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_REDIRECT_OFF, /* "off" mode is never used. In effect */ 62 OVL_REDIRECT_FOLLOW, /* ...it translates to either "follow" */ 63 OVL_REDIRECT_NOFOLLOW, /* ...or "nofollow". */ 64 OVL_REDIRECT_ON, 65 }; 66 67 enum { 68 OVL_XINO_OFF, 69 OVL_XINO_AUTO, 70 OVL_XINO_ON, 71 }; 72 73 /* The set of options that user requested explicitly via mount options */ 74 struct ovl_opt_set { 75 bool metacopy; 76 bool redirect; 77 bool nfs_export; 78 bool index; 79 }; 80 81 /* 82 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin, 83 * where: 84 * origin.fh - exported file handle of the lower file 85 * origin.uuid - uuid of the lower filesystem 86 */ 87 #define OVL_FH_VERSION 0 88 #define OVL_FH_MAGIC 0xfb 89 90 /* CPU byte order required for fid decoding: */ 91 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0) 92 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1) 93 /* Is the real inode encoded in fid an upper inode? */ 94 #define OVL_FH_FLAG_PATH_UPPER (1 << 2) 95 96 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \ 97 OVL_FH_FLAG_PATH_UPPER) 98 99 #if defined(__LITTLE_ENDIAN) 100 #define OVL_FH_FLAG_CPU_ENDIAN 0 101 #elif defined(__BIG_ENDIAN) 102 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN 103 #else 104 #error Endianness not defined 105 #endif 106 107 /* The type used to be returned by overlay exportfs for misaligned fid */ 108 #define OVL_FILEID_V0 0xfb 109 /* The type returned by overlay exportfs for 32bit aligned fid */ 110 #define OVL_FILEID_V1 0xf8 111 112 /* On-disk format for "origin" file handle */ 113 struct ovl_fb { 114 u8 version; /* 0 */ 115 u8 magic; /* 0xfb */ 116 u8 len; /* size of this header + size of fid */ 117 u8 flags; /* OVL_FH_FLAG_* */ 118 u8 type; /* fid_type of fid */ 119 uuid_t uuid; /* uuid of filesystem */ 120 u32 fid[]; /* file identifier should be 32bit aligned in-memory */ 121 } __packed; 122 123 /* In-memory and on-wire format for overlay file handle */ 124 struct ovl_fh { 125 u8 padding[3]; /* make sure fb.fid is 32bit aligned */ 126 union { 127 struct ovl_fb fb; 128 DECLARE_FLEX_ARRAY(u8, buf); 129 }; 130 } __packed; 131 132 #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb) 133 #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len) 134 #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \ 135 offsetof(struct ovl_fb, fid)) 136 137 extern const char *const ovl_xattr_table[][2]; 138 static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) 139 { 140 return ovl_xattr_table[ox][ofs->config.userxattr]; 141 } 142 143 /* 144 * When changing ownership of an upper object map the intended ownership 145 * according to the upper layer's idmapping. When an upper mount idmaps files 146 * that are stored on-disk as owned by id 1001 to id 1000 this means stat on 147 * this object will report it as being owned by id 1000 when calling stat via 148 * the upper mount. 149 * In order to change ownership of an object so stat reports id 1000 when 150 * called on an idmapped upper mount the value written to disk - i.e., the 151 * value stored in ia_*id - must 1001. The mount mapping helper will thus take 152 * care to map 1000 to 1001. 153 * The mnt idmapping helpers are nops if the upper layer isn't idmapped. 154 */ 155 static inline int ovl_do_notify_change(struct ovl_fs *ofs, 156 struct dentry *upperdentry, 157 struct iattr *attr) 158 { 159 return notify_change(ovl_upper_mnt_idmap(ofs), upperdentry, attr, NULL); 160 } 161 162 static inline int ovl_do_rmdir(struct ovl_fs *ofs, 163 struct inode *dir, struct dentry *dentry) 164 { 165 int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry); 166 167 pr_debug("rmdir(%pd2) = %i\n", dentry, err); 168 return err; 169 } 170 171 static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir, 172 struct dentry *dentry) 173 { 174 int err = vfs_unlink(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL); 175 176 pr_debug("unlink(%pd2) = %i\n", dentry, err); 177 return err; 178 } 179 180 static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry, 181 struct inode *dir, struct dentry *new_dentry) 182 { 183 int err = vfs_link(old_dentry, ovl_upper_mnt_idmap(ofs), dir, 184 new_dentry, NULL); 185 186 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err); 187 return err; 188 } 189 190 static inline int ovl_do_create(struct ovl_fs *ofs, 191 struct inode *dir, struct dentry *dentry, 192 umode_t mode) 193 { 194 int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true); 195 196 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); 197 return err; 198 } 199 200 static inline int ovl_do_mkdir(struct ovl_fs *ofs, 201 struct inode *dir, struct dentry *dentry, 202 umode_t mode) 203 { 204 int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode); 205 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err); 206 return err; 207 } 208 209 static inline int ovl_do_mknod(struct ovl_fs *ofs, 210 struct inode *dir, struct dentry *dentry, 211 umode_t mode, dev_t dev) 212 { 213 int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev); 214 215 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); 