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 <linux/posix_acl.h> 12 #include <linux/posix_acl_xattr.h> 13 #include "ovl_entry.h" 14 15 #undef pr_fmt 16 #define pr_fmt(fmt) "overlayfs: " fmt 17 18 enum ovl_path_type { 19 __OVL_PATH_UPPER = (1 << 0), 20 __OVL_PATH_MERGE = (1 << 1), 21 __OVL_PATH_ORIGIN = (1 << 2), 22 }; 23 24 #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER) 25 #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE) 26 #define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN) 27 28 #define OVL_XATTR_NAMESPACE "overlay." 29 #define OVL_XATTR_TRUSTED_PREFIX XATTR_TRUSTED_PREFIX OVL_XATTR_NAMESPACE 30 #define OVL_XATTR_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE 31 32 enum ovl_xattr { 33 OVL_XATTR_OPAQUE, 34 OVL_XATTR_REDIRECT, 35 OVL_XATTR_ORIGIN, 36 OVL_XATTR_IMPURE, 37 OVL_XATTR_NLINK, 38 OVL_XATTR_UPPER, 39 OVL_XATTR_METACOPY, 40 OVL_XATTR_PROTATTR, 41 }; 42 43 enum ovl_inode_flag { 44 /* Pure upper dir that may contain non pure upper entries */ 45 OVL_IMPURE, 46 /* Non-merge dir that may contain whiteout entries */ 47 OVL_WHITEOUTS, 48 OVL_INDEX, 49 OVL_UPPERDATA, 50 /* Inode number will remain constant over copy up. */ 51 OVL_CONST_INO, 52 }; 53 54 enum ovl_entry_flag { 55 OVL_E_UPPER_ALIAS, 56 OVL_E_OPAQUE, 57 OVL_E_CONNECTED, 58 }; 59 60 enum { 61 OVL_XINO_OFF, 62 OVL_XINO_AUTO, 63 OVL_XINO_ON, 64 }; 65 66 /* 67 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin, 68 * where: 69 * origin.fh - exported file handle of the lower file 70 * origin.uuid - uuid of the lower filesystem 71 */ 72 #define OVL_FH_VERSION 0 73 #define OVL_FH_MAGIC 0xfb 74 75 /* CPU byte order required for fid decoding: */ 76 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0) 77 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1) 78 /* Is the real inode encoded in fid an upper inode? */ 79 #define OVL_FH_FLAG_PATH_UPPER (1 << 2) 80 81 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \ 82 OVL_FH_FLAG_PATH_UPPER) 83 84 #if defined(__LITTLE_ENDIAN) 85 #define OVL_FH_FLAG_CPU_ENDIAN 0 86 #elif defined(__BIG_ENDIAN) 87 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN 88 #else 89 #error Endianness not defined 90 #endif 91 92 /* The type used to be returned by overlay exportfs for misaligned fid */ 93 #define OVL_FILEID_V0 0xfb 94 /* The type returned by overlay exportfs for 32bit aligned fid */ 95 #define OVL_FILEID_V1 0xf8 96 97 /* On-disk format for "origin" file handle */ 98 struct ovl_fb { 99 u8 version; /* 0 */ 100 u8 magic; /* 0xfb */ 101 u8 len; /* size of this header + size of fid */ 102 u8 flags; /* OVL_FH_FLAG_* */ 103 u8 type; /* fid_type of fid */ 104 uuid_t uuid; /* uuid of filesystem */ 105 u32 fid[]; /* file identifier should be 32bit aligned in-memory */ 106 } __packed; 107 108 /* In-memory and on-wire format for overlay file handle */ 109 struct ovl_fh { 110 u8 padding[3]; /* make sure fb.fid is 32bit aligned */ 111 union { 112 struct ovl_fb fb; 113 DECLARE_FLEX_ARRAY(u8, buf); 114 }; 115 } __packed; 116 117 #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb) 118 #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len) 119 #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \ 120 offsetof(struct ovl_fb, fid)) 121 122 extern const char *const ovl_xattr_table[][2]; 123 static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) 124 { 125 return ovl_xattr_table[ox][ofs->config.userxattr]; 126 } 127 128 /* 129 * When changing ownership of an upper object map the intended ownership 130 * according to the upper layer's idmapping. When an upper mount idmaps files 131 * that are stored on-disk as owned by id 1001 to id 1000 this means stat on 132 * this object will report it as being owned by id 1000 when calling stat via 133 * the upper mount. 134 * In order to change ownership of an object so stat reports id 1000 when 135 * called on an idmapped upper mount the value written to disk - i.e., the 136 * value stored in ia_*id - must 1001. The mount mapping helper will thus take 137 * care to map 1000 to 1001. 138 * The mnt idmapping helpers are nops if the upper layer isn't idmapped. 