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 struct dentry *ret; 250 251 ret = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode); 252 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, PTR_ERR_OR_ZERO(ret)); 253 return ret; 254 } 255 256 static inline int ovl_do_mknod(struct ovl_fs *ofs, 257 struct inode *dir, struct dentry *dentry, 258 umode_t mode, dev_t dev) 259 { 260 int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev); 261 262 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); 263 return err; 264 } 265 266 static inline int ovl_do_symlink(struct ovl_fs *ofs, 267 struct inode *dir, struct dentry *dentry, 268 const char *oldname) 269 { 270 int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname); 271 272 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); 273 return err; 274 } 275 276 static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, 277 void *value, size_t size) 278 { 279 int err, len; 280 281 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb); 282 283 err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry, 284 name, value, size); 285 len = (value && err > 0) ? err : 0; 286 287 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", 288 path->dentry, name, min(len, 48), value, size, err); 289 return err; 290 } 291 292 static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, 293 struct dentry *upperdentry, 294 enum ovl_xattr ox, void *value, 295 size_t size) 296 { 297 struct path upperpath = { 298 .dentry = upperdentry, 299 .mnt = ovl_upper_mnt(ofs), 300 }; 301 302 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size); 303 } 304 305 static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, 306 const struct path *path, 307 enum ovl_xattr ox, void *value, 308 size_t size) 309 { 310 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size); 311 } 312 313 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 314 const char *name, const void *value, 315 size_t size, int flags) 316 { 317 int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name, 318 value, size, flags); 319 320 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n", 321 dentry, name, min((int)size, 48), value, size, flags, err); 322 return err; 323 } 324 325 static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 326 enum ovl_xattr ox, const void *value, 327 size_t size) 328 { 329 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0); 330 } 331 332 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 333 const char *name) 334 { 335 int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name); 336 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); 337 return err; 338 } 339 340 static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 341 enum ovl_xattr ox) 342 { 343 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox)); 344 } 345 346 static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, 347 const char *acl_name, struct posix_acl *acl) 348 { 349 return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl); 350 } 351 352 static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, 353 const char *acl_name) 354 { 355 return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name); 356 } 357 358 static inline int ovl_do_rename(struct ovl_fs *ofs, struct dentry *olddir, 359 struct dentry *olddentry, struct dentry *newdir, 360 struct dentry *newdentry, unsigned int flags) 361 { 362 int err; 363 struct renamedata rd = { 364 .mnt_idmap = ovl_upper_mnt_idmap(ofs), 365 .old_parent = olddir, 366 .old_dentry = olddentry, 367 .new_parent = newdir, 368 .new_dentry = newdentry, 369 .flags = flags, 370 }; 371 372 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags); 373 err = vfs_rename(&rd); 374 if (err) { 375 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 376 olddentry, newdentry, err); 377 } 378 return err; 379 } 380 381 static inline int ovl_do_whiteout(struct ovl_fs *ofs, 382 struct inode *dir, struct dentry *dentry) 383 { 384 int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry); 385 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 386 return err; 387 } 388 389 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, 390 struct dentry *dentry, umode_t mode) 391 { 392 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; 393 struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, 394 mode, O_LARGEFILE | O_WRONLY, 395 current_cred()); 396 int err = PTR_ERR_OR_ZERO(file); 397 398 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 399 return file; 400 } 401 402 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, 403 const char *name, 404 struct dentry *base, int len) 405 { 406 return lookup_one(ovl_upper_mnt_idmap(ofs), &QSTR_LEN(name, len), base); 407 } 408 409 static inline struct dentry *ovl_lookup_upper_unlocked(struct