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 int ovl_do_mkdir(struct ovl_fs *ofs, 245 struct inode *dir, struct dentry *dentry, 246 umode_t mode) 247 { 248 int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode); 249 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err); 250 return err; 251 } 252 253 static inline int ovl_do_mknod(struct ovl_fs *ofs, 254 struct inode *dir, struct dentry *dentry, 255 umode_t mode, dev_t dev) 256 { 257 int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev); 258 259 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); 260 return err; 261 } 262 263 static inline int ovl_do_symlink(struct ovl_fs *ofs, 264 struct inode *dir, struct dentry *dentry, 265 const char *oldname) 266 { 267 int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname); 268 269 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); 270 return err; 271 } 272 273 static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, 274 void *value, size_t size) 275 { 276 int err, len; 277 278 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb); 279 280 err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry, 281 name, value, size); 282 len = (value && err > 0) ? err : 0; 283 284 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", 285 path->dentry, name, min(len, 48), value, size, err); 286 return err; 287 } 288 289 static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, 290 struct dentry *upperdentry, 291 enum ovl_xattr ox, void *value, 292 size_t size) 293 { 294 struct path upperpath = { 295 .dentry = upperdentry, 296 .mnt = ovl_upper_mnt(ofs), 297 }; 298 299 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size); 300 } 301 302 static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, 303 const struct path *path, 304 enum ovl_xattr ox, void *value, 305 size_t size) 306 { 307 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size); 308 } 309 310 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 311 const char *name, const void *value, 312 size_t size, int flags) 313 { 314 int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name, 315 value, size, flags); 316 317 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n", 318 dentry, name, min((int)size, 48), value, size, flags, err); 319 return err; 320 } 321 322 static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 323 enum ovl_xattr ox, const void *value, 324 size_t size) 325 { 326 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0); 327 } 328 329 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 330 const char *name) 331 { 332 int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name); 333 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); 334 return err; 335 } 336 337 static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 338 enum ovl_xattr ox) 339 { 340 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox)); 341 } 342 343 static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, 344 const char *acl_name, struct posix_acl *acl) 345 { 346 return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl); 347 } 348 349 static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, 350 const char *acl_name) 351 { 352 return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name); 353 } 354 355 static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir, 356 struct dentry *olddentry, struct inode *newdir, 357 struct dentry *newdentry, unsigned int flags) 358 { 359 int err; 360 struct renamedata rd = { 361 .old_mnt_idmap = ovl_upper_mnt_idmap(ofs), 362 .old_dir = olddir, 363 .old_dentry = olddentry, 364 .new_mnt_idmap = ovl_upper_mnt_idmap(ofs), 365 .new_dir = newdir, 366 .new_dentry = newdentry, 367 .flags = flags, 368 }; 369 370 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags); 371 err = vfs_rename(&rd); 372 if (err) { 373 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 374 olddentry, newdentry, err); 375 } 376 return err; 377 } 378 379 static inline int ovl_do_whiteout(struct ovl_fs *ofs, 380 struct inode *dir, struct dentry *dentry) 381 { 382 int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry); 383 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 384 return err; 385 } 386 387 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, 388 struct dentry *dentry, umode_t mode) 389 { 390 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; 391 struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, 392 mode, O_LARGEFILE | O_WRONLY, 393 current_cred()); 394 int err = PTR_ERR_OR_ZERO(file); 395 396 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 397 return file; 398 } 399 400 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, 401 