139 */ 140 static inline int ovl_do_notify_change(struct ovl_fs *ofs, 141 struct dentry *upperdentry, 142 struct iattr *attr) 143 { 144 return notify_change(ovl_upper_mnt_userns(ofs), upperdentry, attr, NULL); 145 } 146 147 static inline int ovl_do_rmdir(struct ovl_fs *ofs, 148 struct inode *dir, struct dentry *dentry) 149 { 150 int err = vfs_rmdir(ovl_upper_mnt_userns(ofs), dir, dentry); 151 152 pr_debug("rmdir(%pd2) = %i\n", dentry, err); 153 return err; 154 } 155 156 static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir, 157 struct dentry *dentry) 158 { 159 int err = vfs_unlink(ovl_upper_mnt_userns(ofs), dir, dentry, NULL); 160 161 pr_debug("unlink(%pd2) = %i\n", dentry, err); 162 return err; 163 } 164 165 static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry, 166 struct inode *dir, struct dentry *new_dentry) 167 { 168 int err = vfs_link(old_dentry, ovl_upper_mnt_userns(ofs), dir, new_dentry, NULL); 169 170 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err); 171 return err; 172 } 173 174 static inline int ovl_do_create(struct ovl_fs *ofs, 175 struct inode *dir, struct dentry *dentry, 176 umode_t mode) 177 { 178 int err = vfs_create(ovl_upper_mnt_userns(ofs), dir, dentry, mode, true); 179 180 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); 181 return err; 182 } 183 184 static inline int ovl_do_mkdir(struct ovl_fs *ofs, 185 struct inode *dir, struct dentry *dentry, 186 umode_t mode) 187 { 188 int err = vfs_mkdir(ovl_upper_mnt_userns(ofs), dir, dentry, mode); 189 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err); 190 return err; 191 } 192 193 static inline int ovl_do_mknod(struct ovl_fs *ofs, 194 struct inode *dir, struct dentry *dentry, 195 umode_t mode, dev_t dev) 196 { 197 int err = vfs_mknod(ovl_upper_mnt_userns(ofs), dir, dentry, mode, dev); 198 199 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); 200 return err; 201 } 202 203 static inline int ovl_do_symlink(struct ovl_fs *ofs, 204 struct inode *dir, struct dentry *dentry, 205 const char *oldname) 206 { 207 int err = vfs_symlink(ovl_upper_mnt_userns(ofs), dir, dentry, oldname); 208 209 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); 210 return err; 211 } 212 213 static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, 214 void *value, size_t size) 215 { 216 int err, len; 217 218 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb); 219 220 err = vfs_getxattr(mnt_user_ns(path->mnt), path->dentry, 221 name, value, size); 222 len = (value && err > 0) ? err : 0; 223 224 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", 225 path->dentry, name, min(len, 48), value, size, err); 226 return err; 227 } 228 229 static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, 230 struct dentry *upperdentry, 231 enum ovl_xattr ox, void *value, 232 size_t size) 233 { 234 struct path upperpath = { 235 .dentry = upperdentry, 236 .mnt = ovl_upper_mnt(ofs), 237 }; 238 239 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size); 240 } 241 242 static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, 243 const struct path *path, 244 enum ovl_xattr ox, void *value, 245 size_t size) 246 { 247 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size); 248 } 249 250 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 251 const char *name, const void *value, 252 size_t size, int flags) 253 { 254 int err = vfs_setxattr(ovl_upper_mnt_userns(ofs), dentry, name, 255 value, size, flags); 256 257 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n", 258 dentry, name, min((int)size, 48), value, size, flags, err); 259 return err; 260 } 261 262 static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 263 enum ovl_xattr ox, const void *value, 264 size_t size) 265 { 266 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0); 267 } 268 269 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 270 const char *name) 271 { 272 int err = vfs_removexattr(ovl_upper_mnt_userns(ofs), dentry, name); 273 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); 274 return err; 275 } 276 277 static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 278 enum ovl_xattr ox) 279 { 280 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox)); 281 } 282 283 static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, 284 const char *acl_name, struct posix_acl *acl) 285 { 286 return vfs_set_acl(ovl_upper_mnt_userns(ofs), dentry, acl_name, acl); 287 } 288 289 static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, 290 const char *acl_name) 291 { 292 return vfs_remove_acl(ovl_upper_mnt_userns(ofs), dentry, acl_name); 293 } 294 295 static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir, 296 struct dentry *olddentry, struct inode *newdir, 297 struct dentry *newdentry, unsigned int flags) 298 { 299 int err; 300 struct renamedata rd = { 301 .old_mnt_userns = ovl_upper_mnt_userns(ofs), 302 .old_dir = olddir, 303 .old_dentry = olddentry, 304 .new_mnt_userns = ovl_upper_mnt_userns(ofs), 305 .new_dir = newdir, 306 .new_dentry = newdentry, 307 .flags = flags, 308 }; 309 310 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags); 311 err = vfs_rename(&rd); 312 if (err) { 313 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 314 olddentry, newdentry, err); 315 } 316 return err; 317 } 318 319 static inline int ovl_do_whiteout(struct ovl_fs *ofs, 320 struct inode *dir, struct dentry *dentry) 321 { 322 int err = vfs_whiteout(ovl_upper_mnt_userns(ofs), dir, dentry); 323 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 324 return err; 325 } 326 327 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, 328 struct dentry *dentry, umode_t mode) 329 { 330 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; 331 struct file *file = vfs_tmpfile_open(ovl_upper_mnt_userns(ofs), &path, mode, 332 O_LARGEFILE | O_WRONLY, current_cred()); 333 int err = PTR_ERR_OR_ZERO(file); 334 335 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 336 return file; 337 } 338 339 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, 340 const char *name, 341 struct dentry *base, int len) 342 { 343 return lookup_one(ovl_upper_mnt_userns(ofs), name, base, len); 344 } 345 346 static inline bool ovl_open_flags_need_copy_up(int flags) 347 { 348 if (!flags) 349 return false; 350 351 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 352 } 353 354 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 355 { 356 /* 357 * To avoid regressions in existing setups with overlay lower offline 358 * changes, we allow lower changes only if none of the new features 359 * are used. 360 */ 361 return (!ofs->config.index && !ofs->config.metacopy && 362 !ofs->config.redirect_dir && ofs->config.xino != OVL_XINO_ON); 363 } 364 365 366 /* util.c */ 367 int ovl_want_write(struct dentry *dentry); 368 void ovl_drop_write(struct dentry *dentry); 369 struct dentry *ovl_workdir(struct dentry *dentry); 370 const struct cred *ovl_override_creds(struct super_block *sb); 371 int ovl_can_decode_fh(struct super_block *sb); 372 struct dentry *ovl_indexdir(struct super_block *sb); 373 bool ovl_index_all(struct super_block *sb); 374 bool ovl_verify_lower(struct super_block *sb); 375 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 376 bool ovl_dentry_remote(struct dentry *dentry); 377 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry, 378 unsigned int mask); 379 bool ovl_dentry_weird(struct dentry *dentry); 380 enum ovl_path_type ovl_path_type(struct dentry *dentry); 381 void ovl_path_upper(struct dentry *dentry, struct path *path); 382 void ovl_path_lower(struct dentry *dentry, struct path *path); 383 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 384 void ovl_i_path_real(struct inode *inode, struct path *path); 385 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 386 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); 387 struct dentry *ovl_dentry_upper(struct dentry *dentry); 388 struct dentry *ovl_dentry_lower(struct dentry *dentry); 389 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 390 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); 391 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 392 struct dentry *ovl_dentry_real(struct dentry *dentry); 393 struct dentry *ovl_i_dentry_upper(struct inode *inode); 394 struct inode *ovl_inode_upper(struct inode *inode); 395 struct inode *ovl_inode_lower(struct inode *inode); 396 struct inode *ovl_inode_lowerdata(struct inode *inode); 397 struct inode *ovl_inode_real(struct inode *inode); 398 struct inode *ovl_inode_realdata(struct