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 extern const char *const ovl_xattr_table[][2]; 179 static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) 180 { 181 return ovl_xattr_table[ox][ofs->config.userxattr]; 182 } 183 184 /* 185 * When changing ownership of an upper object map the intended ownership 186 * according to the upper layer's idmapping. When an upper mount idmaps files 187 * that are stored on-disk as owned by id 1001 to id 1000 this means stat on 188 * this object will report it as being owned by id 1000 when calling stat via 189 * the upper mount. 190 * In order to change ownership of an object so stat reports id 1000 when 191 * called on an idmapped upper mount the value written to disk - i.e., the 192 * value stored in ia_*id - must 1001. The mount mapping helper will thus take 193 * care to map 1000 to 1001. 194 * The mnt idmapping helpers are nops if the upper layer isn't idmapped. 195 */ 196 static inline int ovl_do_notify_change(struct ovl_fs *ofs, 197 struct dentry *upperdentry, 198 struct iattr *attr) 199 { 200 return notify_change(ovl_upper_mnt_idmap(ofs), upperdentry, attr, NULL); 201 } 202 203 static inline int ovl_do_rmdir(struct ovl_fs *ofs, 204 struct inode *dir, struct dentry *dentry) 205 { 206 int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry); 207 208 pr_debug("rmdir(%pd2) = %i\n", dentry, err); 209 return err; 210 } 211 212 static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir, 213 struct dentry *dentry) 214 { 215 int err = vfs_unlink(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL); 216 217 pr_debug("unlink(%pd2) = %i\n", dentry, err); 218 return err; 219 } 220 221 static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry, 222 struct inode *dir, struct dentry *new_dentry) 223 { 224 int err = vfs_link(old_dentry, ovl_upper_mnt_idmap(ofs), dir, 225 new_dentry, NULL); 226 227 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err); 228 return err; 229 } 230 231 static inline int ovl_do_create(struct ovl_fs *ofs, 232 struct inode *dir, struct dentry *dentry, 233 umode_t mode) 234 { 235 int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true); 236 237 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); 238 return err; 239 } 240 241 static inline int ovl_do_mkdir(struct ovl_fs *ofs, 242 struct inode *dir, struct dentry *dentry, 243 umode_t mode) 244 { 245 int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode); 246 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err); 247 return err; 248 } 249 250 static inline int ovl_do_mknod(struct ovl_fs *ofs, 251 struct inode *dir, struct dentry *dentry, 252 umode_t mode, dev_t dev) 253 { 254 int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev); 255 256 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); 257 return err; 258 } 259 260 static inline int ovl_do_symlink(struct ovl_fs *ofs, 261 struct inode *dir, struct dentry *dentry, 262 const char *oldname) 263 { 264 int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname); 265 266 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); 267 return err; 268 } 269 270 static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, 271 void *value, size_t size) 272 { 273 int err, len; 274 275 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb); 276 277 err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry, 278 name, value, size); 279 len = (value && err > 0) ? err : 0; 280 281 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", 282 path->dentry, name, min(len, 48), value, size, err); 283 return err; 284 } 285 286 static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, 287 struct dentry *upperdentry, 288 enum ovl_xattr ox, void *value, 289 size_t size) 290 { 291 struct path upperpath = { 292 .dentry = upperdentry, 293 .mnt = ovl_upper_mnt(ofs), 294 }; 295 296 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size); 297 } 298 299 static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, 300 const struct path *path, 301 enum ovl_xattr ox, void *value, 302 size_t size) 303 { 304 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size); 305 } 306 307 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 308 const char *name, const void *value, 309 size_t size, int flags) 310 { 311 int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name, 312 value, size, flags); 313 314 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n", 315 dentry, name, min((int)size, 48), value, size, flags, err); 316 return err; 317 } 318 319 static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 320 enum ovl_xattr ox, const void *value, 321 size_t size) 322 { 323 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0); 324 } 325 326 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 327 const char *name) 328 { 329 int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name); 330 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); 331 return err; 332 } 333 334 static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 335 enum ovl_xattr ox) 336 { 337 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox)); 338 } 339 340 