ovl_fs *ofs, 410 const char *name, 411 struct dentry *base, 412 int len) 413 { 414 return lookup_one_unlocked(ovl_upper_mnt_idmap(ofs), 415 &QSTR_LEN(name, len), base); 416 } 417 418 static inline bool ovl_open_flags_need_copy_up(int flags) 419 { 420 if (!flags) 421 return false; 422 423 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 424 } 425 426 /* util.c */ 427 int ovl_parent_lock(struct dentry *parent, struct dentry *child); 428 static inline void ovl_parent_unlock(struct dentry *parent) 429 { 430 inode_unlock(parent->d_inode); 431 } 432 int ovl_get_write_access(struct dentry *dentry); 433 void ovl_put_write_access(struct dentry *dentry); 434 void ovl_start_write(struct dentry *dentry); 435 void ovl_end_write(struct dentry *dentry); 436 int ovl_want_write(struct dentry *dentry); 437 void ovl_drop_write(struct dentry *dentry); 438 struct dentry *ovl_workdir(struct dentry *dentry); 439 const struct cred *ovl_override_creds(struct super_block *sb); 440 void ovl_revert_creds(const struct cred *old_cred); 441 442 static inline const struct cred *ovl_creds(struct super_block *sb) 443 { 444 return OVL_FS(sb)->creator_cred; 445 } 446 447 int ovl_can_decode_fh(struct super_block *sb); 448 struct dentry *ovl_indexdir(struct super_block *sb); 449 bool ovl_index_all(struct super_block *sb); 450 bool ovl_verify_lower(struct super_block *sb); 451 struct ovl_path *ovl_stack_alloc(unsigned int n); 452 void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); 453 void ovl_stack_put(struct ovl_path *stack, unsigned int n); 454 void ovl_stack_free(struct ovl_path *stack, unsigned int n); 455 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 456 void ovl_free_entry(struct ovl_entry *oe); 457 bool ovl_dentry_remote(struct dentry *dentry); 458 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); 459 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, 460 struct ovl_entry *oe); 461 void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, 462 struct ovl_entry *oe, unsigned int mask); 463 bool ovl_dentry_weird(struct dentry *dentry); 464 465 static inline bool ovl_dentry_casefolded(struct dentry *dentry) 466 { 467 return sb_has_encoding(dentry->d_sb) && IS_CASEFOLDED(d_inode(dentry)); 468 } 469 470 enum ovl_path_type ovl_path_type(struct dentry *dentry); 471 void ovl_path_upper(struct dentry *dentry, struct path *path); 472 void ovl_path_lower(struct dentry *dentry, struct path *path); 473 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 474 struct inode *ovl_i_path_real(struct inode *inode, struct path *path); 475 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 476 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); 477 struct dentry *ovl_dentry_upper(struct dentry *dentry); 478 struct dentry *ovl_dentry_lower(struct dentry *dentry); 479 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 480 int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); 481 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); 482 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 483 struct dentry *ovl_dentry_real(struct dentry *dentry); 484 struct dentry *ovl_i_dentry_upper(struct inode *inode); 485 struct inode *ovl_inode_upper(struct inode *inode); 486 struct inode *ovl_inode_lower(struct inode *inode); 487 struct inode *ovl_inode_lowerdata(struct inode *inode); 488 struct inode *ovl_inode_real(struct inode *inode); 489 struct inode *ovl_inode_realdata(struct inode *inode); 490 const char *ovl_lowerdata_redirect(struct inode *inode); 491 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 492 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 493 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 494 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 495 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 496 bool ovl_dentry_is_opaque(struct dentry *dentry); 497 bool ovl_dentry_is_whiteout(struct dentry *dentry); 498 void ovl_dentry_set_opaque(struct dentry *dentry); 499 bool ovl_dentry_has_xwhiteouts(struct dentry *dentry); 500 void ovl_dentry_set_xwhiteouts(struct dentry *dentry); 501 void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs, 502 const struct ovl_layer *layer); 503 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 504 void ovl_dentry_set_upper_alias(struct dentry *dentry); 505 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 506 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 507 bool ovl_has_upperdata(struct inode *inode); 508 void ovl_set_upperdata(struct inode *inode); 509 const char *ovl_dentry_get_redirect(struct dentry *dentry); 510 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 511 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 512 void ovl_dir_modified(struct dentry *dentry, bool impurity); 513 u64 ovl_inode_version_get(struct