inode *inode); 399 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 400 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 401 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 402 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 403 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 404 bool ovl_dentry_is_opaque(struct dentry *dentry); 405 bool ovl_dentry_is_whiteout(struct dentry *dentry); 406 void ovl_dentry_set_opaque(struct dentry *dentry); 407 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 408 void ovl_dentry_set_upper_alias(struct dentry *dentry); 409 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 410 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 411 bool ovl_has_upperdata(struct inode *inode); 412 void ovl_set_upperdata(struct inode *inode); 413 bool ovl_redirect_dir(struct super_block *sb); 414 const char *ovl_dentry_get_redirect(struct dentry *dentry); 415 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 416 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 417 void ovl_dir_modified(struct dentry *dentry, bool impurity); 418 u64 ovl_inode_version_get(struct inode *inode); 419 bool ovl_is_whiteout(struct dentry *dentry); 420 struct file *ovl_path_open(const struct path *path, int flags); 421 int ovl_copy_up_start(struct dentry *dentry, int flags); 422 void ovl_copy_up_end(struct dentry *dentry); 423 bool ovl_already_copied_up(struct dentry *dentry, int flags); 424 bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, 425 enum ovl_xattr ox); 426 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); 427 428 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, 429 struct dentry *upperdentry) 430 { 431 struct path upperpath = { 432 .dentry = upperdentry, 433 .mnt = ovl_upper_mnt(ofs), 434 }; 435 return ovl_path_check_origin_xattr(ofs, &upperpath); 436 } 437 438 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 439 enum ovl_xattr ox, const void *value, size_t size, 440 int xerr); 441 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 442 bool ovl_inuse_trylock(struct dentry *dentry); 443 void ovl_inuse_unlock(struct dentry *dentry); 444 bool ovl_is_inuse(struct dentry *dentry); 445 bool ovl_need_index(struct dentry *dentry); 446 int ovl_nlink_start(struct dentry *dentry); 447 void ovl_nlink_end(struct dentry *dentry); 448 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); 449 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path); 450 bool ovl_is_metacopy_dentry(struct dentry *dentry); 451 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); 452 int ovl_sync_status(struct ovl_fs *ofs); 453 454 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 455 { 456 set_bit(flag, &OVL_I(inode)->flags); 457 } 458 459 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 460 { 461 clear_bit(flag, &OVL_I(inode)->flags); 462 } 463 464 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 465 { 466 return test_bit(flag, &OVL_I(inode)->flags); 467 } 468 469 static inline bool ovl_is_impuredir(struct super_block *sb, 470 struct dentry *upperdentry) 471 { 472 struct ovl_fs *ofs = OVL_FS(sb); 473 struct path upperpath = { 474 .dentry = upperdentry, 475 .mnt = ovl_upper_mnt(ofs), 476 }; 477 478 return ovl_path_check_dir_xattr(ofs, &upperpath, OVL_XATTR_IMPURE); 479 } 480 481 /* 482 * With xino=auto, we do best effort to keep all inodes on same st_dev and 483 * d_ino consistent with st_ino. 484 * With xino=on, we do the same effort but we warn if we failed. 485 */ 486 static inline bool ovl_xino_warn(struct super_block *sb) 487 { 488 return OVL_FS(sb)->config.xino == OVL_XINO_ON; 489 } 490 491 /* All layers on same fs? */ 492 static inline bool ovl_same_fs(struct super_block *sb) 493 { 494 return OVL_FS(sb)->xino_mode == 0; 495 } 496 497 /* All overlay inodes have same st_dev? */ 498 static inline bool ovl_same_dev(struct super_block *sb) 499 { 500 return OVL_FS(sb)->xino_mode >= 0; 501 } 502 503 static inline unsigned int ovl_xino_bits(struct super_block *sb) 504 { 505 return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0; 506 } 507 508 static inline void ovl_inode_lock(struct inode *inode) 509 { 510 mutex_lock(&OVL_I(inode)->lock); 511 } 512 513 static