static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, 341 const char *acl_name, struct posix_acl *acl) 342 { 343 return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl); 344 } 345 346 static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, 347 const char *acl_name) 348 { 349 return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name); 350 } 351 352 static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir, 353 struct dentry *olddentry, struct inode *newdir, 354 struct dentry *newdentry, unsigned int flags) 355 { 356 int err; 357 struct renamedata rd = { 358 .old_mnt_idmap = ovl_upper_mnt_idmap(ofs), 359 .old_dir = olddir, 360 .old_dentry = olddentry, 361 .new_mnt_idmap = ovl_upper_mnt_idmap(ofs), 362 .new_dir = newdir, 363 .new_dentry = newdentry, 364 .flags = flags, 365 }; 366 367 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags); 368 err = vfs_rename(&rd); 369 if (err) { 370 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 371 olddentry, newdentry, err); 372 } 373 return err; 374 } 375 376 static inline int ovl_do_whiteout(struct ovl_fs *ofs, 377 struct inode *dir, struct dentry *dentry) 378 { 379 int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry); 380 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 381 return err; 382 } 383 384 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, 385 struct dentry *dentry, umode_t mode) 386 { 387 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; 388 struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, 389 mode, O_LARGEFILE | O_WRONLY, 390 current_cred()); 391 int err = PTR_ERR_OR_ZERO(file); 392 393 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 394 return file; 395 } 396 397 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, 398 const char *name, 399 struct dentry *base, int len) 400 { 401 return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len); 402 } 403 404 static inline bool ovl_open_flags_need_copy_up(int flags) 405 { 406 if (!flags) 407 return false; 408 409 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 410 } 411 412 static inline int ovl_do_getattr(const struct path *path, struct kstat *stat, 413 u32 request_mask, unsigned int flags) 414 { 415 if (flags & AT_GETATTR_NOSEC) 416 return vfs_getattr_nosec(path, stat, request_mask, flags); 417 return vfs_getattr(path, stat, request_mask, flags); 418 } 419 420 /* util.c */ 421 int ovl_get_write_access(struct dentry *dentry); 422 void ovl_put_write_access(struct dentry *dentry); 423 void ovl_start_write(struct dentry *dentry); 424 void ovl_end_write(struct dentry *dentry); 425 int ovl_want_write(struct dentry *dentry); 426 void ovl_drop_write(struct dentry *dentry); 427 struct dentry *ovl_workdir(struct dentry *dentry); 428 const struct cred *ovl_override_creds(struct super_block *sb); 429 430 static inline const struct cred *ovl_creds(struct super_block *sb) 431 { 432 return OVL_FS(sb)->creator_cred; 433 } 434 435 int ovl_can_decode_fh(struct super_block *sb); 436 struct dentry *ovl_indexdir(struct super_block *sb); 437 bool ovl_index_all(struct super_block *sb); 438 bool ovl_verify_lower(struct super_block *sb); 439 struct ovl_path *ovl_stack_alloc(unsigned int n); 440 void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); 441 void ovl_stack_put(struct ovl_path *stack, unsigned int n); 442 void ovl_stack_free(struct ovl_path *stack, unsigned int n); 443 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 444 void ovl_free_entry(struct ovl_entry *oe); 445 bool ovl_dentry_remote(struct dentry *dentry); 446 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); 447 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, 448 struct ovl_entry *oe); 449 void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, 450 struct ovl_entry *oe, unsigned int mask); 451 bool ovl_dentry_weird(struct dentry *dentry); 452 enum ovl_path_type ovl_path_type(struct dentry *dentry); 453 void ovl_path_upper(struct dentry *dentry, struct path *path); 454 void ovl_path_lower(struct dentry *dentry, struct path *path); 455 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 456 struct inode *ovl_i_path_real(struct inode *inode, struct path *path); 457 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 458 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); 459 struct dentry *ovl_dentry_upper(struct dentry *dentry); 460 struct dentry *ovl_dentry_lower(struct dentry *dentry); 461 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 462 int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); 463 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); 464 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 465 struct dentry *ovl_dentry_real(struct dentry *dentry); 466 struct dentry *ovl_i_dentry_upper(struct inode *inode); 467 struct inode *ovl_inode_upper(struct inode *inode); 468 struct inode *ovl_inode_lower(struct inode *inode); 469 struct inode *ovl_inode_lowerdata(struct inode *inode); 470 struct inode *ovl_inode_real(struct inode *inode); 471 struct inode *ovl_inode_realdata(struct inode *inode); 472 const char *ovl_lowerdata_redirect(struct inode *inode); 