, dir, dentry, mode, true);
154
155 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
156 return err;
157 }
158
ovl_do_mkdir(struct inode * dir,struct dentry * dentry,umode_t mode)159 static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
160 umode_t mode)
161 {
162 int err = vfs_mkdir(&init_user_ns, dir, dentry, mode);
163 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
164 return err;
165 }
166
ovl_do_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t dev)167 static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
168 umode_t mode, dev_t dev)
169 {
170 int err = vfs_mknod(&init_user_ns, dir, dentry, mode, dev);
171
172 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
173 return err;
174 }
175
ovl_do_symlink(struct inode * dir,struct dentry * dentry,const char * oldname)176 static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
177 const char *oldname)
178 {
179 int err = vfs_symlink(&init_user_ns, dir, dentry, oldname);
180
181 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
182 return err;
183 }
184
ovl_do_getxattr(struct ovl_fs * ofs,struct dentry * dentry,enum ovl_xattr ox,void * value,size_t size)185 static inline ssize_t ovl_do_getxattr(struct ovl_fs *ofs, struct dentry *dentry,
186 enum ovl_xattr ox, void *value,
187 size_t size)
188 {
189 const char *name = ovl_xattr(ofs, ox);
190 int err = vfs_getxattr(&init_user_ns, dentry, name, value, size);
191 int len = (value && err > 0) ? err : 0;
192
193 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n",
194 dentry, name, min(len, 48), value, size, err);
195 return err;
196 }
197
ovl_do_setxattr(struct ovl_fs * ofs,struct dentry * dentry,enum ovl_xattr ox,const void * value,size_t size)198 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
199 enum ovl_xattr ox, const void *value,
200 size_t size)
201 {
202 const char *name = ovl_xattr(ofs, ox);
203 int err = vfs_setxattr(&init_user_ns, dentry, name, value, size, 0);
204 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n",
205 dentry, name, min((int)size, 48), value, size, err);
206 return err;
207 }
208
ovl_do_removexattr(struct ovl_fs * ofs,struct dentry * dentry,enum ovl_xattr ox)209 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry,
210 enum ovl_xattr ox)
211 {
212 const char *name = ovl_xattr(ofs, ox);
213 int err = vfs_removexattr(&init_user_ns, dentry, name);
214 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
215 return err;
216 }
217
ovl_do_rename(struct inode * olddir,struct dentry * olddentry,struct inode * newdir,struct dentry * newdentry,unsigned int flags)218 static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
219 struct inode *newdir, struct dentry *newdentry,
220 unsigned int flags)
221 {
222 int err;
223 struct renamedata rd = {
224 .old_mnt_userns = &init_user_ns,
225 .old_dir = olddir,
226 .old_dentry = olddentry,
227 .new_mnt_userns = &init_user_ns,
228 .new_dir = newdir,
229 .new_dentry = newdentry,
230 .flags = flags,
231 };
232
233 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags);
234 err = vfs_rename(&rd);
235 if (err) {
236 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
237 olddentry, newdentry, err);
238 }
239 return err;
240 }
241
ovl_do_whiteout(struct inode * dir,struct dentry * dentry)242 static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
243 {
244 int err = vfs_whiteout(&init_user_ns, dir, dentry);
245 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
246 return err;
247 }
248
ovl_do_tmpfile(struct dentry * dentry,umode_t mode)249 static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
250 {
251 struct dentry *ret = vfs_tmpfile(&init_user_ns, dentry, mode, 0);
252 int err = PTR_ERR_OR_ZERO(ret);
253
254 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
255 return ret;
256 }
257
ovl_open_flags_need_copy_up(int flags)258 static inline bool ovl_open_flags_need_copy_up(int flags)
259 {
260 if (!flags)
261 return false;
262
263 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
264 }
265
ovl_allow_offline_changes(struct ovl_fs * ofs)266 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs)
267 {
268 /*
269 * To avoid regressions in existing setups with overlay lower offline
270 * changes, we allow lower changes only if none of the new features
271 * are used.
