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/namei.h>
11 #include "ovl_entry.h"
12
13 #undef pr_fmt
14 #define pr_fmt(fmt) "overlayfs: " fmt
15
16 enum ovl_path_type {
17 __OVL_PATH_UPPER = (1 << 0),
18 __OVL_PATH_MERGE = (1 << 1),
19 __OVL_PATH_ORIGIN = (1 << 2),
20 };
21
22 #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
23 #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
24 #define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
25
26 #define OVL_XATTR_NAMESPACE "overlay."
27 #define OVL_XATTR_TRUSTED_PREFIX XATTR_TRUSTED_PREFIX OVL_XATTR_NAMESPACE
28 #define OVL_XATTR_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE
29
30 enum ovl_xattr {
31 OVL_XATTR_OPAQUE,
32 OVL_XATTR_REDIRECT,
33 OVL_XATTR_ORIGIN,
34 OVL_XATTR_IMPURE,
35 OVL_XATTR_NLINK,
36 OVL_XATTR_UPPER,
37 OVL_XATTR_METACOPY,
38 OVL_XATTR_PROTATTR,
39 };
40
41 enum ovl_inode_flag {
42 /* Pure upper dir that may contain non pure upper entries */
43 OVL_IMPURE,
44 /* Non-merge dir that may contain whiteout entries */
45 OVL_WHITEOUTS,
46 OVL_INDEX,
47 OVL_UPPERDATA,
48 /* Inode number will remain constant over copy up. */
49 OVL_CONST_INO,
50 };
51
52 enum ovl_entry_flag {
53 OVL_E_UPPER_ALIAS,
54 OVL_E_OPAQUE,
55 OVL_E_CONNECTED,
56 };
57
58 enum {
59 OVL_XINO_OFF,
60 OVL_XINO_AUTO,
61 OVL_XINO_ON,
62 };
63
64 /*
65 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
66 * where:
67 * origin.fh - exported file handle of the lower file
68 * origin.uuid - uuid of the lower filesystem
69 */
70 #define OVL_FH_VERSION 0
71 #define OVL_FH_MAGIC 0xfb
72
73 /* CPU byte order required for fid decoding: */
74 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
75 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
76 /* Is the real inode encoded in fid an upper inode? */
77 #define OVL_FH_FLAG_PATH_UPPER (1 << 2)
78
79 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
80 OVL_FH_FLAG_PATH_UPPER)
81
82 #if defined(__LITTLE_ENDIAN)
83 #define OVL_FH_FLAG_CPU_ENDIAN 0
84 #elif defined(__BIG_ENDIAN)
85 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
86 #else
87 #error Endianness not defined
88 #endif
89
90 /* The type used to be returned by overlay exportfs for misaligned fid */
91 #define OVL_FILEID_V0 0xfb
92 /* The type returned by overlay exportfs for 32bit aligned fid */
93 #define OVL_FILEID_V1 0xf8
94
95 /* On-disk format for "origin" file handle */
96 struct ovl_fb {
97 u8 version; /* 0 */
98 u8 magic; /* 0xfb */
99 u8 len; /* size of this header + size of fid */
100 u8 flags; /* OVL_FH_FLAG_* */
101 u8 type; /* fid_type of fid */
102 uuid_t uuid; /* uuid of filesystem */
103 u32 fid[]; /* file identifier should be 32bit aligned in-memory */
104 } __packed;
105
106 /* In-memory and on-wire format for overlay file handle */
107 struct ovl_fh {
108 u8 padding[3]; /* make sure fb.fid is 32bit aligned */
109 union {
110 struct ovl_fb fb;
111 u8 buf[0];
112 };
113 } __packed;
114
115 #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb)
116 #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len)
117 #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \
118 offsetof(struct ovl_fb, fid))
119
120 extern const char *const ovl_xattr_table[][2];
ovl_xattr(struct ovl_fs * ofs,enum ovl_xattr ox)121 static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox)
122 {
123 return ovl_xattr_table[ox][ofs->config.userxattr];
124 }
125
126 /*
127 * When changing ownership of an upper object map the intended ownership
128 * according to the upper layer's idmapping. When an upper mount idmaps files
129 * that are stored on-disk as owned by id 1001 to id 1000 this means stat on
130 * this object will report it as being owned by id 1000 when calling stat via
131 * the upper mount.