473 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 474 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 475 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 476 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 477 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 478 bool ovl_dentry_is_opaque(struct dentry *dentry); 479 bool ovl_dentry_is_whiteout(struct dentry *dentry); 480 void ovl_dentry_set_opaque(struct dentry *dentry); 481 bool ovl_dentry_has_xwhiteouts(struct dentry *dentry); 482 void ovl_dentry_set_xwhiteouts(struct dentry *dentry); 483 void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs, 484 const struct ovl_layer *layer); 485 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 486 void ovl_dentry_set_upper_alias(struct dentry *dentry); 487 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 488 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 489 bool ovl_has_upperdata(struct inode *inode); 490 void ovl_set_upperdata(struct inode *inode); 491 const char *ovl_dentry_get_redirect(struct dentry *dentry); 492 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 493 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 494 void ovl_dir_modified(struct dentry *dentry, bool impurity); 495 u64 ovl_inode_version_get(struct inode *inode); 496 bool ovl_is_whiteout(struct dentry *dentry); 497 bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); 498 struct file *ovl_path_open(const struct path *path, int flags); 499 int ovl_copy_up_start(struct dentry *dentry, int flags); 500 void ovl_copy_up_end(struct dentry *dentry); 501 bool ovl_already_copied_up(struct dentry *dentry, int flags); 502 char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path, 503 enum ovl_xattr ox); 504 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); 505 bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path); 506 bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, 507 const struct path *upperpath); 508 509 static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs, 510 struct dentry *upperdentry) 511 { 512 struct path upperpath = { 513 .dentry = upperdentry, 514 .mnt = ovl_upper_mnt(ofs), 515 }; 516 return ovl_path_is_whiteout(ofs, &upperpath); 517 } 518 519 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, 520 struct dentry *upperdentry) 521 { 522 struct path upperpath = { 523 .dentry = upperdentry, 524 .mnt = ovl_upper_mnt(ofs), 525 }; 526 return ovl_path_check_origin_xattr(ofs, &upperpath); 527 } 528 529 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 530 enum ovl_xattr ox, const void *value, size_t size, 531 int xerr); 532 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 533 bool ovl_inuse_trylock(struct dentry *dentry); 534 void ovl_inuse_unlock(struct dentry *dentry); 535 bool ovl_is_inuse(struct dentry *dentry); 536 bool ovl_need_index(struct dentry *dentry); 537 int ovl_nlink_start(struct dentry *dentry); 538 void ovl_nlink_end(struct dentry *dentry); 539 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); 540 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path, 541 struct ovl_metacopy *data); 542 int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d, 543 struct ovl_metacopy *metacopy); 544 bool ovl_is_metacopy_dentry(struct dentry *dentry); 545 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); 546 int ovl_ensure_verity_loaded(struct path *path); 547 int ovl_get_verity_xattr(struct ovl_fs *ofs, const struct path *path, 548 u8 *digest_buf, int *buf_length); 549 int ovl_validate_verity(struct ovl_fs *ofs, 550 struct path *metapath, 551 struct path *datapath); 552 int ovl_get_verity_digest(struct ovl_fs *ofs, struct path *src, 553 struct ovl_metacopy *metacopy); 554 int ovl_sync_status(struct ovl_fs *ofs); 555 556 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 557 { 558 set_bit(flag, &OVL_I(inode)->flags); 559 } 560 561 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 562 { 563 clear_bit(flag, &OVL_I(inode)->flags); 564 } 565 566 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 567 { 568 return test_bit(flag, &OVL_I(inode)->flags); 569 } 570 571 static inline bool ovl_is_impuredir(struct super_block *sb, 572 struct dentry *upperdentry) 573 { 574 struct ovl_fs *ofs = OVL_FS(sb); 575 struct path upperpath = { 576 .dentry = upperdentry, 577 .mnt = ovl_upper_mnt(ofs), 578 }; 579 580 return ovl_get_dir_xattr_val(ofs, &upperpath, OVL_XATTR_IMPURE) == 'y'; 581 } 582 583 static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs, 584 const struct path *path) 585 { 586 return ovl_get_dir_xattr_val(ofs, path, OVL_XATTR_OPAQUE); 587 } 588 589 static inline bool ovl_redirect_follow(struct ovl_fs *ofs) 590 { 591 return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW; 592 } 593 594 static inline bool ovl_redirect_dir(struct ovl_fs *ofs) 595 { 596 return ofs->config.redirect_mode == OVL_REDIRECT_ON; 597 } 598 599 static inline bool ovl_origin_uuid(struct ovl_fs *ofs) 600 { 601 return ofs->config.uuid != OVL_UUID_OFF; 602 } 603 604 static inline bool ovl_has_fsid(struct ovl_fs *ofs) 605 { 606 return ofs->config.uuid == OVL_UUID_ON || 607 ofs->config.uuid == OVL_UUID_AUTO; 608 } 609 610 /* 611 * With xino=auto, we do best effort to keep all inodes on same st_dev and 612 * d_ino consistent with st_ino. 613 * With xino=on, we do the same effort but we warn if we failed. 