216 return err; 217 } 218 219 static inline int ovl_do_symlink(struct ovl_fs *ofs, 220 struct inode *dir, struct dentry *dentry, 221 const char *oldname) 222 { 223 int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname); 224 225 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); 226 return err; 227 } 228 229 static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, 230 void *value, size_t size) 231 { 232 int err, len; 233 234 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb); 235 236 err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry, 237 name, value, size); 238 len = (value && err > 0) ? err : 0; 239 240 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", 241 path->dentry, name, min(len, 48), value, size, err); 242 return err; 243 } 244 245 static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, 246 struct dentry *upperdentry, 247 enum ovl_xattr ox, void *value, 248 size_t size) 249 { 250 struct path upperpath = { 251 .dentry = upperdentry, 252 .mnt = ovl_upper_mnt(ofs), 253 }; 254 255 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size); 256 } 257 258 static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, 259 const struct path *path, 260 enum ovl_xattr ox, void *value, 261 size_t size) 262 { 263 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size); 264 } 265 266 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 267 const char *name, const void *value, 268 size_t size, int flags) 269 { 270 int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name, 271 value, size, flags); 272 273 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n", 274 dentry, name, min((int)size, 48), value, size, flags, err); 275 return err; 276 } 277 278 static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 279 enum ovl_xattr ox, const void *value, 280 size_t size) 281 { 282 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0); 283 } 284 285 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 286 const char *name) 287 { 288 int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name); 289 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); 290 return err; 291 } 292 293 static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 294 enum ovl_xattr ox) 295 { 296 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox)); 297 } 298 299 static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, 300 const char *acl_name, struct posix_acl *acl) 301 { 302 return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl); 303 } 304 305 static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, 306 const char *acl_name) 307 { 308 return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name); 309 } 310 311 static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir, 312 struct dentry *olddentry, struct inode *newdir, 313 struct dentry *newdentry, unsigned int flags) 314 { 315 int err; 316 struct renamedata rd = { 317 .old_mnt_idmap = ovl_upper_mnt_idmap(ofs), 318 .old_dir = olddir, 319 .old_dentry = olddentry, 320 .new_mnt_idmap = ovl_upper_mnt_idmap(ofs), 321 .new_dir = newdir, 322 .new_dentry = newdentry, 323 .flags = flags, 324 }; 325 326 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags); 327 err = vfs_rename(&rd); 328 if (err) { 329 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 330 olddentry, newdentry, err); 331 } 332 return err; 333 } 334 335 static inline int ovl_do_whiteout(struct ovl_fs *ofs, 336 struct inode *dir, struct dentry *dentry) 337 { 338 int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry); 339 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 340 return err; 341 } 342 343 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, 344 struct dentry *dentry, umode_t mode) 345 { 346 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; 347 struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, 348 mode, O_LARGEFILE | O_WRONLY, 349 current_cred()); 350 int err = PTR_ERR_OR_ZERO(file); 351 352 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 353 return file; 354 } 355 356 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, 357 const char *name, 358 struct dentry *base, int len) 359 { 360 return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len); 361 } 362 363 static inline bool ovl_open_flags_need_copy_up(int flags) 364 { 365 if (!flags) 366 return false; 367 368 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 369 } 370 371 372 /* params.c */ 373 #define OVL_MAX_STACK 500 374 375 struct ovl_fs_context_layer { 376 char *name; 377 struct path path; 378 }; 379 380 struct ovl_fs_context { 381 struct path upper; 382 struct path work; 383 size_t capacity; 384 size_t nr; /* includes nr_data */ 385 size_t nr_data; 386 struct ovl_opt_set set; 387 struct ovl_fs_context_layer *lower; 388 }; 389 390 int ovl_parse_param_upperdir(const char *name, struct fs_context *fc, 391 bool workdir); 392 int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc); 393 void ovl_parse_param_drop_lowerdir(struct ovl_fs_context *ctx); 394 395 /* util.c */ 396 int ovl_want_write(struct dentry *dentry); 397 void ovl_drop_write(struct dentry *dentry); 