132 * In order to change ownership of an object so stat reports id 1000 when
133 * called on an idmapped upper mount the value written to disk - i.e., the
134 * value stored in ia_*id - must 1001. The mount mapping helper will thus take
135 * care to map 1000 to 1001.
136 * The mnt idmapping helpers are nops if the upper layer isn't idmapped.
137 */
ovl_do_notify_change(struct ovl_fs * ofs,struct dentry * upperdentry,struct iattr * attr)138 static inline int ovl_do_notify_change(struct ovl_fs *ofs,
139 struct dentry *upperdentry,
140 struct iattr *attr)
141 {
142 return notify_change(ovl_upper_mnt_userns(ofs), upperdentry, attr, NULL);
143 }
144
ovl_do_rmdir(struct ovl_fs * ofs,struct inode * dir,struct dentry * dentry)145 static inline int ovl_do_rmdir(struct ovl_fs *ofs,
146 struct inode *dir, struct dentry *dentry)
147 {
148 int err = vfs_rmdir(ovl_upper_mnt_userns(ofs), dir, dentry);
149
150 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
151 return err;
152 }
153
ovl_do_unlink(struct ovl_fs * ofs,struct inode * dir,struct dentry * dentry)154 static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir,
155 struct dentry *dentry)
156 {
157 int err = vfs_unlink(ovl_upper_mnt_userns(ofs), dir, dentry, NULL);
158
159 pr_debug("unlink(%pd2) = %i\n", dentry, err);
160 return err;
161 }
162
ovl_do_link(struct ovl_fs * ofs,struct dentry * old_dentry,struct inode * dir,struct dentry * new_dentry)163 static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry,
164 struct inode *dir, struct dentry *new_dentry)
165 {
166 int err = vfs_link(old_dentry, ovl_upper_mnt_userns(ofs), dir, new_dentry, NULL);
167
168 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err);
169 return err;
170 }
171
ovl_do_create(struct ovl_fs * ofs,struct inode * dir,struct dentry * dentry,umode_t mode)172 static inline int ovl_do_create(struct ovl_fs *ofs,
173 struct inode *dir, struct dentry *dentry,
174 umode_t mode)
175 {
176 int err = vfs_create(ovl_upper_mnt_userns(ofs), dir, dentry, mode, true);
177
178 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
179 return err;
180 }
181
ovl_do_mkdir(struct ovl_fs * ofs,struct inode * dir,struct dentry * dentry,umode_t mode)182 static inline int ovl_do_mkdir(struct ovl_fs *ofs,
183 struct inode *dir, struct dentry *dentry,
184 umode_t mode)
185 {
186 int err = vfs_mkdir(ovl_upper_mnt_userns(ofs), dir, dentry, mode);
187 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
188 return err;
189 }
190
ovl_do_mknod(struct ovl_fs * ofs,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t dev)191 static inline int ovl_do_mknod(struct ovl_fs *ofs,
192 struct inode *dir, struct dentry *dentry,
193 umode_t mode, dev_t dev)
194 {
195 int err = vfs_mknod(ovl_upper_mnt_userns(ofs), dir, dentry, mode, dev);
196
197 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
198 return err;
199 }
200
ovl_do_symlink(struct ovl_fs * ofs,struct inode * dir,struct dentry * dentry,const char * oldname)201 static inline int ovl_do_symlink(struct ovl_fs *ofs,
202 struct inode *dir, struct dentry *dentry,
203 const char *oldname)
204 {
205 int err = vfs_symlink(ovl_upper_mnt_userns(ofs), dir, dentry, oldname);
206
207 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
208 return err;
209 }
210
ovl_do_getxattr(const struct path * path,const char * name,void * value,size_t size)211 static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name,
212 void *value, size_t size)
213 {
214 int err, len;
215
216 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb);
217
218 err = vfs_getxattr(mnt_user_ns(path->mnt), path->dentry,
219 name, value, size);
220 len = (value && err > 0) ? err : 0;
221
222 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n",
223 path->dentry, name, min(len, 48), value, size, err);
224 return err;
225 }
226
ovl_getxattr_upper(struct ovl_fs * ofs,struct dentry * upperdentry,enum ovl_xattr ox,void * value,size_t size)227 static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs,
228 struct dentry *upperdentry,
229 enum ovl_xattr ox, void *value,
230 size_t size)
231 {
232 struct path upperpath = {
233 .dentry = upperdentry,
234 .mnt = ovl_upper_mnt(ofs),
235 };
236