272 */
273 return (!ofs->config.index && !ofs->config.metacopy &&
274 !ofs->config.redirect_dir && ofs->config.xino != OVL_XINO_ON);
275 }
276
277
278 /* util.c */
279 int ovl_want_write(struct dentry *dentry);
280 void ovl_drop_write(struct dentry *dentry);
281 struct dentry *ovl_workdir(struct dentry *dentry);
282 const struct cred *ovl_override_creds(struct super_block *sb);
283 void ovl_revert_creds(struct super_block *sb, const struct cred *oldcred);
284 int ovl_can_decode_fh(struct super_block *sb);
285 struct dentry *ovl_indexdir(struct super_block *sb);
286 bool ovl_index_all(struct super_block *sb);
287 bool ovl_verify_lower(struct super_block *sb);
288 struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
289 bool ovl_dentry_remote(struct dentry *dentry);
290 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry);
291 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry);
292 void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry,
293 unsigned int mask);
294 bool ovl_dentry_weird(struct dentry *dentry);
295 enum ovl_path_type ovl_path_type(struct dentry *dentry);
296 void ovl_path_upper(struct dentry *dentry, struct path *path);
297 void ovl_path_lower(struct dentry *dentry, struct path *path);
298 void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
299 void ovl_i_path_real(struct inode *inode, struct path *path);
300 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
301 struct dentry *ovl_dentry_upper(struct dentry *dentry);
302 struct dentry *ovl_dentry_lower(struct dentry *dentry);
303 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry);
304 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode);
305 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
306 struct dentry *ovl_dentry_real(struct dentry *dentry);
307 struct dentry *ovl_i_dentry_upper(struct inode *inode);
308 struct inode *ovl_inode_upper(struct inode *inode);
309 struct inode *ovl_inode_lower(struct inode *inode);
310 struct inode *ovl_inode_lowerdata(struct inode *inode);
311 struct inode *ovl_inode_real(struct inode *inode);
312 struct inode *ovl_inode_realdata(struct inode *inode);
313 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
314 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
315 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
316 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
317 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
318 bool ovl_dentry_is_opaque(struct dentry *dentry);
319 bool ovl_dentry_is_whiteout(struct dentry *dentry);
320 void ovl_dentry_set_opaque(struct dentry *dentry);
321 bool ovl_dentry_has_upper_alias(struct dentry *dentry);
322 void ovl_dentry_set_upper_alias(struct dentry *dentry);
323 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
324 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags);
325 bool ovl_has_upperdata(struct inode *inode);
326 void ovl_set_upperdata(struct inode *inode);
327 bool ovl_redirect_dir(struct super_block *sb);
328 const char *ovl_dentry_get_redirect(struct dentry *dentry);
329 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
330 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
331 void ovl_dir_modified(struct dentry *dentry, bool impurity);
332 u64 ovl_dentry_version_get(struct dentry *dentry);
333 bool ovl_is_whiteout(struct dentry *dentry);
334 struct file *ovl_path_open(struct path *path, int flags);
335 int ovl_copy_up_start(struct dentry *dentry, int flags);
336 void ovl_copy_up_end(struct dentry *dentry);
337 bool ovl_already_copied_up(struct dentry *dentry, int flags);
338 bool ovl_check_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry);
339 bool ovl_check_dir_xattr(struct super_block *sb, struct dentry *dentry,
340 enum ovl_xattr ox);
341 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry,
342 enum ovl_xattr ox, const void *value, size_t size,
343 int xerr);
344 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
345 bool ovl_inuse_trylock(struct dentry *dentry);
346 void ovl_inuse_unlock(struct dentry *dentry);
347 bool ovl_is_inuse(struct dentry *dentry);
348 bool ovl_need_index(struct dentry *dentry);
349 int ovl_nlink_start(struct dentry *dentry);
350 void ovl_nlink_end(struct dentry *dentry);
351 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
352 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, struct dentry *dentry);
353 bool ovl_is_metacopy_dentry(struct dentry *dentry);
354 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, struct dentry *dentry,
355 int padding);
356 int ovl_sync_status(struct ovl_fs *ofs);
357
ovl_set_flag(unsigned long flag,struct inode * inode)358 static inline void ovl_set_flag(unsigned long flag, struct inode *inode)
359 {
360 set_bit(flag, &OVL_I(inode)->flags);
361 }
362
ovl_clear_flag(unsigned long flag,struct inode * inode)363 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode)
364 {
365 clear_bit(flag, &OVL_I(inode)->flags);
366 }
367
ovl_test_flag(unsigned long flag,struct inode * inode)368 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode)
369 {
370 return test_bit(flag, &OVL_I(inode)->flags);
371 }
372
ovl_is_impuredir(struct super_block * sb,struct dentry * dentry)373 static inline bool ovl_is_impuredir(struct super_block *sb,
374 struct dentry *dentry)
375 {
376 return ovl_check_dir_xattr(sb, dentry, OVL_XATTR_IMPURE);
377 }
378
379 /*
380 * With xino=auto, we do best effort to keep all inodes on same st_dev and
381 * d_ino consistent with st_ino.