614 */ 615 static inline bool ovl_xino_warn(struct ovl_fs *ofs) 616 { 617 return ofs->config.xino == OVL_XINO_ON; 618 } 619 620 /* 621 * To avoid regressions in existing setups with overlay lower offline changes, 622 * we allow lower changes only if none of the new features are used. 623 */ 624 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 625 { 626 return (!ofs->config.index && !ofs->config.metacopy && 627 !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs)); 628 } 629 630 /* All layers on same fs? */ 631 static inline bool ovl_same_fs(struct ovl_fs *ofs) 632 { 633 return ofs->xino_mode == 0; 634 } 635 636 /* All overlay inodes have same st_dev? */ 637 static inline bool ovl_same_dev(struct ovl_fs *ofs) 638 { 639 return ofs->xino_mode >= 0; 640 } 641 642 static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) 643 { 644 return ovl_same_dev(ofs) ? ofs->xino_mode : 0; 645 } 646 647 static inline void ovl_inode_lock(struct inode *inode) 648 { 649 mutex_lock(&OVL_I(inode)->lock); 650 } 651 652 static inline int ovl_inode_lock_interruptible(struct inode *inode) 653 { 654 return mutex_lock_interruptible(&OVL_I(inode)->lock); 655 } 656 657 static inline void ovl_inode_unlock(struct inode *inode) 658 { 659 mutex_unlock(&OVL_I(inode)->lock); 660 } 661 662 663 /* namei.c */ 664 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 665 666 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 667 { 668 if (fh_len < sizeof(struct ovl_fh)) 669 return -EINVAL; 670 671 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 672 } 673 674 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 675 struct vfsmount *mnt, bool connected); 676 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 677 struct dentry *upperdentry, struct ovl_path **stackp); 678 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 679 enum ovl_xattr ox, const struct ovl_fh *fh, 680 bool is_upper, bool set); 681 int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry, 682 enum ovl_xattr ox, struct dentry *real, 683 bool is_upper, bool set); 684 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, 685 bool connected); 686 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 687 int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name); 688 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 689 struct qstr *name); 690 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 691 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 692 struct dentry *origin, bool verify); 693 int ovl_path_next(int idx, struct dentry *dentry, struct path *path, 694 const struct ovl_layer **layer); 695 int ovl_verify_lowerdata(struct dentry *dentry); 696 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 697 unsigned int flags); 698 bool ovl_lower_positive(struct dentry *dentry); 699 700 static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper, 701 const struct ovl_fh *fh, bool set) 702 { 703 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, fh, false, set); 704 } 705 706 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 707 struct dentry *origin, bool set) 708 { 709 return ovl_verify_origin_xattr(ofs, upper, OVL_XATTR_ORIGIN, origin, 710 false, set); 711 } 712 713 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 714 struct dentry *upper, bool set) 715 { 716 return ovl_verify_origin_xattr(ofs, index, OVL_XATTR_UPPER, upper, 717 true, set); 718 } 719 720 /* readdir.c */ 721 extern const struct file_operations ovl_dir_operations; 722 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 723 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 724 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 725 struct list_head *list); 726 void ovl_cache_free(struct list_head *list); 727 void ovl_dir_cache_free(struct inode *inode); 728 int ovl_check_d_type_supported(const struct path *realpath); 729 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir, 730 struct vfsmount *mnt, struct dentry *dentry, int level); 731 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 732 733 /* 734 * Can we iterate real dir directly? 735 * 736 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 737 * lower dir was removed under it and possibly before it was rotated from upper 738 * to lower layer. 