237 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size);
238 }
239
ovl_path_getxattr(struct ovl_fs * ofs,const struct path * path,enum ovl_xattr ox,void * value,size_t size)240 static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs,
241 const struct path *path,
242 enum ovl_xattr ox, void *value,
243 size_t size)
244 {
245 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size);
246 }
247
ovl_do_setxattr(struct ovl_fs * ofs,struct dentry * dentry,const char * name,const void * value,size_t size,int flags)248 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
249 const char *name, const void *value,
250 size_t size, int flags)
251 {
252 int err = vfs_setxattr(ovl_upper_mnt_userns(ofs), dentry, name,
253 value, size, flags);
254
255 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n",
256 dentry, name, min((int)size, 48), value, size, flags, err);
257 return err;
258 }
259
ovl_setxattr(struct ovl_fs * ofs,struct dentry * dentry,enum ovl_xattr ox,const void * value,size_t size)260 static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
261 enum ovl_xattr ox, const void *value,
262 size_t size)
263 {
264 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0);
265 }
266
ovl_do_removexattr(struct ovl_fs * ofs,struct dentry * dentry,const char * name)267 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry,
268 const char *name)
269 {
270 int err = vfs_removexattr(ovl_upper_mnt_userns(ofs), dentry, name);
271 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
272 return err;
273 }
274
ovl_removexattr(struct ovl_fs * ofs,struct dentry * dentry,enum ovl_xattr ox)275 static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry,
276 enum ovl_xattr ox)
277 {
278 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox));
279 }
280
ovl_do_rename(struct ovl_fs * ofs,struct inode * olddir,struct dentry * olddentry,struct inode * newdir,struct dentry * newdentry,unsigned int flags)281 static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir,
282 struct dentry *olddentry, struct inode *newdir,
283 struct dentry *newdentry, unsigned int flags)
284 {
285 int err;
286 struct renamedata rd = {
287 .old_mnt_userns = ovl_upper_mnt_userns(ofs),
288 .old_dir = olddir,
289 .old_dentry = olddentry,
290 .new_mnt_userns = ovl_upper_mnt_userns(ofs),
291 .new_dir = newdir,
292 .new_dentry = newdentry,
293 .flags = flags,
294 };
295
296 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags);
297 err = vfs_rename(&rd);
298 if (err) {
299 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
300 olddentry, newdentry, err);
301 }
302 return err;
303 }
304
ovl_do_whiteout(struct ovl_fs * ofs,struct inode * dir,struct dentry * dentry)305 static inline int ovl_do_whiteout(struct ovl_fs *ofs,
306 struct inode *dir, struct dentry *dentry)
307 {
308 int err = vfs_whiteout(ovl_upper_mnt_userns(ofs), dir, dentry);
309 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
310 return err;
311 }
312
ovl_do_tmpfile(struct ovl_fs * ofs,struct dentry * dentry,umode_t mode)313 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs,
314 struct dentry *dentry, umode_t mode)
315 {
316 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry };
317 struct file *file = vfs_tmpfile_open(ovl_upper_mnt_userns(ofs), &path, mode,
318 O_LARGEFILE | O_WRONLY, current_cred());
319 int err = PTR_ERR_OR_ZERO(file);
320
321 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
322 return file;
323 }
324
ovl_lookup_upper(struct ovl_fs * ofs,const char * name,struct dentry * base,int len)325 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs,
326 const char *name,
327 struct dentry *base, int len)
328 {
329 return lookup_one(ovl_upper_mnt_userns(ofs), name, base, len);
330 }
331
ovl_open_flags_need_copy_up(int flags)332 static inline bool ovl_open_flags_need_copy_up(int flags)
333 {
334 if (!flags)
335 return false;
336
337 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
338 }
339
ovl_allow_offline_changes(struct ovl_fs * ofs)340 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs)
341 {
342 /*
343 * To avoid regressions in existing setups with overlay lower offline
344 * changes, we allow lower changes only if none of the new features
345 * are used.