398 struct dentry *ovl_workdir(struct dentry *dentry); 399 const struct cred *ovl_override_creds(struct super_block *sb); 400 int ovl_can_decode_fh(struct super_block *sb); 401 struct dentry *ovl_indexdir(struct super_block *sb); 402 bool ovl_index_all(struct super_block *sb); 403 bool ovl_verify_lower(struct super_block *sb); 404 struct ovl_path *ovl_stack_alloc(unsigned int n); 405 void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); 406 void ovl_stack_put(struct ovl_path *stack, unsigned int n); 407 void ovl_stack_free(struct ovl_path *stack, unsigned int n); 408 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 409 void ovl_free_entry(struct ovl_entry *oe); 410 bool ovl_dentry_remote(struct dentry *dentry); 411 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); 412 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, 413 struct ovl_entry *oe); 414 void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, 415 struct ovl_entry *oe, unsigned int mask); 416 bool ovl_dentry_weird(struct dentry *dentry); 417 enum ovl_path_type ovl_path_type(struct dentry *dentry); 418 void ovl_path_upper(struct dentry *dentry, struct path *path); 419 void ovl_path_lower(struct dentry *dentry, struct path *path); 420 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 421 struct inode *ovl_i_path_real(struct inode *inode, struct path *path); 422 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 423 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); 424 struct dentry *ovl_dentry_upper(struct dentry *dentry); 425 struct dentry *ovl_dentry_lower(struct dentry *dentry); 426 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 427 int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); 428 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); 429 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 430 struct dentry *ovl_dentry_real(struct dentry *dentry); 431 struct dentry *ovl_i_dentry_upper(struct inode *inode); 432 struct inode *ovl_inode_upper(struct inode *inode); 433 struct inode *ovl_inode_lower(struct inode *inode); 434 struct inode *ovl_inode_lowerdata(struct inode *inode); 435 struct inode *ovl_inode_real(struct inode *inode); 436 struct inode *ovl_inode_realdata(struct inode *inode); 437 const char *ovl_lowerdata_redirect(struct inode *inode); 438 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 439 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 440 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 441 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 442 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 443 bool ovl_dentry_is_opaque(struct dentry *dentry); 444 bool ovl_dentry_is_whiteout(struct dentry *dentry); 445 void ovl_dentry_set_opaque(struct dentry *dentry); 446 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 447 void ovl_dentry_set_upper_alias(struct dentry *dentry); 448 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 449 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 450 bool ovl_has_upperdata(struct inode *inode); 451 void ovl_set_upperdata(struct inode *inode); 452 const char *ovl_dentry_get_redirect(struct dentry *dentry); 453 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 454 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 455 void ovl_dir_modified(struct dentry *dentry, bool impurity); 456 u64 ovl_inode_version_get(struct inode *inode); 457 bool ovl_is_whiteout(struct dentry *dentry); 458 struct file *ovl_path_open(const struct path *path, int flags); 459 int ovl_copy_up_start(struct dentry *dentry, int flags); 460 void ovl_copy_up_end(struct dentry *dentry); 461 bool ovl_already_copied_up(struct dentry *dentry, int flags); 462 bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, 463 enum ovl_xattr ox); 464 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); 465 466 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, 467 struct dentry *upperdentry) 468 { 469 struct path upperpath = { 470 .dentry = upperdentry, 471 .mnt = ovl_upper_mnt(ofs), 472 }; 473 return ovl_path_check_origin_xattr(ofs, &upperpath); 474 } 475 476 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 477 enum ovl_xattr ox, const void *value, size_t size, 478 int xerr); 479 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 480 bool ovl_inuse_trylock(struct dentry *dentry); 481 void ovl_inuse_unlock(struct dentry *dentry); 482 bool ovl_is_inuse(struct dentry *dentry); 483 bool ovl_need_index(struct dentry *dentry); 484 int ovl_nlink_start(struct dentry *dentry); 485 void ovl_nlink_end(struct dentry *dentry); 486 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); 487 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path); 488 bool ovl_is_metacopy_dentry(struct dentry *dentry); 489 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); 490 int ovl_sync_status(struct ovl_fs *ofs); 491 492 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 493 { 494 set_bit(flag, &OVL_I(inode)->flags); 495 } 496 497 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 498 { 499 clear_bit(flag, &OVL_I(inode)->flags); 500 } 501 502 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 