const char *name, 402 struct dentry *base, int len) 403 { 404 return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len); 405 } 406 407 static inline bool ovl_open_flags_need_copy_up(int flags) 408 { 409 if (!flags) 410 return false; 411 412 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 413 } 414 415 static inline int ovl_do_getattr(const struct path *path, struct kstat *stat, 416 u32 request_mask, unsigned int flags) 417 { 418 if (flags & AT_GETATTR_NOSEC) 419 return vfs_getattr_nosec(path, stat, request_mask, flags); 420 return vfs_getattr(path, stat, request_mask, flags); 421 } 422 423 /* util.c */ 424 int ovl_get_write_access(struct dentry *dentry); 425 void ovl_put_write_access(struct dentry *dentry); 426 void ovl_start_write(struct dentry *dentry); 427 void ovl_end_write(struct dentry *dentry); 428 int ovl_want_write(struct dentry *dentry); 429 void ovl_drop_write(struct dentry *dentry); 430 struct dentry *ovl_workdir(struct dentry *dentry); 431 const struct cred *ovl_override_creds(struct super_block *sb); 432 433 static inline const struct cred *ovl_creds(struct super_block *sb) 434 { 435 return OVL_FS(sb)->creator_cred; 436 } 437 438 int ovl_can_decode_fh(struct super_block *sb); 439 struct dentry *ovl_indexdir(struct super_block *sb); 440 bool ovl_index_all(struct super_block *sb); 441 bool ovl_verify_lower(struct super_block *sb); 442 struct ovl_path *ovl_stack_alloc(unsigned int n); 443 void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); 444 void ovl_stack_put(struct ovl_path *stack, unsigned int n); 445 void ovl_stack_free(struct ovl_path *stack, unsigned int n); 446 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 447 void ovl_free_entry(struct ovl_entry *oe); 448 bool ovl_dentry_remote(struct dentry *dentry); 449 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); 450 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, 451 struct ovl_entry *oe); 452 void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, 453 struct ovl_entry *oe, unsigned int mask); 454 bool ovl_dentry_weird(struct dentry *dentry); 455 enum ovl_path_type ovl_path_type(struct dentry *dentry); 456 void ovl_path_upper(struct dentry *dentry, struct path *path); 457 void ovl_path_lower(struct dentry *dentry, struct path *path); 458 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 459 struct inode *ovl_i_path_real(struct inode *inode, struct path *path); 460 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 461 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); 462 struct dentry *ovl_dentry_upper(struct dentry *dentry); 463 struct dentry *ovl_dentry_lower(struct dentry *dentry); 464 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 465 int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); 466 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); 467 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 468 struct dentry *ovl_dentry_real(struct dentry *dentry); 469 struct dentry *ovl_i_dentry_upper(struct inode *inode); 470 struct inode *ovl_inode_upper(struct inode *inode); 471 struct inode *ovl_inode_lower(struct inode *inode); 472 struct inode *ovl_inode_lowerdata(struct inode *inode); 473 struct inode *ovl_inode_real(struct inode *inode); 474 struct inode *ovl_inode_realdata(struct inode *inode); 475 const char *ovl_lowerdata_redirect(struct inode *inode); 476 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 477 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 478 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 479 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 480 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 481 bool ovl_dentry_is_opaque(struct dentry *dentry); 482 bool ovl_dentry_is_whiteout(struct dentry *dentry); 483 void ovl_dentry_set_opaque(struct dentry *dentry); 484 bool ovl_dentry_has_xwhiteouts(struct dentry *dentry); 485 void ovl_dentry_set_xwhiteouts(struct dentry *dentry); 486 void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs, 487 const struct ovl_layer *layer); 488 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 489 void ovl_dentry_set_upper_alias(struct dentry *dentry); 490 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 491 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 492 bool ovl_has_upperdata(struct inode *inode); 493 void ovl_set_upperdata(struct inode *inode); 494 const char *ovl_dentry_get_redirect(struct dentry *dentry); 495 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 496 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 497 void ovl_dir_modified(struct dentry *dentry, bool impurity); 498 u64 ovl_inode_version_get(struct inode *inode); 499 bool ovl_is_whiteout(struct