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/fsverity.h> 11 #include <linux/namei.h> 12 #include <linux/posix_acl.h> 13 #include <linux/posix_acl_xattr.h> 14 #include "ovl_entry.h" 15 16 #undef pr_fmt 17 #define pr_fmt(fmt) "overlayfs: " fmt 18 19 enum ovl_path_type { 20 __OVL_PATH_UPPER = (1 << 0), 21 __OVL_PATH_MERGE = (1 << 1), 22 __OVL_PATH_ORIGIN = (1 << 2), 23 }; 24 25 #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER) 26 #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE) 27 #define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN) 28 29 #define OVL_XATTR_NAMESPACE "overlay." 30 #define OVL_XATTR_TRUSTED_PREFIX XATTR_TRUSTED_PREFIX OVL_XATTR_NAMESPACE 31 #define OVL_XATTR_TRUSTED_PREFIX_LEN (sizeof(OVL_XATTR_TRUSTED_PREFIX) - 1) 32 #define OVL_XATTR_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE 33 #define OVL_XATTR_USER_PREFIX_LEN (sizeof(OVL_XATTR_USER_PREFIX) - 1) 34 35 #define OVL_XATTR_ESCAPE_PREFIX OVL_XATTR_NAMESPACE 36 #define OVL_XATTR_ESCAPE_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_PREFIX) - 1) 37 #define OVL_XATTR_ESCAPE_TRUSTED_PREFIX OVL_XATTR_TRUSTED_PREFIX OVL_XATTR_ESCAPE_PREFIX 38 #define OVL_XATTR_ESCAPE_TRUSTED_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_TRUSTED_PREFIX) - 1) 39 #define OVL_XATTR_ESCAPE_USER_PREFIX OVL_XATTR_USER_PREFIX OVL_XATTR_ESCAPE_PREFIX 40 #define OVL_XATTR_ESCAPE_USER_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_USER_PREFIX) - 1) 41 42 enum ovl_xattr { 43 OVL_XATTR_OPAQUE, 44 OVL_XATTR_REDIRECT, 45 OVL_XATTR_ORIGIN, 46 OVL_XATTR_IMPURE, 47 OVL_XATTR_NLINK, 48 OVL_XATTR_UPPER, 49 OVL_XATTR_UUID, 50 OVL_XATTR_METACOPY, 51 OVL_XATTR_PROTATTR, 52 OVL_XATTR_XWHITEOUT, 53 }; 54 55 enum ovl_inode_flag { 56 /* Pure upper dir that may contain non pure upper entries */ 57 OVL_IMPURE, 58 /* Non-merge dir that may contain whiteout entries */ 59 OVL_WHITEOUTS, 60 OVL_INDEX, 61 OVL_UPPERDATA, 62 /* Inode number will remain constant over copy up. */ 63 OVL_CONST_INO, 64 OVL_HAS_DIGEST, 65 OVL_VERIFIED_DIGEST, 66 }; 67 68 enum ovl_entry_flag { 69 OVL_E_UPPER_ALIAS, 70 OVL_E_OPAQUE, 71 OVL_E_CONNECTED, 72 /* Lower stack may contain xwhiteout entries */ 73 OVL_E_XWHITEOUTS, 74 }; 75 76 enum { 77 OVL_REDIRECT_OFF, /* "off" mode is never used. In effect */ 78 OVL_REDIRECT_FOLLOW, /* ...it translates to either "follow" */ 79 OVL_REDIRECT_NOFOLLOW, /* ...or "nofollow". */ 80 OVL_REDIRECT_ON, 81 }; 82 83 enum { 84 OVL_UUID_OFF, 85 OVL_UUID_NULL, 86 OVL_UUID_AUTO, 87 OVL_UUID_ON, 88 }; 89 90 enum { 91 OVL_XINO_OFF, 92 OVL_XINO_AUTO, 93 OVL_XINO_ON, 94 }; 95 96 enum { 97 OVL_VERITY_OFF, 98 OVL_VERITY_ON, 99 OVL_VERITY_REQUIRE, 100 }; 101 102 /* 103 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin, 104 * where: 105 * origin.fh - exported file handle of the lower file 106 * origin.uuid - uuid of the lower filesystem 107 */ 108 #define OVL_FH_VERSION 0 109 #define OVL_FH_MAGIC 0xfb 110 111 /* CPU byte order required for fid decoding: */ 112 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0) 113 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1) 114 /* Is the real inode encoded in fid an upper inode? */ 115 #define OVL_FH_FLAG_PATH_UPPER (1 << 2) 116 117 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \ 118 OVL_FH_FLAG_PATH_UPPER) 119 120 #if defined(__LITTLE_ENDIAN) 121 #define OVL_FH_FLAG_CPU_ENDIAN 0 122 #elif defined(__BIG_ENDIAN) 123 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN 124 #else 125 #error Endianness not defined 126 #endif 127 128 /* The type used to be returned by overlay exportfs for misaligned fid */ 129 #define OVL_FILEID_V0 0xfb 130 /* The type returned by overlay exportfs for 32bit aligned fid */ 131 #define OVL_FILEID_V1 0xf8 132 133 /* On-disk format for "origin" file handle */ 134 struct ovl_fb { 135 u8 version; /* 0 */ 136 u8 magic; /* 0xfb */ 137 u8 len; /* size of this header + size of fid */ 138 u8 flags; /* OVL_FH_FLAG_* */ 139 u8 type; /* fid_type of fid */ 140 uuid_t uuid; /* uuid of filesystem */ 141 u32 fid[]; /* file identifier should be 32bit aligned in-memory */ 142 } __packed; 143 144 /* In-memory and on-wire format for overlay file handle */ 145 struct ovl_fh { 146 u8 padding[3]; /* make sure fb.fid is 32bit aligned */ 147 union { 148 struct ovl_fb fb; 149 DECLARE_FLEX_ARRAY(u8, buf); 150 }; 151 } __packed; 152 153 #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb) 