503 { 504 return test_bit(flag, &OVL_I(inode)->flags); 505 } 506 507 static inline bool ovl_is_impuredir(struct super_block *sb, 508 struct dentry *upperdentry) 509 { 510 struct ovl_fs *ofs = OVL_FS(sb); 511 struct path upperpath = { 512 .dentry = upperdentry, 513 .mnt = ovl_upper_mnt(ofs), 514 }; 515 516 return ovl_path_check_dir_xattr(ofs, &upperpath, OVL_XATTR_IMPURE); 517 } 518 519 static inline bool ovl_redirect_follow(struct ovl_fs *ofs) 520 { 521 return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW; 522 } 523 524 static inline bool ovl_redirect_dir(struct ovl_fs *ofs) 525 { 526 return ofs->config.redirect_mode == OVL_REDIRECT_ON; 527 } 528 529 /* 530 * With xino=auto, we do best effort to keep all inodes on same st_dev and 531 * d_ino consistent with st_ino. 532 * With xino=on, we do the same effort but we warn if we failed. 533 */ 534 static inline bool ovl_xino_warn(struct ovl_fs *ofs) 535 { 536 return ofs->config.xino == OVL_XINO_ON; 537 } 538 539 /* 540 * To avoid regressions in existing setups with overlay lower offline changes, 541 * we allow lower changes only if none of the new features are used. 542 */ 543 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 544 { 545 return (!ofs->config.index && !ofs->config.metacopy && 546 !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs)); 547 } 548 549 /* All layers on same fs? */ 550 static inline bool ovl_same_fs(struct ovl_fs *ofs) 551 { 552 return ofs->xino_mode == 0; 553 } 554 555 /* All overlay inodes have same st_dev? */ 556 static inline bool ovl_same_dev(struct ovl_fs *ofs) 557 { 558 return ofs->xino_mode >= 0; 559 } 560 561 static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) 562 { 563 return ovl_same_dev(ofs) ? ofs->xino_mode : 0; 564 } 565 566 static inline void ovl_inode_lock(struct inode *inode) 567 { 568 mutex_lock(&OVL_I(inode)->lock); 569 } 570 571 static inline int ovl_inode_lock_interruptible(struct inode *inode) 572 { 573 return mutex_lock_interruptible(&OVL_I(inode)->lock); 574 } 575 576 static inline void ovl_inode_unlock(struct inode *inode) 577 { 578 mutex_unlock(&OVL_I(inode)->lock); 579 } 580 581 582 /* namei.c */ 583 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 584 585 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 586 { 587 if (fh_len < sizeof(struct ovl_fh)) 588 return -EINVAL; 589 590 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 591 } 592 593 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 594 struct vfsmount *mnt, bool connected); 595 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 596 struct dentry *upperdentry, struct ovl_path **stackp); 597 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 598 enum ovl_xattr ox, struct dentry *real, bool is_upper, 599 bool set); 600 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, 601 bool connected); 602 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 603 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 604 struct qstr *name); 605 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 606 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 607 struct dentry *origin, bool verify); 608 int ovl_path_next(int idx, struct dentry *dentry, struct path *path); 609 int ovl_maybe_lookup_lowerdata(struct dentry *dentry); 610 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 611 unsigned int flags); 612 bool ovl_lower_positive(struct dentry *dentry); 613 614 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 615 struct dentry *origin, bool set) 616 { 617 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, origin, 618 false, set); 619 } 620 621 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 622 struct dentry *upper, bool set) 623 { 624 return ovl_verify_set_fh(ofs, index, OVL_XATTR_UPPER, upper, true, set); 625 } 626 627 /* readdir.c */ 628 extern const struct file_operations ovl_dir_operations; 629 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 630 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 631 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 632 struct list_head *list); 633 void ovl_cache_free(struct list_head *list); 634 void ovl_dir_cache_free(struct inode *inode); 635 int ovl_check_d_type_supported(const struct path *realpath); 636 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir, 637 struct vfsmount *mnt, struct dentry *dentry, int level); 638 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 639 640 /* 641 * Can we iterate real dir directly? 642 * 643 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 644 * lower dir was removed under it and possibly before it was rotated from upper 645 * to lower layer. 