dentry *dentry); 500 bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); 501 struct file *ovl_path_open(const struct path *path, int flags); 502 int ovl_copy_up_start(struct dentry *dentry, int flags); 503 void ovl_copy_up_end(struct dentry *dentry); 504 bool ovl_already_copied_up(struct dentry *dentry, int flags); 505 char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path, 506 enum ovl_xattr ox); 507 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); 508 bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path); 509 bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, 510 const struct path *upperpath); 511 512 static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs, 513 struct dentry *upperdentry) 514 { 515 struct path upperpath = { 516 .dentry = upperdentry, 517 .mnt = ovl_upper_mnt(ofs), 518 }; 519 return ovl_path_is_whiteout(ofs, &upperpath); 520 } 521 522 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, 523 struct dentry *upperdentry) 524 { 525 struct path upperpath = { 526 .dentry = upperdentry, 527 .mnt = ovl_upper_mnt(ofs), 528 }; 529 return ovl_path_check_origin_xattr(ofs, &upperpath); 530 } 531 532 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 533 enum ovl_xattr ox, const void *value, size_t size, 534 int xerr); 535 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 536 bool ovl_inuse_trylock(struct dentry *dentry); 537 void ovl_inuse_unlock(struct dentry *dentry); 538 bool ovl_is_inuse(struct dentry *dentry); 539 bool ovl_need_index(struct dentry *dentry); 540 int ovl_nlink_start(struct dentry *dentry); 541 void ovl_nlink_end(struct dentry *dentry); 542 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); 543 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path, 544 struct ovl_metacopy *data); 545 int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d, 546 struct ovl_metacopy *metacopy); 547 bool ovl_is_metacopy_dentry(struct dentry *dentry); 548 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); 549 int ovl_ensure_verity_loaded(struct path *path); 550 int ovl_get_verity_xattr(struct ovl_fs *ofs, const struct path *path, 551 u8 *digest_buf, int *buf_length); 552 int ovl_validate_verity(struct ovl_fs *ofs, 553 struct path *metapath, 554 struct path *datapath); 555 int ovl_get_verity_digest(struct ovl_fs *ofs, struct path *src, 556 struct ovl_metacopy *metacopy); 557 int ovl_sync_status(struct ovl_fs *ofs); 558 559 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 560 { 561 set_bit(flag, &OVL_I(inode)->flags); 562 } 563 564 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 565 { 566 clear_bit(flag, &OVL_I(inode)->flags); 567 } 568 569 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 570 { 571 return test_bit(flag, &OVL_I(inode)->flags); 572 } 573 574 static inline bool ovl_is_impuredir(struct super_block *sb, 575 struct dentry *upperdentry) 576 { 577 struct ovl_fs *ofs = OVL_FS(sb); 578 struct path upperpath = { 579 .dentry = upperdentry, 580 .mnt = ovl_upper_mnt(ofs), 581 }; 582 583 return ovl_get_dir_xattr_val(ofs, &upperpath, OVL_XATTR_IMPURE) == 'y'; 584 } 585 586 static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs, 587 const struct path *path) 588 { 589 return ovl_get_dir_xattr_val(ofs, path, OVL_XATTR_OPAQUE); 590 } 591 592 static inline bool ovl_redirect_follow(struct ovl_fs *ofs) 593 { 594 return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW; 595 } 596 597 static inline bool ovl_redirect_dir(struct ovl_fs *ofs) 598 { 599 return ofs->config.redirect_mode == OVL_REDIRECT_ON; 600 } 601 602 static inline bool ovl_origin_uuid(struct ovl_fs *ofs) 603 { 604 return ofs->config.uuid != OVL_UUID_OFF; 605 } 606 607 static inline bool ovl_has_fsid(struct ovl_fs *ofs) 608 { 609 return ofs->config.uuid == OVL_UUID_ON || 610 ofs->config.uuid == OVL_UUID_AUTO; 611 } 612 613 /* 614 * With xino=auto, we do best effort to keep all inodes on same st_dev and 615 * d_ino consistent with st_ino. 616 * With xino=on, we do the same effort but we warn if we failed. 617 */ 618 static inline bool ovl_xino_warn(struct ovl_fs *ofs) 619 { 620 return ofs->config.xino == OVL_XINO_ON; 621 } 622 623 /* 624 * To avoid regressions in existing setups with overlay lower offline changes, 625 * we allow lower changes only if none of the new features are used. 626 */ 627 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 628 { 629 return (!ofs->config.index && !ofs->config.metacopy && 630 !