346 */
347 return (!ofs->config.index && !ofs->config.metacopy &&
348 !ofs->config.redirect_dir && ofs->config.xino != OVL_XINO_ON);
349 }
350
351
352 /* util.c */
353 int ovl_want_write(struct dentry *dentry);
354 void ovl_drop_write(struct dentry *dentry);
355 struct dentry *ovl_workdir(struct dentry *dentry);
356 const struct cred *ovl_override_creds(struct super_block *sb);
357 int ovl_can_decode_fh(struct super_block *sb);
358 struct dentry *ovl_indexdir(struct super_block *sb);
359 bool ovl_index_all(struct super_block *sb);
360 bool ovl_verify_lower(struct super_block *sb);
361 struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
362 bool ovl_dentry_remote(struct dentry *dentry);
363 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry,
364 unsigned int mask);
365 bool ovl_dentry_weird(struct dentry *dentry);
366 enum ovl_path_type ovl_path_type(struct dentry *dentry);
367 void ovl_path_upper(struct dentry *dentry, struct path *path);
368 void ovl_path_lower(struct dentry *dentry, struct path *path);
369 void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
370 void ovl_i_path_real(struct inode *inode, struct path *path);
371 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
372 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path);
373 struct dentry *ovl_dentry_upper(struct dentry *dentry);
374 struct dentry *ovl_dentry_lower(struct dentry *dentry);
375 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry);
376 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode);
377 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
378 struct dentry *ovl_dentry_real(struct dentry *dentry);
379 struct dentry *ovl_i_dentry_upper(struct inode *inode);
380 struct inode *ovl_inode_upper(struct inode *inode);
381 struct inode *ovl_inode_lower(struct inode *inode);
382 struct inode *ovl_inode_lowerdata(struct inode *inode);
383 struct inode *ovl_inode_real(struct inode *inode);
384 struct inode *ovl_inode_realdata(struct inode *inode);
385 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
386 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
387 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
388 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
389 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
390 bool ovl_dentry_is_opaque(struct dentry *dentry);
391 bool ovl_dentry_is_whiteout(struct dentry *dentry);
392 void ovl_dentry_set_opaque(struct dentry *dentry);
393 bool ovl_dentry_has_upper_alias(struct dentry *dentry);
394 void ovl_dentry_set_upper_alias(struct dentry *dentry);
395 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
396 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags);
397 bool ovl_has_upperdata(struct inode *inode);
398 void ovl_set_upperdata(struct inode *inode);
399 bool ovl_redirect_dir(struct super_block *sb);
400 const char *ovl_dentry_get_redirect(struct dentry *dentry);
401 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
402 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
403 void ovl_dir_modified(struct dentry *dentry, bool impurity);
404 u64 ovl_dentry_version_get(struct dentry *dentry);
405 bool ovl_is_whiteout(struct dentry *dentry);
406 struct file *ovl_path_open(const struct path *path, int flags);
407 int ovl_copy_up_start(struct dentry *dentry, int flags);
408 void ovl_copy_up_end(struct dentry *dentry);
409 bool ovl_already_copied_up(struct dentry *dentry, int flags);
410 bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path,
411 enum ovl_xattr ox);
412 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path);
413
ovl_check_origin_xattr(struct ovl_fs * ofs,struct dentry * upperdentry)414 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs,
415 struct dentry *upperdentry)
416 {
417 struct path upperpath = {
418 .dentry = upperdentry,
419 .mnt = ovl_upper_mnt(ofs),
420 };
421 return ovl_path_check_origin_xattr(ofs, &upperpath);
422 }
423
424 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry,
425 enum ovl_xattr ox, const void *value, size_t size,
426 int xerr);
427 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
428 bool ovl_inuse_trylock(struct dentry *dentry);
429 void ovl_inuse_unlock(struct dentry *dentry);
430 bool ovl_is_inuse(struct dentry *dentry);
431 bool ovl_need_index(struct dentry *dentry);
432 int ovl_nlink_start(struct dentry *dentry);
433 void ovl_nlink_end(struct dentry *dentry);
434 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
435 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path);
436 bool ovl_is_metacopy_dentry(struct dentry *dentry);
437 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding);
438 int ovl_sync_status(struct ovl_fs *ofs);
439
ovl_set_flag(unsigned long flag,struct inode * inode)440 static inline void ovl_set_flag(unsigned long flag, struct inode *inode)
441 {
442 set_bit(flag, &OVL_I(inode)->flags);
443 }
444
ovl_clear_flag(unsigned long flag,struct inode * inode)445 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode)
446 {
447 clear_bit(flag, &OVL_I(inode)->flags);
448 }
449
ovl_test_flag(unsigned long flag,struct inode * inode)450 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode)
451 {
452 return test_bit(flag, &OVL_I(inode)->flags);
453 }
454
ovl_is_impuredir(struct super_block * sb,struct dentry * upperdentry)455 static inline bool ovl_is_impuredir(struct super_block *sb,
456 struct dentry *upperdentry)
457 {
458 struct ovl_fs *ofs = OVL_FS(sb);
459 struct path upperpath = {
460 .dentry = upperdentry,
461 .mnt = ovl_upper_mnt(ofs),
462 };
463
464 return ovl_path_check_dir_xattr(ofs, &upperpath, OVL_XATTR_IMPURE);
465 }
466
467 /*
468 * With xino=auto, we do best effort to keep all inodes on same st_dev and
469 * d_ino consistent with st_ino.