154 #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len) 155 #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \ 156 offsetof(struct ovl_fb, fid)) 157 158 /* On-disk format for "metacopy" xattr (if non-zero size) */ 159 struct ovl_metacopy { 160 u8 version; /* 0 */ 161 u8 len; /* size of this header + used digest bytes */ 162 u8 flags; 163 u8 digest_algo; /* FS_VERITY_HASH_ALG_* constant, 0 for no digest */ 164 u8 digest[FS_VERITY_MAX_DIGEST_SIZE]; /* Only the used part on disk */ 165 } __packed; 166 167 #define OVL_METACOPY_MAX_SIZE (sizeof(struct ovl_metacopy)) 168 #define OVL_METACOPY_MIN_SIZE (OVL_METACOPY_MAX_SIZE - FS_VERITY_MAX_DIGEST_SIZE) 169 #define OVL_METACOPY_INIT { 0, OVL_METACOPY_MIN_SIZE } 170 171 static inline int ovl_metadata_digest_size(const struct ovl_metacopy *metacopy) 172 { 173 if (metacopy->len < OVL_METACOPY_MIN_SIZE) 174 return 0; 175 return (int)metacopy->len - OVL_METACOPY_MIN_SIZE; 176 } 177 178 /* No atime modification on underlying */ 179 #define OVL_OPEN_FLAGS (O_NOATIME) 180 181 extern const char *const ovl_xattr_table[][2]; 182 static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) 183 { 184 return ovl_xattr_table[ox][ofs->config.userxattr]; 185 } 186 187 /* 188 * When changing ownership of an upper object map the intended ownership 189 * according to the upper layer's idmapping. When an upper mount idmaps files 190 * that are stored on-disk as owned by id 1001 to id 1000 this means stat on 191 * this object will report it as being owned by id 1000 when calling stat via 192 * the upper mount. 193 * In order to change ownership of an object so stat reports id 1000 when 194 * called on an idmapped upper mount the value written to disk - i.e., the 195 * value stored in ia_*id - must 1001. The mount mapping helper will thus take 196 * care to map 1000 to 1001. 197 * The mnt idmapping helpers are nops if the upper layer isn't idmapped. 198 */ 199 static inline int ovl_do_notify_change(struct ovl_fs *ofs, 200 struct dentry *upperdentry, 201 struct iattr *attr) 202 { 203 return notify_change(ovl_upper_mnt_idmap(ofs), upperdentry, attr, NULL); 204 } 205 206 static inline int ovl_do_rmdir(struct ovl_fs *ofs, 207 struct inode *dir, struct dentry *dentry) 208 { 209 int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry); 210 211 pr_debug("rmdir(%pd2) = %i\n", dentry, err); 212 return err; 213 } 214 215 static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir, 216 struct dentry *dentry) 217 { 218 int err = vfs_unlink(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL); 219 220 pr_debug("unlink(%pd2) = %i\n", dentry, err); 221 return err; 222 } 223 224 static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry, 225 struct inode *dir, struct dentry *new_dentry) 226 { 227 int err = vfs_link(old_dentry, ovl_upper_mnt_idmap(ofs), dir, 228 new_dentry, NULL); 229 230 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err); 231 return err; 232 } 233 234 static inline int ovl_do_create(struct ovl_fs *ofs, 235 struct inode *dir, struct dentry *dentry, 236 umode_t mode) 237 { 238 int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true); 239 240 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); 241 return err; 242 } 243 244 static inline struct dentry *ovl_do_mkdir(struct ovl_fs *ofs, 245 struct inode *dir, 246 struct dentry *dentry, 247 umode_t mode) 248 { 249 dentry = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode); 250 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, PTR_ERR_OR_ZERO(dentry)); 251 return dentry; 252 } 253 254 static inline int ovl_do_mknod(struct ovl_fs *ofs, 255 struct inode *dir, struct dentry *dentry, 256 umode_t mode, dev_t dev) 257 { 258 int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev); 259 260 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); 261 return err; 262 } 263 264 static inline int ovl_do_symlink(struct ovl_fs *ofs, 265 struct inode *dir, struct dentry *dentry, 266 const char *oldname) 267 { 268 int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname); 269 270 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); 271 return err; 272 } 273 274 static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, 275 void *value, size_t size) 276 { 277 int err, len; 278 279 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb); 280 281 err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry, 