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs)); 631 } 632 633 /* All layers on same fs? */ 634 static inline bool ovl_same_fs(struct ovl_fs *ofs) 635 { 636 return ofs->xino_mode == 0; 637 } 638 639 /* All overlay inodes have same st_dev? */ 640 static inline bool ovl_same_dev(struct ovl_fs *ofs) 641 { 642 return ofs->xino_mode >= 0; 643 } 644 645 static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) 646 { 647 return ovl_same_dev(ofs) ? ofs->xino_mode : 0; 648 } 649 650 static inline void ovl_inode_lock(struct inode *inode) 651 { 652 mutex_lock(&OVL_I(inode)->lock); 653 } 654 655 static inline int ovl_inode_lock_interruptible(struct inode *inode) 656 { 657 return mutex_lock_interruptible(&OVL_I(inode)->lock); 658 } 659 660 static inline void ovl_inode_unlock(struct inode *inode) 661 { 662 mutex_unlock(&OVL_I(inode)->lock); 663 } 664 665 666 /* namei.c */ 667 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 668 669 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 670 { 671 if (fh_len < sizeof(struct ovl_fh)) 672 return -EINVAL; 673 674 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 675 } 676 677 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 678 struct vfsmount *mnt, bool connected); 679 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 680 struct dentry *upperdentry, struct ovl_path **stackp); 681 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 682 enum ovl_xattr ox, const struct ovl_fh *fh, 683 bool is_upper, bool set); 684 int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry, 685 enum ovl_xattr ox, struct dentry *real, 686 bool is_upper, bool set); 687 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, 688 bool connected); 689 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 690 int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name); 691 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 692 struct qstr *name); 693 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 694 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 695 struct dentry *origin, bool verify); 696 int ovl_path_next(int idx, struct dentry *dentry, struct path *path, 697 const struct ovl_layer **layer); 698 int ovl_verify_lowerdata(struct dentry *dentry); 699 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 700 unsigned int flags); 701 bool ovl_lower_positive(struct dentry *dentry); 702 703 static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper, 704 const struct ovl_fh *fh, bool set) 705 { 706 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, fh, false, set); 707 } 708 709 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 710 struct dentry *origin, bool set) 711 { 712 return ovl_verify_origin_xattr(ofs, upper, OVL_XATTR_ORIGIN, origin, 713 false, set); 714 } 715 716 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 717 struct dentry *upper, bool set) 718 { 719 return ovl_verify_origin_xattr(ofs, index, OVL_XATTR_UPPER, upper, 720 true, set); 721 } 722 723 /* readdir.c */ 724 extern const struct file_operations ovl_dir_operations; 725 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 726 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 727 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 728 struct list_head *list); 729 void ovl_cache_free(struct list_head *list); 730 void ovl_dir_cache_free(struct inode *inode); 731 int ovl_check_d_type_supported(const struct path *realpath); 732 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir, 733 struct vfsmount *mnt, struct dentry *dentry, int level); 734 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 735 736 /* 737 * Can we iterate real dir directly? 738 * 739 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 740 * lower dir was removed under it and possibly before it was rotated from upper 741 * to lower layer. 742 */ 743 static inline bool ovl_dir_is_real(struct inode *dir) 744 { 745 return !ovl_test_flag(OVL_WHITEOUTS, dir); 746 } 747 748 /* inode.c */ 749 int ovl_set_nlink_upper(struct dentry *dentry); 750 int ovl_set_nlink_lower(struct dentry *dentry); 751 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 752 struct dentry *upperdentry, 753 unsigned int fallback); 754 int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, 755 int mask); 756 757 #ifdef CONFIG_FS_POSIX_ACL 758 struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, 759 struct inode *inode, int type, 760 bool rcu, bool noperm); 761 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, 762 bool rcu) 763 { 764 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true); 765 } 766 static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, 767 struct dentry *dentry, int type) 768 { 769 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false); 770 } 771 int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 772 struct posix_acl *acl, int type); 773 struct posix_acl *ovl_get_acl_path(const struct path *path, 