470 * With xino=on, we do the same effort but we warn if we failed.
471 */
ovl_xino_warn(struct super_block * sb)472 static inline bool ovl_xino_warn(struct super_block *sb)
473 {
474 return OVL_FS(sb)->config.xino == OVL_XINO_ON;
475 }
476
477 /* All layers on same fs? */
ovl_same_fs(struct super_block * sb)478 static inline bool ovl_same_fs(struct super_block *sb)
479 {
480 return OVL_FS(sb)->xino_mode == 0;
481 }
482
483 /* All overlay inodes have same st_dev? */
ovl_same_dev(struct super_block * sb)484 static inline bool ovl_same_dev(struct super_block *sb)
485 {
486 return OVL_FS(sb)->xino_mode >= 0;
487 }
488
ovl_xino_bits(struct super_block * sb)489 static inline unsigned int ovl_xino_bits(struct super_block *sb)
490 {
491 return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0;
492 }
493
ovl_inode_lock(struct inode * inode)494 static inline void ovl_inode_lock(struct inode *inode)
495 {
496 mutex_lock(&OVL_I(inode)->lock);
497 }
498
ovl_inode_lock_interruptible(struct inode * inode)499 static inline int ovl_inode_lock_interruptible(struct inode *inode)
500 {
501 return mutex_lock_interruptible(&OVL_I(inode)->lock);
502 }
503
ovl_inode_unlock(struct inode * inode)504 static inline void ovl_inode_unlock(struct inode *inode)
505 {
506 mutex_unlock(&OVL_I(inode)->lock);
507 }
508
509
510 /* namei.c */
511 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len);
512
ovl_check_fh_len(struct ovl_fh * fh,int fh_len)513 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len)
514 {
515 if (fh_len < sizeof(struct ovl_fh))
516 return -EINVAL;
517
518 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET);
519 }
520
521 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh,
522 struct vfsmount *mnt, bool connected);
523 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
524 struct dentry *upperdentry, struct ovl_path **stackp);
525 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry,
526 enum ovl_xattr ox, struct dentry *real, bool is_upper,
527 bool set);
528 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
529 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
530 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin,
531 struct qstr *name);
532 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
533 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
534 struct dentry *origin, bool verify);
535 int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
536 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
537 unsigned int flags);
538 bool ovl_lower_positive(struct dentry *dentry);
539
ovl_verify_origin(struct ovl_fs * ofs,struct dentry * upper,struct dentry * origin,bool set)540 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper,
541 struct dentry *origin, bool set)
542 {
543 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, origin,
544 false, set);
545 }
546
ovl_verify_upper(struct ovl_fs * ofs,struct dentry * index,struct dentry * upper,bool set)547 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index,
548 struct dentry *upper, bool set)
549 {
550 return ovl_verify_set_fh(ofs, index, OVL_XATTR_UPPER, upper, true, set);
551 }
552
553 /* readdir.c */
554 extern const struct file_operations ovl_dir_operations;
555 struct file *ovl_dir_real_file(const struct file *file, bool want_upper);
556 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
557 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper,
558 struct list_head *list);
559 void ovl_cache_free(struct list_head *list);
560 void ovl_dir_cache_free(struct inode *inode);
561 int ovl_check_d_type_supported(const struct path *realpath);
562 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir,
563 struct vfsmount *mnt, struct dentry *dentry, int level);
564 int ovl_indexdir_cleanup(struct ovl_fs *ofs);
565
566 /*
567 * Can we iterate real dir directly?