282 name, value, size); 283 len = (value && err > 0) ? err : 0; 284 285 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", 286 path->dentry, name, min(len, 48), value, size, err); 287 return err; 288 } 289 290 static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, 291 struct dentry *upperdentry, 292 enum ovl_xattr ox, void *value, 293 size_t size) 294 { 295 struct path upperpath = { 296 .dentry = upperdentry, 297 .mnt = ovl_upper_mnt(ofs), 298 }; 299 300 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size); 301 } 302 303 static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, 304 const struct path *path, 305 enum ovl_xattr ox, void *value, 306 size_t size) 307 { 308 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size); 309 } 310 311 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 312 const char *name, const void *value, 313 size_t size, int flags) 314 { 315 int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name, 316 value, size, flags); 317 318 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n", 319 dentry, name, min((int)size, 48), value, size, flags, err); 320 return err; 321 } 322 323 static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 324 enum ovl_xattr ox, const void *value, 325 size_t size) 326 { 327 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0); 328 } 329 330 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 331 const char *name) 332 { 333 int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name); 334 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); 335 return err; 336 } 337 338 static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 339 enum ovl_xattr ox) 340 { 341 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox)); 342 } 343 344 static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, 345 const char *acl_name, struct posix_acl *acl) 346 { 347 return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl); 348 } 349 350 static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, 351 const char *acl_name) 352 { 353 return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name); 354 } 355 356 static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir, 357 struct dentry *olddentry, struct inode *newdir, 358 struct dentry *newdentry, unsigned int flags) 359 { 360 int err; 361 struct renamedata rd = { 362 .old_mnt_idmap = ovl_upper_mnt_idmap(ofs), 363 .old_dir = olddir, 364 .old_dentry = olddentry, 365 .new_mnt_idmap = ovl_upper_mnt_idmap(ofs), 366 .new_dir = newdir, 367 .new_dentry = newdentry, 368 .flags = flags, 369 }; 370 371 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags); 372 err = vfs_rename(&rd); 373 if (err) { 374 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 375 olddentry, newdentry, err); 376 } 377 return err; 378 } 379 380 static inline int ovl_do_whiteout(struct ovl_fs *ofs, 381 struct inode *dir, struct dentry *dentry) 382 { 383 int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry); 384 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 385 return err; 386 } 387 388 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, 389 struct dentry *dentry, umode_t mode) 390 { 391 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; 392 struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, 393 mode, O_LARGEFILE | O_WRONLY, 394 current_cred()); 395 int err = PTR_ERR_OR_ZERO(file); 396 397 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 398 return file; 399 } 400 401 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, 402 const char *name, 403 struct dentry *base, int len) 404 { 405 return lookup_one(ovl_upper_mnt_idmap(ofs), &QSTR_LEN(name, len), base); 406 } 407 408 static inline bool ovl_open_flags_need_copy_up(int flags) 409 { 410 if (!flags) 411 return false; 412 413 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 414 } 415 416 /* util.c */ 417 int ovl_get_write_access(struct dentry *dentry); 418 void ovl_put_write_access(struct dentry *dentry); 419 void ovl_start_write(struct dentry *dentry); 420 void ovl_end_write(struct dentry *dentry); 421 int ovl_want_write(struct dentry *dentry); 422 void ovl_drop_write(struct dentry *dentry); 423 struct dentry *ovl_workdir(struct dentry *dentry); 424 const struct cred *ovl_override_creds(struct super_block *sb); 425 void ovl_revert_creds(const struct cred *old_cred); 426 427 static inline const struct cred *ovl_creds(struct super_block *sb) 428 { 429 return OVL_FS(sb)->creator_cred; 430 } 431 432 int ovl_can_decode_fh(struct super_block *sb); 433 struct dentry *ovl_indexdir(struct super_block *sb); 434 bool ovl_index_all(struct super_block *sb); 435 bool ovl_verify_lower(struct super_block *sb); 436 struct ovl_path *ovl_stack_alloc(unsigned int n); 437 void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); 438 void ovl_stack_put(struct ovl_path *stack, unsigned int n); 439 void ovl_stack_free(struct ovl_path *stack, unsigned int n); 440 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 441 void ovl_free_entry(struct ovl_entry *oe); 442 bool ovl_dentry_remote(struct dentry *dentry); 443 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); 444 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, 445 struct ovl_entry *oe); 446 void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, 447 struct ovl_entry *oe, unsigned int mask); 448 bool ovl_dentry_weird(struct dentry *dentry); 449 enum ovl_path_type ovl_path_type(struct dentry *dentry); 450 void ovl_path_upper(struct dentry *dentry, struct path *path); 451 void ovl_path_lower(struct dentry *dentry, struct path *path); 452 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 453 struct inode *ovl_i_path_real(struct inode *inode, struct path *path); 454 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 455 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); 456 struct dentry *ovl_dentry_upper(struct dentry *dentry); 457 struct dentry *ovl_dentry_lower(struct dentry *dentry); 458 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 459 int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); 460 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); 461 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 462 struct dentry *ovl_dentry_real(struct dentry *dentry); 463 struct dentry *ovl_i_dentry_upper(struct inode *inode); 464 struct inode *ovl_inode_upper(struct inode *inode); 465 struct inode *ovl_inode_lower(struct inode *inode); 466 struct inode *ovl_inode_lowerdata(struct inode *inode); 467 struct inode *ovl_inode_real(struct inode *inode); 468 struct inode *ovl_inode_realdata(struct inode *inode); 469 const char *ovl_lowerdata_redirect(struct inode *inode); 470 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 471 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 472 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 473 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 474 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 475 bool ovl_dentry_is_opaque(struct dentry *dentry); 476 bool ovl_dentry_is_whiteout(struct dentry *dentry); 477 void ovl_dentry_set_opaque(struct dentry *dentry); 478 bool ovl_dentry_has_xwhiteouts(struct dentry *dentry); 479 void ovl_dentry_set_xwhiteouts(struct dentry *dentry); 480 void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs, 481 const struct ovl_layer *layer); 482 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 483 void ovl_dentry_set_upper_alias(struct dentry *dentry); 484 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 485 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 486 bool ovl_has_upperdata(struct inode *inode); 487 void ovl_set_upperdata(struct inode *inode); 488 const char *ovl_dentry_get_redirect(struct dentry *dentry); 489 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 490 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 491 void ovl_dir_modified(struct dentry *dentry, bool impurity); 492 u64 ovl_inode_version_get(struct inode *inode); 493 bool ovl_is_whiteout(struct dentry *dentry); 494 bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); 495 struct file *ovl_path_open(const struct path *path, int flags); 496 int ovl_copy_up_start(struct dentry *dentry, int flags); 497 void ovl_copy_up_end(struct dentry *dentry); 498 bool ovl_already_copied_up(struct dentry *dentry, int flags); 499 char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path, 500 enum ovl_xattr ox); 501 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); 502 bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path); 503 bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, 504 const struct path *upperpath); 505 506 static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs, 507 struct dentry *upperdentry) 508 { 509 struct path upperpath = { 510 .dentry = upperdentry, 511 .mnt = ovl_upper_mnt(ofs), 512 }; 513 return ovl_path_is_whiteout(ofs, &upperpath); 514 } 515 516 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, 517 struct dentry *upperdentry) 518 { 519 struct path upperpath = { 520 .dentry = upperdentry, 521 .mnt = ovl_upper_mnt(ofs), 522 }; 523 return ovl_path_check_origin_xattr(ofs, &upperpath); 524 } 525 526 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 527 enum ovl_xattr ox, const void *value, size_t size, 528 int xerr); 529 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 530 bool ovl_inuse_trylock(struct dentry *dentry); 531 void ovl_inuse_unlock(struct dentry *dentry); 532 bool ovl_is_inuse(struct dentry *dentry); 533 bool ovl_need_index(struct dentry *dentry); 534 int ovl_nlink_start(struct dentry *dentry); 535 void ovl_nlink_end(struct dentry *dentry); 536 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); 537 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path, 538 struct ovl_metacopy *data); 539 int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d, 540 struct ovl_metacopy *metacopy); 541 bool ovl_is_metacopy_dentry(struct dentry *dentry); 542 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); 543 int ovl_ensure_verity_loaded(struct path *path); 544 int ovl_validate_verity(struct ovl_fs *ofs, 545 struct path *metapath, 546 struct path *datapath); 547 int ovl_get_verity_digest(struct ovl_fs *ofs, struct path *src, 548 struct ovl_metacopy *metacopy); 549 int ovl_sync_status(struct ovl_fs *ofs); 550 551 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 552 { 553 set_bit(flag, &OVL_I(inode)->flags); 554 } 555 556 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 557 { 558 clear_bit(flag, &OVL_I(inode)->flags); 559 } 560 561 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 562 { 563 return test_bit(flag, &OVL_I(inode)->flags); 564 } 565 566 static inline bool ovl_is_impuredir(struct super_block *sb, 567 struct dentry *upperdentry) 568 { 569 struct ovl_fs *ofs = OVL_FS(sb); 570 struct path upperpath = { 571 .dentry = upperdentry, 572 .mnt = ovl_upper_mnt(ofs), 573 }; 574 575 return ovl_get_dir_xattr_val(ofs, &upperpath, OVL_XATTR_IMPURE) == 'y'; 576 } 577 578 static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs, 579 const struct path *path) 580 { 581 return ovl_get_dir_xattr_val(ofs, path, OVL_XATTR_OPAQUE); 582 } 583 584 static inline bool ovl_redirect_follow(struct ovl_fs *ofs) 585 { 586 return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW; 587 } 588 589 static inline bool ovl_redirect_dir(struct ovl_fs *ofs) 590 { 591 return ofs->config.redirect_mode == OVL_REDIRECT_ON; 592 } 593 594 static inline bool ovl_origin_uuid(struct ovl_fs *ofs) 595 { 596 return ofs->config.uuid != OVL_UUID_OFF; 597 } 598 599 static inline bool ovl_has_fsid(struct ovl_fs *ofs) 600 { 601 return ofs->config.uuid == OVL_UUID_ON || 602 ofs->config.uuid == OVL_UUID_AUTO; 603 } 604 605 /* 606 * With xino=auto, we do best effort to keep all inodes on same st_dev and 607 * d_ino consistent with st_ino. 608 * With xino=on, we do the same effort but we warn if we failed. 609 */ 610 static inline bool ovl_xino_warn(struct ovl_fs *ofs) 611 { 612 return ofs->config.xino == OVL_XINO_ON; 613 } 614 615 /* 616 * To avoid regressions in existing setups with overlay lower offline changes, 617 * we allow lower changes only if none of the new features are used. 618 */ 619 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 620 { 621 return (!ofs->config.index && !ofs->config.metacopy && 622 !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs)); 623 } 624 625 /* All layers on same fs? */ 626 static inline bool ovl_same_fs(struct ovl_fs *ofs) 627 { 628 return ofs->xino_mode == 0; 629 } 630 631 /* All overlay inodes have same st_dev? */ 632 static inline bool ovl_same_dev(struct ovl_fs *ofs) 633 { 634 return ofs->xino_mode >= 0; 635 } 636 637 static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) 638 { 639 return ovl_same_dev(ofs) ? ofs->xino_mode : 0; 640 } 641 642 static inline void ovl_inode_lock(struct inode *inode) 643 { 644 mutex_lock(&OVL_I(inode)->lock); 645 } 646 647 static inline int ovl_inode_lock_interruptible(struct inode *inode) 648 { 649 return mutex_lock_interruptible(&OVL_I(inode)->lock); 650 } 651 652 static inline void ovl_inode_unlock(struct inode *inode) 653 { 654 mutex_unlock(&OVL_I(inode)->lock); 