inode *inode); 514 bool ovl_is_whiteout(struct dentry *dentry); 515 bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); 516 struct file *ovl_path_open(const struct path *path, int flags); 517 int ovl_copy_up_start(struct dentry *dentry, int flags); 518 void ovl_copy_up_end(struct dentry *dentry); 519 bool ovl_already_copied_up(struct dentry *dentry, int flags); 520 char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path, 521 enum ovl_xattr ox); 522 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); 523 bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path); 524 bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, 525 const struct path *upperpath); 526 527 static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs, 528 struct dentry *upperdentry) 529 { 530 struct path upperpath = { 531 .dentry = upperdentry, 532 .mnt = ovl_upper_mnt(ofs), 533 }; 534 return ovl_path_is_whiteout(ofs, &upperpath); 535 } 536 537 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, 538 struct dentry *upperdentry) 539 { 540 struct path upperpath = { 541 .dentry = upperdentry, 542 .mnt = ovl_upper_mnt(ofs), 543 }; 544 return ovl_path_check_origin_xattr(ofs, &upperpath); 545 } 546 547 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 548 enum ovl_xattr ox, const void *value, size_t size, 549 int xerr); 550 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 551 bool ovl_inuse_trylock(struct dentry *dentry); 552 void ovl_inuse_unlock(struct dentry *dentry); 553 bool ovl_is_inuse(struct dentry *dentry); 554 bool ovl_need_index(struct dentry *dentry); 555 int ovl_nlink_start(struct dentry *dentry); 556 void ovl_nlink_end(struct dentry *dentry); 557 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *work, 558 struct dentry *upperdir, struct dentry *upper); 559 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path, 560 struct ovl_metacopy *data); 561 int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d, 562 struct ovl_metacopy *metacopy); 563 bool ovl_is_metacopy_dentry(struct dentry *dentry); 564 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); 565 int ovl_ensure_verity_loaded(const struct path *path); 566 int ovl_validate_verity(struct ovl_fs *ofs, 567 const struct path *metapath, 568 const struct path *datapath); 569 int ovl_get_verity_digest(struct ovl_fs *ofs, const struct path *src, 570 struct ovl_metacopy *metacopy); 571 int ovl_sync_status(struct ovl_fs *ofs); 572 573 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 574 { 575 set_bit(flag, &OVL_I(inode)->flags); 576 } 577 578 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 579 { 580 clear_bit(flag, &OVL_I(inode)->flags); 581 } 582 583 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 584 { 585 return test_bit(flag, &OVL_I(inode)->flags); 586 } 587 588 static inline bool ovl_is_impuredir(struct super_block *sb, 589 struct dentry *upperdentry) 590 { 591 struct ovl_fs *ofs = OVL_FS(sb); 592 struct path upperpath = { 593 .dentry = upperdentry, 594 .mnt = ovl_upper_mnt(ofs), 595 }; 596 597 return ovl_get_dir_xattr_val(ofs, &upperpath, OVL_XATTR_IMPURE) == 'y'; 598 } 599 600 static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs, 601 const struct path *path) 602 { 603 return ovl_get_dir_xattr_val(ofs, path, OVL_XATTR_OPAQUE); 604 } 605 606 static inline bool ovl_redirect_follow(struct ovl_fs *ofs) 607 { 608 return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW; 609 } 610 611 static inline bool ovl_redirect_dir(struct ovl_fs *ofs) 612 { 613 return ofs->config.redirect_mode == OVL_REDIRECT_ON; 614 } 615 616 static inline bool ovl_origin_uuid(struct ovl_fs *ofs) 617 { 618 return ofs->config.uuid != OVL_UUID_OFF; 619 } 620 621 static inline bool ovl_has_fsid(struct ovl_fs *ofs) 622 { 623 return ofs->config.uuid == OVL_UUID_ON || 624 ofs->config.uuid == OVL_UUID_AUTO; 625 } 626 627 /* 628 * With xino=auto, we do best effort to keep all inodes on same st_dev and 629 * d_ino consistent with st_ino. 630 * With xino=on, we do the same effort but we warn if we failed. 631 */ 632 static inline bool ovl_xino_warn(struct ovl_fs *ofs) 633 { 634 return ofs->config.xino == OVL_XINO_ON; 635 } 636 637 /* 638 * To avoid regressions in existing setups with overlay lower offline changes, 639 * we allow lower changes only if none of the new features are used. 640 */ 641 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 642 { 643 return (!ofs->config.index && !ofs->config.metacopy && 644 !