inline int ovl_inode_lock_interruptible(struct inode *inode) 514 { 515 return mutex_lock_interruptible(&OVL_I(inode)->lock); 516 } 517 518 static inline void ovl_inode_unlock(struct inode *inode) 519 { 520 mutex_unlock(&OVL_I(inode)->lock); 521 } 522 523 524 /* namei.c */ 525 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 526 527 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 528 { 529 if (fh_len < sizeof(struct ovl_fh)) 530 return -EINVAL; 531 532 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 533 } 534 535 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 536 struct vfsmount *mnt, bool connected); 537 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 538 struct dentry *upperdentry, struct ovl_path **stackp); 539 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 540 enum ovl_xattr ox, struct dentry *real, bool is_upper, 541 bool set); 542 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, 543 bool connected); 544 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 545 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 546 struct qstr *name); 547 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 548 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 549 struct dentry *origin, bool verify); 550 int ovl_path_next(int idx, struct dentry *dentry, struct path *path); 551 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 552 unsigned int flags); 553 bool ovl_lower_positive(struct dentry *dentry); 554 555 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 556 struct dentry *origin, bool set) 557 { 558 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, origin, 559 false, set); 560 } 561 562 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 563 struct dentry *upper, bool set) 564 { 565 return ovl_verify_set_fh(ofs, index, OVL_XATTR_UPPER, upper, true, set); 566 } 567 568 /* readdir.c */ 569 extern const struct file_operations ovl_dir_operations; 570 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 571 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 572 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 573 struct list_head *list); 574 void ovl_cache_free(struct list_head *list); 575 void ovl_dir_cache_free(struct inode *inode); 576 int ovl_check_d_type_supported(const struct path *realpath); 577 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir, 578 struct vfsmount *mnt, struct dentry *dentry, int level); 579 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 580 581 /* 582 * Can we iterate real dir directly? 583 * 584 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 585 * lower dir was removed under it and possibly before it was rotated from upper 586 * to lower layer. 587 */ 588 static inline bool ovl_dir_is_real(struct inode *dir) 589 { 590 return !ovl_test_flag(OVL_WHITEOUTS, dir); 591 } 592 593 /* inode.c */ 594 int ovl_set_nlink_upper(struct dentry *dentry); 595 int ovl_set_nlink_lower(struct dentry *dentry); 596 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 597 struct dentry *upperdentry, 598 unsigned int fallback); 599 int ovl_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, 600 struct iattr *attr); 601 int ovl_getattr(struct user_namespace *mnt_userns, const struct path *path, 602 struct kstat *stat, u32 request_mask, unsigned int flags); 603 int ovl_permission(struct user_namespace *mnt_userns, struct inode *inode, 604 int mask); 605 int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name, 606 const void *value, size_t size, int flags); 607 int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, 608 void *value, size_t size); 609 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 610 611 #ifdef CONFIG_FS_POSIX_ACL 612 struct posix_acl *do_ovl_get_acl(struct user_namespace *mnt_userns, 613 struct inode *inode, int type, 614 bool rcu, bool noperm); 615 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, 616 bool rcu) 617 { 618 return do_ovl_get_acl(&init_user_ns, inode, type, rcu, true); 619 } 620 static inline struct posix_acl *ovl_get_acl(struct user_namespace *mnt_userns, 621 struct dentry *dentry, int type) 622 { 623 return do_ovl_get_acl(mnt_userns, d_inode(dentry), type, false, false); 624 } 625 