655 } 656 657 658 /* namei.c */ 659 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 660 661 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 662 { 663 if (fh_len < sizeof(struct ovl_fh)) 664 return -EINVAL; 665 666 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 667 } 668 669 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 670 struct vfsmount *mnt, bool connected); 671 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 672 struct dentry *upperdentry, struct ovl_path **stackp); 673 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 674 enum ovl_xattr ox, const struct ovl_fh *fh, 675 bool is_upper, bool set); 676 int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry, 677 enum ovl_xattr ox, struct dentry *real, 678 bool is_upper, bool set); 679 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, 680 bool connected); 681 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 682 int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name); 683 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 684 struct qstr *name); 685 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 686 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 687 struct dentry *origin, bool verify); 688 int ovl_path_next(int idx, struct dentry *dentry, struct path *path, 689 const struct ovl_layer **layer); 690 int ovl_verify_lowerdata(struct dentry *dentry); 691 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 692 unsigned int flags); 693 bool ovl_lower_positive(struct dentry *dentry); 694 695 static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper, 696 const struct ovl_fh *fh, bool set) 697 { 698 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, fh, false, set); 699 } 700 701 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 702 struct dentry *origin, bool set) 703 { 704 return ovl_verify_origin_xattr(ofs, upper, OVL_XATTR_ORIGIN, origin, 705 false, set); 706 } 707 708 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 709 struct dentry *upper, bool set) 710 { 711 return ovl_verify_origin_xattr(ofs, index, OVL_XATTR_UPPER, upper, 712 true, set); 713 } 714 715 /* readdir.c */ 716 extern const struct file_operations ovl_dir_operations; 717 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 718 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 719 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 720 struct list_head *list); 721 void ovl_cache_free(struct list_head *list); 722 void ovl_dir_cache_free(struct inode *inode); 723 int ovl_check_d_type_supported(const struct path *realpath); 724 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir, 725 struct vfsmount *mnt, struct dentry *dentry, int level); 726 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 727 728 /* 729 * Can we iterate real dir directly? 730 * 731 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 732 * lower dir was removed under it and possibly before it was rotated from upper 733 * to lower layer. 734 */ 735 static inline bool ovl_dir_is_real(struct inode *dir) 736 { 737 return !ovl_test_flag(OVL_WHITEOUTS, dir); 738 } 739 740 /* inode.c */ 741 int ovl_set_nlink_upper(struct dentry *dentry); 742 int ovl_set_nlink_lower(struct dentry *dentry); 743 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 744 struct dentry *upperdentry, 745 unsigned int fallback); 746 int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, 747 int mask); 748 749 #ifdef CONFIG_FS_POSIX_ACL 750 struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, 751 struct inode *inode, int type, 752 bool rcu, bool noperm); 753 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, 754 bool rcu) 755 { 756 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true); 757 } 758 static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, 759 struct dentry *dentry, int type) 760 { 761 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false); 762 } 763 int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 764 struct posix_acl *acl, int type); 765 struct posix_acl *ovl_get_acl_path(const struct path *path, 766 const char *acl_name, bool noperm); 767 #else 768 #define ovl_get_inode_acl NULL 769 #define ovl_get_acl NULL 770 #define ovl_set_acl NULL 771 static inline struct posix_acl *ovl_get_acl_path(const struct path *path, 772 const char *acl_name, 773 bool noperm) 774 { 775 return NULL; 776 } 777 #endif 778 779 int