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs)); 645 } 646 647 /* All layers on same fs? */ 648 static inline bool ovl_same_fs(struct ovl_fs *ofs) 649 { 650 return ofs->xino_mode == 0; 651 } 652 653 /* All overlay inodes have same st_dev? */ 654 static inline bool ovl_same_dev(struct ovl_fs *ofs) 655 { 656 return ofs->xino_mode >= 0; 657 } 658 659 static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) 660 { 661 return ovl_same_dev(ofs) ? ofs->xino_mode : 0; 662 } 663 664 static inline void ovl_inode_lock(struct inode *inode) 665 { 666 mutex_lock(&OVL_I(inode)->lock); 667 } 668 669 static inline int ovl_inode_lock_interruptible(struct inode *inode) 670 { 671 return mutex_lock_interruptible(&OVL_I(inode)->lock); 672 } 673 674 static inline void ovl_inode_unlock(struct inode *inode) 675 { 676 mutex_unlock(&OVL_I(inode)->lock); 677 } 678 679 680 /* namei.c */ 681 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 682 683 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 684 { 685 if (fh_len < sizeof(struct ovl_fh)) 686 return -EINVAL; 687 688 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 689 } 690 691 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 692 struct vfsmount *mnt, bool connected); 693 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 694 struct dentry *upperdentry, struct ovl_path **stackp); 695 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 696 enum ovl_xattr ox, const struct ovl_fh *fh, 697 bool is_upper, bool set); 698 int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry, 699 enum ovl_xattr ox, struct dentry *real, 700 bool is_upper, bool set); 701 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, 702 bool connected); 703 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 704 int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name); 705 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 706 struct qstr *name); 707 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 708 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 709 struct dentry *origin, bool verify); 710 int ovl_path_next(int idx, struct dentry *dentry, struct path *path, 711 const struct ovl_layer **layer); 712 int ovl_verify_lowerdata(struct dentry *dentry); 713 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 714 unsigned int flags); 715 bool ovl_lower_positive(struct dentry *dentry); 716 717 static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper, 718 const struct ovl_fh *fh, bool set) 719 { 720 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, fh, false, set); 721 } 722 723 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 724 struct dentry *origin, bool set) 725 { 726 return ovl_verify_origin_xattr(ofs, upper, OVL_XATTR_ORIGIN, origin, 727 false, set); 728 } 729 730 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 731 struct dentry *upper, bool set) 732 { 733 return ovl_verify_origin_xattr(ofs, index, OVL_XATTR_UPPER, upper, 734 true, set); 735 } 736 737 /* readdir.c */ 738 extern const struct file_operations ovl_dir_operations; 739 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 740 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 741 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 742 struct list_head *list); 743 void ovl_cache_free(struct list_head *list); 744 void ovl_dir_cache_free(struct inode *inode); 745 int ovl_check_d_type_supported(const struct path *realpath); 746 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct dentry *parent, 747 struct vfsmount *mnt, struct dentry *dentry, int level); 748 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 749 750 /* 751 * Can we iterate real dir directly? 752 * 753 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 754 * lower dir was removed under it and possibly before it was rotated from upper 755 * to lower layer. 756 */ 757 static inline bool ovl_dir_is_real(struct inode *dir) 758 { 759 return !ovl_test_flag(OVL_WHITEOUTS, dir); 760 } 761 762 /* inode.c */ 763 int ovl_set_nlink_upper(struct dentry *dentry); 764 int ovl_set_nlink_lower(struct dentry *dentry); 765 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 766 struct dentry *upperdentry, 767 unsigned int fallback); 768 int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, 769 int mask); 770 771 #ifdef CONFIG_FS_POSIX_ACL 772 struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, 773 struct inode *inode, int type, 774 bool rcu, bool noperm); 775 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, 776 bool rcu) 777 { 778 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true); 779 } 780 static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, 781 struct dentry *dentry, int type) 782 { 783 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false); 784 } 785 int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 786 struct posix_acl *acl, int type); 787 struct posix_acl *ovl_get_acl_path(const struct path *path, 788 const char *acl_name, bool noperm); 789 #else 790 #define ovl_get_inode_acl NULL 791 #define ovl_get_acl NULL 792 #define ovl_set_acl NULL 793 static inline struct posix_acl *ovl_get_acl_path(const struct path *path, 794 const char *acl_name, 795 bool noperm) 796 { 797 return NULL; 798 } 799 #endif 800 801 int ovl_update_time(struct inode *inode, int flags); 802 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 803 804 struct ovl_inode_params { 805 struct inode *newinode; 806 struct dentry *upperdentry; 807 struct ovl_entry *oe; 808 bool index; 809 char *redirect; 810 char *lowerdata_redirect; 811 }; 812 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 813 unsigned long ino, int fsid); 814 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 815 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 816 bool is_upper); 817 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 818 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 819 struct inode *ovl_get_inode(struct super_block *sb, 820 struct ovl_inode_params *oip); 821 void ovl_copyattr(struct inode *to); 822 823 /* vfs fileattr flags read from overlay.protattr xattr to ovl inode */ 824 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 825 /* vfs fileattr flags copied from real to ovl inode */ 826 #define OVL_FATTR_I_FLAGS_MASK (OVL_PROT_I_FLAGS_MASK | S_SYNC | S_NOATIME) 827 /* vfs inode flags copied from real to ovl inode */ 828 #define OVL_COPY_I_FLAGS_MASK (OVL_FATTR_I_FLAGS_MASK | S_CASEFOLD) 829 830 /* 831 * fileattr flags copied from lower to upper inode on copy up. 832 * We cannot copy up immutable/append-only flags, because that would prevent 833 * linking temp inode to upper dir, so we store them in xattr instead. 834 */ 835 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 836 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 837 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 838 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 839 840 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 841 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 842 struct file_kattr *fa); 843 844 static inline void ovl_copyflags(struct inode *from, struct inode *to) 845 { 846 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 847 848 inode_set_flags(to, from->i_flags & mask, mask); 849 } 850 851 /* dir.c */ 852 extern const struct inode_operations ovl_dir_inode_operations; 853 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct dentry *dir, 854 struct dentry *dentry); 855 struct ovl_cattr { 856 dev_t rdev; 857 umode_t mode; 858 const char *link; 859 struct dentry *hardlink; 860 }; 861 862 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 863 864 struct dentry *ovl_create_real(struct ovl_fs *ofs, 865 struct dentry *parent, struct dentry *newdentry, 866 struct ovl_cattr *attr); 867 int ovl_cleanup(struct ovl_fs *ofs, struct dentry *workdir, struct dentry *dentry); 868 struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); 869 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, 870 struct ovl_cattr *attr); 871 872 /* file.c */ 873 extern const struct file_operations ovl_file_operations; 874 int ovl_real_fileattr_get(const struct path *realpath, struct file_kattr *fa); 875 int ovl_real_fileattr_set(const struct path *realpath, struct file_kattr *fa); 876 int ovl_fileattr_get(struct dentry *dentry, struct file_kattr *fa); 877 int ovl_fileattr_set(struct mnt_idmap *idmap, 878 struct dentry *dentry, struct file_kattr *fa); 879 struct ovl_file; 880 struct ovl_file *ovl_file_alloc(struct file *realfile); 881 void ovl_file_free(struct ovl_file *of); 882 883 /* copy_up.c */ 884 int ovl_copy_up(struct dentry *dentry); 885 int ovl_copy_up_with_data(struct dentry *dentry); 886 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 887 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); 888 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); 889 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct inode *realinode, 890 bool is_upper); 891 struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin); 892 int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh, 893 struct dentry *upper); 894 895 /* export.c */ 896 extern const struct export_operations ovl_export_operations; 897 extern const struct export_operations ovl_export_fid_operations; 898 899 /* super.c */ 900 int ovl_fill_super(struct super_block *sb, struct fs_context *fc); 901 902 /* Will this overlay be forced to mount/remount ro? */ 903 static inline bool ovl_force_readonly(struct ovl_fs *ofs) 904 { 905 return (!ovl_upper_mnt(ofs) || !ofs->workdir); 906 } 907 908 /* xattr.c */ 909 910 const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs); 911 int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 912 struct iattr *attr); 913 int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, 914 struct kstat *stat, u32 request_mask, unsigned int flags); 915 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 916