774 const char *acl_name, bool noperm); 775 #else 776 #define ovl_get_inode_acl NULL 777 #define ovl_get_acl NULL 778 #define ovl_set_acl NULL 779 static inline struct posix_acl *ovl_get_acl_path(const struct path *path, 780 const char *acl_name, 781 bool noperm) 782 { 783 return NULL; 784 } 785 #endif 786 787 int ovl_update_time(struct inode *inode, int flags); 788 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 789 790 struct ovl_inode_params { 791 struct inode *newinode; 792 struct dentry *upperdentry; 793 struct ovl_entry *oe; 794 bool index; 795 char *redirect; 796 char *lowerdata_redirect; 797 }; 798 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 799 unsigned long ino, int fsid); 800 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 801 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 802 bool is_upper); 803 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 804 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 805 struct inode *ovl_get_inode(struct super_block *sb, 806 struct ovl_inode_params *oip); 807 void ovl_copyattr(struct inode *to); 808 809 /* vfs inode flags copied from real to ovl inode */ 810 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE) 811 /* vfs inode flags read from overlay.protattr xattr to ovl inode */ 812 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 813 814 /* 815 * fileattr flags copied from lower to upper inode on copy up. 816 * We cannot copy up immutable/append-only flags, because that would prevent 817 * linking temp inode to upper dir, so we store them in xattr instead. 818 */ 819 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 820 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 821 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 822 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 823 824 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 825 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 826 struct fileattr *fa); 827 828 static inline void ovl_copyflags(struct inode *from, struct inode *to) 829 { 830 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 831 832 inode_set_flags(to, from->i_flags & mask, mask); 833 } 834 835 /* dir.c */ 836 extern const struct inode_operations ovl_dir_inode_operations; 837 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, 838 struct dentry *dentry); 839 struct ovl_cattr { 840 dev_t rdev; 841 umode_t mode; 842 const char *link; 843 struct dentry *hardlink; 844 }; 845 846 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 847 848 int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, 849 struct dentry **newdentry, umode_t mode); 850 struct dentry *ovl_create_real(struct ovl_fs *ofs, 851 struct inode *dir, struct dentry *newdentry, 852 struct ovl_cattr *attr); 853 int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); 854 struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); 855 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, 856 struct ovl_cattr *attr); 857 858 /* file.c */ 859 extern const struct file_operations ovl_file_operations; 860 int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa); 861 int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa); 862 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); 863 int ovl_fileattr_set(struct mnt_idmap *idmap, 864 struct dentry *dentry, struct fileattr *fa); 865 866 /* copy_up.c */ 867 int ovl_copy_up(struct dentry *dentry); 868 int ovl_copy_up_with_data(struct dentry *dentry); 869 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 870 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); 871 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); 872 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, 873 bool is_upper); 874 struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin); 875 int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh, 876 struct dentry *upper); 877 878 /* export.c */ 879 extern const struct export_operations ovl_export_operations; 880 extern const struct export_operations ovl_export_fid_operations; 881 882 /* super.c */ 883 int ovl_fill_super(struct super_block *sb, struct fs_context *fc); 884 885 /* Will this overlay be forced to mount/remount ro? */ 886 static inline bool ovl_force_readonly(struct ovl_fs *ofs) 887 { 888 return (!ovl_upper_mnt(ofs) || !ofs->workdir); 889 } 890 891 /* xattr.c */ 892 893 const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs); 894 int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 895 struct iattr *attr); 896 int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, 897 struct kstat *stat, u32 request_mask, unsigned int flags); 898 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 899