382 * With xino=on, we do the same effort but we warn if we failed.
383 */
ovl_xino_warn(struct super_block * sb)384 static inline bool ovl_xino_warn(struct super_block *sb)
385 {
386 return OVL_FS(sb)->config.xino == OVL_XINO_ON;
387 }
388
389 /* All layers on same fs? */
ovl_same_fs(struct super_block * sb)390 static inline bool ovl_same_fs(struct super_block *sb)
391 {
392 return OVL_FS(sb)->xino_mode == 0;
393 }
394
395 /* All overlay inodes have same st_dev? */
ovl_same_dev(struct super_block * sb)396 static inline bool ovl_same_dev(struct super_block *sb)
397 {
398 return OVL_FS(sb)->xino_mode >= 0;
399 }
400
ovl_xino_bits(struct super_block * sb)401 static inline unsigned int ovl_xino_bits(struct super_block *sb)
402 {
403 return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0;
404 }
405
ovl_inode_lock(struct inode * inode)406 static inline void ovl_inode_lock(struct inode *inode)
407 {
408 mutex_lock(&OVL_I(inode)->lock);
409 }
410
ovl_inode_lock_interruptible(struct inode * inode)411 static inline int ovl_inode_lock_interruptible(struct inode *inode)
412 {
413 return mutex_lock_interruptible(&OVL_I(inode)->lock);
414 }
415
ovl_inode_unlock(struct inode * inode)416 static inline void ovl_inode_unlock(struct inode *inode)
417 {
418 mutex_unlock(&OVL_I(inode)->lock);
419 }
420
421
422 /* namei.c */
423 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len);
424
ovl_check_fh_len(struct ovl_fh * fh,int fh_len)425 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len)
426 {
427 if (fh_len < sizeof(struct ovl_fh))
428 return -EINVAL;
429
430 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET);
431 }
432
433 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh,
434 struct vfsmount *mnt, bool connected);
435 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
436 struct dentry *upperdentry, struct ovl_path **stackp);
437 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry,
438 enum ovl_xattr ox, struct dentry *real, bool is_upper,
439 bool set);
440 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
441 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
442 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin,
443 struct qstr *name);
444 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
445 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
446 struct dentry *origin, bool verify);
447 int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
448 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
449 unsigned int flags);
450 bool ovl_lower_positive(struct dentry *dentry);
451
ovl_verify_origin(struct ovl_fs * ofs,struct dentry * upper,struct dentry * origin,bool set)452 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper,
453 struct dentry *origin, bool set)
454 {
455 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, origin,
456 false, set);
457 }
458
ovl_verify_upper(struct ovl_fs * ofs,struct dentry * index,struct dentry * upper,bool set)459 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index,
460 struct dentry *upper, bool set)
461 {
462 return ovl_verify_set_fh(ofs, index, OVL_XATTR_UPPER, upper, true, set);
463 }
464
465 /* readdir.c */
466 extern const struct file_operations ovl_dir_operations;
467 struct file *ovl_dir_real_file(const struct file *file, bool want_upper);
468 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
469 void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
470 void ovl_cache_free(struct list_head *list);
471 void ovl_dir_cache_free(struct inode *inode);
472 int ovl_check_d_type_supported(struct path *realpath);
473 int ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
474 struct dentry *dentry, int level);
475 int ovl_indexdir_cleanup(struct ovl_fs *ofs);
476
477 /*
478 * Can we iterate real dir directly?
479 *
480 * Non-merge dir may contain whiteouts from a time it was a merge upper, before
481 * lower dir was removed under it and possibly before it was rotated from upper
482 * to lower layer.