646 */ 647 static inline bool ovl_dir_is_real(struct inode *dir) 648 { 649 return !ovl_test_flag(OVL_WHITEOUTS, dir); 650 } 651 652 /* inode.c */ 653 int ovl_set_nlink_upper(struct dentry *dentry); 654 int ovl_set_nlink_lower(struct dentry *dentry); 655 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 656 struct dentry *upperdentry, 657 unsigned int fallback); 658 int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 659 struct iattr *attr); 660 int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, 661 struct kstat *stat, u32 request_mask, unsigned int flags); 662 int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, 663 int mask); 664 int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name, 665 const void *value, size_t size, int flags); 666 int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, 667 void *value, size_t size); 668 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 669 670 #ifdef CONFIG_FS_POSIX_ACL 671 struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, 672 struct inode *inode, int type, 673 bool rcu, bool noperm); 674 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, 675 bool rcu) 676 { 677 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true); 678 } 679 static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, 680 struct dentry *dentry, int type) 681 { 682 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false); 683 } 684 int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 685 struct posix_acl *acl, int type); 686 struct posix_acl *ovl_get_acl_path(const struct path *path, 687 const char *acl_name, bool noperm); 688 #else 689 #define ovl_get_inode_acl NULL 690 #define ovl_get_acl NULL 691 #define ovl_set_acl NULL 692 static inline struct posix_acl *ovl_get_acl_path(const struct path *path, 693 const char *acl_name, 694 bool noperm) 695 { 696 return NULL; 697 } 698 #endif 699 700 int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags); 701 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 702 703 struct ovl_inode_params { 704 struct inode *newinode; 705 struct dentry *upperdentry; 706 struct ovl_entry *oe; 707 bool index; 708 char *redirect; 709 char *lowerdata_redirect; 710 }; 711 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 712 unsigned long ino, int fsid); 713 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 714 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 715 bool is_upper); 716 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 717 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 718 struct inode *ovl_get_inode(struct super_block *sb, 719 struct ovl_inode_params *oip); 720 void ovl_copyattr(struct inode *to); 721 722 /* vfs inode flags copied from real to ovl inode */ 723 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE) 724 /* vfs inode flags read from overlay.protattr xattr to ovl inode */ 725 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 726 727 /* 728 * fileattr flags copied from lower to upper inode on copy up. 729 * We cannot copy up immutable/append-only flags, because that would prevent 730 * linking temp inode to upper dir, so we store them in xattr instead. 731 */ 732 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 733 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 734 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 735 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 736 737 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 738 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 739 struct fileattr *fa); 740 741 static inline void ovl_copyflags(struct inode *from, struct inode *to) 742 { 743 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 744 745 inode_set_flags(to, from->i_flags & mask, mask); 746 } 747 748 /* dir.c */ 749 extern const struct inode_operations ovl_dir_inode_operations; 750 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, 751 struct dentry *dentry); 752 struct ovl_cattr { 753 dev_t rdev; 754 umode_t mode; 755 const char *link; 756 struct dentry *hardlink; 757 }; 758 759 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 760 761 int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, 762 struct dentry **newdentry, umode_t mode); 763 struct dentry *ovl_create_real(struct ovl_fs *ofs, 764 struct inode *dir, struct dentry *newdentry, 765 struct ovl_cattr *attr); 766 int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); 767 struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); 768 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, 769 struct ovl_cattr *attr); 770 771 /* file.c */ 772 extern const struct file_operations ovl_file_operations; 773 int __init ovl_aio_request_cache_init(void); 774 void ovl_aio_request_cache_destroy(void); 775 int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa); 776 int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa); 777 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); 778 int ovl_fileattr_set(struct mnt_idmap *idmap, 779 struct dentry *dentry, struct fileattr *fa); 780 781 /* copy_up.c */ 782 int ovl_copy_up(struct dentry *dentry); 783 int ovl_copy_up_with_data(struct dentry *dentry); 784 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 785 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); 786 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); 787 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, 788 bool is_upper); 789 int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower, 790 struct dentry *upper); 791 792 /* export.c */ 793 extern const struct export_operations ovl_export_operations; 794