739 */ 740 static inline bool ovl_dir_is_real(struct inode *dir) 741 { 742 return !ovl_test_flag(OVL_WHITEOUTS, dir); 743 } 744 745 /* inode.c */ 746 int ovl_set_nlink_upper(struct dentry *dentry); 747 int ovl_set_nlink_lower(struct dentry *dentry); 748 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 749 struct dentry *upperdentry, 750 unsigned int fallback); 751 int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, 752 int mask); 753 754 #ifdef CONFIG_FS_POSIX_ACL 755 struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, 756 struct inode *inode, int type, 757 bool rcu, bool noperm); 758 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, 759 bool rcu) 760 { 761 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true); 762 } 763 static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, 764 struct dentry *dentry, int type) 765 { 766 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false); 767 } 768 int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 769 struct posix_acl *acl, int type); 770 struct posix_acl *ovl_get_acl_path(const struct path *path, 771 const char *acl_name, bool noperm); 772 #else 773 #define ovl_get_inode_acl NULL 774 #define ovl_get_acl NULL 775 #define ovl_set_acl NULL 776 static inline struct posix_acl *ovl_get_acl_path(const struct path *path, 777 const char *acl_name, 778 bool noperm) 779 { 780 return NULL; 781 } 782 #endif 783 784 int ovl_update_time(struct inode *inode, int flags); 785 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 786 787 struct ovl_inode_params { 788 struct inode *newinode; 789 struct dentry *upperdentry; 790 struct ovl_entry *oe; 791 bool index; 792 char *redirect; 793 char *lowerdata_redirect; 794 }; 795 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 796 unsigned long ino, int fsid); 797 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 798 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 799 bool is_upper); 800 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 801 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 802 struct inode *ovl_get_inode(struct super_block *sb, 803 struct ovl_inode_params *oip); 804 void ovl_copyattr(struct inode *to); 805 806 /* vfs inode flags copied from real to ovl inode */ 807 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE) 808 /* vfs inode flags read from overlay.protattr xattr to ovl inode */ 809 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 810 811 /* 812 * fileattr flags copied from lower to upper inode on copy up. 813 * We cannot copy up immutable/append-only flags, because that would prevent 814 * linking temp inode to upper dir, so we store them in xattr instead. 815 */ 816 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 817 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 818 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 819 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 820 821 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 822 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 823 struct fileattr *fa); 824 825 static inline void ovl_copyflags(struct inode *from, struct inode *to) 826 { 827 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 828 829 inode_set_flags(to, from->i_flags & mask, mask); 830 } 831 832 /* dir.c */ 833 extern const struct inode_operations ovl_dir_inode_operations; 834 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, 835 struct dentry *dentry); 836 struct ovl_cattr { 837 dev_t rdev; 838 umode_t mode; 839 const char *link; 840 struct dentry *hardlink; 841 }; 842 843 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 844 845 int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, 846 struct dentry **newdentry, umode_t mode); 847 struct dentry *ovl_create_real(struct ovl_fs *ofs, 848 struct inode *dir, struct dentry *newdentry, 849 struct ovl_cattr *attr); 850 int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); 851 struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); 852 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, 853 struct ovl_cattr *attr); 854 855 /* file.c */ 856 extern const struct file_operations ovl_file_operations; 857 int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa); 858 int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa); 859 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); 860 int ovl_fileattr_set(struct mnt_idmap *idmap, 861 struct dentry *dentry, struct fileattr *fa); 862 863 /* copy_up.c */ 864 int ovl_copy_up(struct dentry *dentry); 865 int ovl_copy_up_with_data(struct dentry *dentry); 866 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 867 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); 868 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); 869 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, 870 bool is_upper); 871 struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin); 872 int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh, 873 struct dentry *upper); 874 875 /* export.c */ 876 extern const struct export_operations ovl_export_operations; 877 extern const struct export_operations ovl_export_fid_operations; 878 879 /* super.c */ 880 int ovl_fill_super(struct super_block *sb, struct fs_context *fc); 881 882 /* Will this overlay be forced to mount/remount ro? */ 883 static inline bool ovl_force_readonly(struct ovl_fs *ofs) 884 { 885 return (!ovl_upper_mnt(ofs) || !ofs->workdir); 886 } 887 888 /* xattr.c */ 889 890 const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs); 891 int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 892 struct iattr *attr); 893 int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, 894 struct kstat *stat, u32 request_mask, unsigned int flags); 895 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 896