ovl_update_time(struct inode *inode, int flags); 780 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 781 782 struct ovl_inode_params { 783 struct inode *newinode; 784 struct dentry *upperdentry; 785 struct ovl_entry *oe; 786 bool index; 787 char *redirect; 788 char *lowerdata_redirect; 789 }; 790 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 791 unsigned long ino, int fsid); 792 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 793 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 794 bool is_upper); 795 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 796 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 797 struct inode *ovl_get_inode(struct super_block *sb, 798 struct ovl_inode_params *oip); 799 void ovl_copyattr(struct inode *to); 800 801 /* vfs inode flags copied from real to ovl inode */ 802 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE) 803 /* vfs inode flags read from overlay.protattr xattr to ovl inode */ 804 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 805 806 /* 807 * fileattr flags copied from lower to upper inode on copy up. 808 * We cannot copy up immutable/append-only flags, because that would prevent 809 * linking temp inode to upper dir, so we store them in xattr instead. 810 */ 811 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 812 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 813 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 814 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 815 816 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 817 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 818 struct fileattr *fa); 819 820 static inline void ovl_copyflags(struct inode *from, struct inode *to) 821 { 822 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 823 824 inode_set_flags(to, from->i_flags & mask, mask); 825 } 826 827 /* dir.c */ 828 extern const struct inode_operations ovl_dir_inode_operations; 829 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, 830 struct dentry *dentry); 831 struct ovl_cattr { 832 dev_t rdev; 833 umode_t mode; 834 const char *link; 835 struct dentry *hardlink; 836 }; 837 838 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 839 840 struct dentry *ovl_create_real(struct ovl_fs *ofs, 841 struct inode *dir, struct dentry *newdentry, 842 struct ovl_cattr *attr); 843 int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); 844 struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); 845 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, 846 struct ovl_cattr *attr); 847 848 /* file.c */ 849 extern const struct file_operations ovl_file_operations; 850 int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa); 851 int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa); 852 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); 853 int ovl_fileattr_set(struct mnt_idmap *idmap, 854 struct dentry *dentry, struct fileattr *fa); 855 struct ovl_file; 856 struct ovl_file *ovl_file_alloc(struct file *realfile); 857 void ovl_file_free(struct ovl_file *of); 858 859 /* copy_up.c */ 860 int ovl_copy_up(struct dentry *dentry); 861 int ovl_copy_up_with_data(struct dentry *dentry); 862 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 863 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); 864 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); 865 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct inode *realinode, 866 bool is_upper); 867 struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin); 868 int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh, 869 struct dentry *upper); 870 871 /* export.c */ 872 extern const struct export_operations ovl_export_operations; 873 extern const struct export_operations ovl_export_fid_operations; 874 875 /* super.c */ 876 int ovl_fill_super(struct super_block *sb, struct fs_context *fc); 877 878 /* Will this overlay be forced to mount/remount ro? */ 879 static inline bool ovl_force_readonly(struct ovl_fs *ofs) 880 { 881 return (!ovl_upper_mnt(ofs) || !ofs->workdir); 882 } 883 884 /* xattr.c */ 885 886 const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs); 887 int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 888 struct iattr *attr); 889 int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, 890 struct kstat *stat, u32 request_mask, unsigned int flags); 891 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 892