int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, 626 struct posix_acl *acl, int type); 627 struct posix_acl *ovl_get_acl_path(const struct path *path, 628 const char *acl_name, bool noperm); 629 #else 630 #define ovl_get_inode_acl NULL 631 #define ovl_get_acl NULL 632 #define ovl_set_acl NULL 633 static inline struct posix_acl *ovl_get_acl_path(const struct path *path, 634 const char *acl_name, 635 bool noperm) 636 { 637 return NULL; 638 } 639 #endif 640 641 int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags); 642 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 643 644 struct ovl_inode_params { 645 struct inode *newinode; 646 struct dentry *upperdentry; 647 struct ovl_path *lowerpath; 648 bool index; 649 unsigned int numlower; 650 char *redirect; 651 struct dentry *lowerdata; 652 }; 653 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 654 unsigned long ino, int fsid); 655 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 656 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 657 bool is_upper); 658 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 659 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 660 struct inode *ovl_get_inode(struct super_block *sb, 661 struct ovl_inode_params *oip); 662 void ovl_copyattr(struct inode *to); 663 664 /* vfs inode flags copied from real to ovl inode */ 665 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE) 666 /* vfs inode flags read from overlay.protattr xattr to ovl inode */ 667 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 668 669 /* 670 * fileattr flags copied from lower to upper inode on copy up. 671 * We cannot copy up immutable/append-only flags, because that would prevent 672 * linking temp inode to upper dir, so we store them in xattr instead. 673 */ 674 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 675 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 676 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 677 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 678 679 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 680 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 681 struct fileattr *fa); 682 683 static inline void ovl_copyflags(struct inode *from, struct inode *to) 684 { 685 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 686 687 inode_set_flags(to, from->i_flags & mask, mask); 688 } 689 690 /* dir.c */ 691 extern const struct inode_operations ovl_dir_inode_operations; 692 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, 693 struct dentry *dentry); 694 struct ovl_cattr { 695 dev_t rdev; 696 umode_t mode; 697 const char *link; 698 struct dentry *hardlink; 699 }; 700 701 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 702 703 int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, 704 struct dentry **newdentry, umode_t mode); 705 struct dentry *ovl_create_real(struct ovl_fs *ofs, 706 struct inode *dir, struct dentry *newdentry, 707 struct ovl_cattr *attr); 708 int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); 709 struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); 710 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, 711 struct ovl_cattr *attr); 712 713 /* file.c */ 714 extern const struct file_operations ovl_file_operations; 715 int __init ovl_aio_request_cache_init(void); 716 void ovl_aio_request_cache_destroy(void); 717 int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa); 718 int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa); 719 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); 720 int ovl_fileattr_set(struct user_namespace *mnt_userns, 721 struct dentry *dentry, struct fileattr *fa); 722 723 /* copy_up.c */ 724 int ovl_copy_up(struct dentry *dentry); 725 int ovl_copy_up_with_data(struct dentry *dentry); 726 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 727 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); 728 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); 729 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, 730 bool is_upper); 731 int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower, 732 struct dentry *upper); 733 734 /* export.c */ 735 extern const struct export_operations ovl_export_operations; 736