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