483 */
ovl_dir_is_real(struct dentry * dir)484 static inline bool ovl_dir_is_real(struct dentry *dir)
485 {
486 return !ovl_test_flag(OVL_WHITEOUTS, d_inode(dir));
487 }
488
489 /* inode.c */
490 int ovl_set_nlink_upper(struct dentry *dentry);
491 int ovl_set_nlink_lower(struct dentry *dentry);
492 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry,
493 struct dentry *upperdentry,
494 unsigned int fallback);
495 int ovl_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
496 struct iattr *attr);
497 int ovl_getattr(struct user_namespace *mnt_userns, const struct path *path,
498 struct kstat *stat, u32 request_mask, unsigned int flags);
499 int ovl_permission(struct user_namespace *mnt_userns, struct inode *inode,
500 int mask);
501 int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
502 const void *value, size_t size, int flags);
503 int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
504 void *value, size_t size);
505 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
506 struct posix_acl *ovl_get_acl(struct inode *inode, int type, bool rcu);
507 int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);
508 bool ovl_is_private_xattr(struct super_block *sb, const char *name);
509
510 struct ovl_inode_params {
511 struct inode *newinode;
512 struct dentry *upperdentry;
513 struct ovl_path *lowerpath;
514 bool index;
515 unsigned int numlower;
516 char *redirect;
517 struct dentry *lowerdata;
518 };
519 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,
520 unsigned long ino, int fsid);
521 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
522 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
523 bool is_upper);
524 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir);
525 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir);
526 struct inode *ovl_get_inode(struct super_block *sb,
527 struct ovl_inode_params *oip);
528 void ovl_copyattr(struct inode *to);
529
530 /* vfs inode flags copied from real to ovl inode */
531 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE)
532 /* vfs inode flags read from overlay.protattr xattr to ovl inode */
533 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE)
534
535 /*
536 * fileattr flags copied from lower to upper inode on copy up.
537 * We cannot copy up immutable/append-only flags, because that would prevent
538 * linking temp inode to upper dir, so we store them in xattr instead.
539 */
540 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL)
541 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME)
542 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL)
543 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE)
544
545 void ovl_check_protattr(struct inode *inode, struct dentry *upper);
546 int ovl_set_protattr(struct inode *inode, struct dentry *upper,
547 struct fileattr *fa);
548
ovl_copyflags(struct inode * from,struct inode * to)549 static inline void ovl_copyflags(struct inode *from, struct inode *to)
550 {
551 unsigned int mask = OVL_COPY_I_FLAGS_MASK;
552
553 inode_set_flags(to, from->i_flags & mask, mask);
554 }
555
556 /* dir.c */
557 extern const struct inode_operations ovl_dir_inode_operations;
558 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir,
559 struct dentry *dentry);
560 struct ovl_cattr {
561 dev_t rdev;
562 umode_t mode;
563 const char *link;
564 struct dentry *hardlink;
565 };
566
567 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
568
569 int ovl_mkdir_real(struct inode *dir, struct dentry **newdentry, umode_t mode);
570 struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
571 struct ovl_cattr *attr);
572 int ovl_cleanup(struct inode *dir, struct dentry *dentry);
573 struct dentry *ovl_lookup_temp(struct dentry *workdir);
574 struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
575
576 /* file.c */
577 extern const struct file_operations ovl_file_operations;
578 int __init ovl_aio_request_cache_init(void);
579 void ovl_aio_request_cache_destroy(void);
580 int ovl_real_fileattr_get(struct path *realpath, struct fileattr *fa);
581 int ovl_real_fileattr_set(struct path *realpath, struct fileattr *fa);
582 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa);
583 int ovl_fileattr_set(struct user_namespace *mnt_userns,
584 struct dentry *dentry, struct fileattr *fa);
585
586 /* copy_up.c */
587 int ovl_copy_up(struct dentry *dentry);
588 int ovl_copy_up_with_data(struct dentry *dentry);
589 int ovl_maybe_copy_up(struct dentry *dentry, int flags);
590 int ovl_copy_xattr(struct super_block *sb, struct dentry *old,
591 struct dentry *new);
592 int ovl_set_attr(struct dentry *upper, struct kstat *stat);
593 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real,
594 bool is_upper);
595 int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower,
596 struct dentry *upper);
597
598 /* export.c */
599 extern const struct export_operations ovl_export_operations;
600