568 *
569 * Non-merge dir may contain whiteouts from a time it was a merge upper, before
570 * lower dir was removed under it and possibly before it was rotated from upper
571 * to lower layer.
572 */
ovl_dir_is_real(struct dentry * dir)573 static inline bool ovl_dir_is_real(struct dentry *dir)
574 {
575 return !ovl_test_flag(OVL_WHITEOUTS, d_inode(dir));
576 }
577
578 /* inode.c */
579 int ovl_set_nlink_upper(struct dentry *dentry);
580 int ovl_set_nlink_lower(struct dentry *dentry);
581 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry,
582 struct dentry *upperdentry,
583 unsigned int fallback);
584 int ovl_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
585 struct iattr *attr);
586 int ovl_getattr(struct user_namespace *mnt_userns, const struct path *path,
587 struct kstat *stat, u32 request_mask, unsigned int flags);
588 int ovl_permission(struct user_namespace *mnt_userns, struct inode *inode,
589 int mask);
590 int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
591 const void *value, size_t size, int flags);
592 int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
593 void *value, size_t size);
594 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
595
596 #ifdef CONFIG_FS_POSIX_ACL
597 struct posix_acl *ovl_get_acl(struct inode *inode, int type, bool rcu);
598 #else
599 #define ovl_get_acl NULL
600 #endif
601
602 int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);
603 bool ovl_is_private_xattr(struct super_block *sb, const char *name);
604
605 struct ovl_inode_params {
606 struct inode *newinode;
607 struct dentry *upperdentry;
608 struct ovl_path *lowerpath;
609 bool index;
610 unsigned int numlower;
611 char *redirect;
612 struct dentry *lowerdata;
613 };
614 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,
615 unsigned long ino, int fsid);
616 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
617 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
618 bool is_upper);
619 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir);
620 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir);
621 struct inode *ovl_get_inode(struct super_block *sb,
622 struct ovl_inode_params *oip);
623 void ovl_copyattr(struct inode *to);
624
625 /* vfs inode flags copied from real to ovl inode */
626 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE)
627 /* vfs inode flags read from overlay.protattr xattr to ovl inode */
628 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE)
629
630 /*
631 * fileattr flags copied from lower to upper inode on copy up.
632 * We cannot copy up immutable/append-only flags, because that would prevent
633 * linking temp inode to upper dir, so we store them in xattr instead.
634 */
635 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL)
636 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME)
637 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL)
638 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE)
639
640 void ovl_check_protattr(struct inode *inode, struct dentry *upper);
641 int ovl_set_protattr(struct inode *inode, struct dentry *upper,
642 struct fileattr *fa);
643
ovl_copyflags(struct inode * from,struct inode * to)644 static inline void ovl_copyflags(struct inode *from, struct inode *to)
645 {
646 unsigned int mask = OVL_COPY_I_FLAGS_MASK;
647
648 inode_set_flags(to, from->i_flags & mask, mask);
649 }
650
651 /* dir.c */
652 extern const struct inode_operations ovl_dir_inode_operations;
653 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir,
654 struct dentry *dentry);
655 struct ovl_cattr {
656 dev_t rdev;
657 umode_t mode;
658 const char *link;
659 struct dentry *hardlink;
660 };
661
662 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
663
664 int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir,
665 struct dentry **newdentry, umode_t mode);
666 struct dentry *ovl_create_real(struct ovl_fs *ofs,
667 struct inode *dir, struct dentry *newdentry,
668 struct ovl_cattr *attr);
669 int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry);
670 struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir);
671 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir,
672 struct ovl_cattr *attr);
673
674 /* file.c */
675 extern const struct file_operations ovl_file_operations;
676 int __init ovl_aio_request_cache_init(void);
677 void ovl_aio_request_cache_destroy(void);
678 int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa);
679 int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa);
680 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa);
681 int ovl_fileattr_set(struct user_namespace *mnt_userns,
682 struct dentry *dentry, struct fileattr *fa);
683
684 /* copy_up.c */
685 int ovl_copy_up(struct dentry *dentry);
686 int ovl_copy_up_with_data(struct dentry *dentry);
687 int ovl_maybe_copy_up(struct dentry *dentry, int flags);
688 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new);
689 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat);
690 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real,
691 bool is_upper);
692 int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower,
693 struct dentry *upper);
694
695 /* export.c */
696 extern const struct export_operations ovl_export_operations;
697