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, NULL); 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), dentry, mode, NULL); 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, NULL); 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, NULL); 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, NULL); 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_rd(struct renamedata *rd) 359 { 360 int err; 361 362 pr_debug("rename(%pd2, %pd2, 0x%x)\n", rd->old_dentry, rd->new_dentry, 363 rd->flags); 364 err = vfs_rename(rd); 365 if (err) { 366 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 367 rd->old_dentry, rd->new_dentry, err); 368 } 369 return err; 370 } 371 372 static inline int ovl_do_rename(struct ovl_fs *ofs, struct dentry *olddir, 373 struct dentry *olddentry, struct dentry *newdir, 374 struct dentry *newdentry, unsigned int flags) 375 { 376 struct renamedata rd = { 377 .mnt_idmap = ovl_upper_mnt_idmap(ofs), 378 .old_parent = olddir, 379 .old_dentry = olddentry, 380 .new_parent = newdir, 381 .new_dentry = newdentry, 382 .flags = flags, 383 }; 384 385 return ovl_do_rename_rd(&rd); 386 } 387 388 static inline int ovl_do_whiteout(struct ovl_fs *ofs, 389 struct inode *dir, struct dentry *dentry) 390 { 391 int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry); 392 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 393 return err; 394 } 395 396 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, 397 struct dentry *dentry, umode_t mode) 398 { 399 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; 400 struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, 401 mode, O_LARGEFILE | O_WRONLY, 402 current_cred()); 403 int err = PTR_ERR_OR_ZERO(file); 404 405 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 406 return file; 407 } 408 409 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, 410 const char *name, 411 struct dentry *base, int len) 412 { 413 return lookup_one(ovl_upper_mnt_idmap(ofs), &QSTR_LEN(name, len), base); 414 } 415 416 static inline struct dentry *ovl_lookup_upper_unlocked(struct ovl_fs *ofs, 417 const char *name, 418 struct dentry *base, 419 int len) 420 { 421 return lookup_one_unlocked(ovl_upper_mnt_idmap(ofs), 422 &QSTR_LEN(name, len), base); 423 } 424 425 static inline struct dentry *ovl_start_creating_upper(struct ovl_fs *ofs, 426 struct dentry *parent, 427 struct qstr *name) 428 { 429 return start_creating(ovl_upper_mnt_idmap(ofs), 430 parent, name); 431 } 432 433 static inline struct dentry *ovl_start_removing_upper(struct ovl_fs *ofs, 434 struct dentry *parent, 435 struct qstr *name) 436 { 437 return start_removing(ovl_upper_mnt_idmap(ofs), 438 parent, name); 439 } 440 441 static inline bool ovl_open_flags_need_copy_up(int flags) 442 { 443 if (!flags) 444 return false; 445 446 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 447 } 448 449 /* util.c */ 450 int ovl_get_write_access(struct dentry *dentry); 451 void ovl_put_write_access(struct dentry *dentry); 452 void ovl_start_write(struct dentry *dentry); 453 void ovl_end_write(struct dentry *dentry); 454 int ovl_want_write(struct dentry *dentry); 455 void ovl_drop_write(struct dentry *dentry); 456 struct dentry *ovl_workdir(struct dentry *dentry); 457 const struct cred *ovl_override_creds(struct super_block *sb); 458 459 EXTEND_CLASS(override_creds, _ovl, ovl_override_creds(sb), struct super_block *sb) 460 461 #define with_ovl_creds(sb) \ 462 scoped_class(override_creds_ovl, __UNIQUE_ID(label), sb) 463 464 static inline const struct cred *ovl_creds(struct super_block *sb) 465 { 466 return OVL_FS(sb)->creator_cred; 467 } 468 469 int ovl_can_decode_fh(struct super_block *sb); 470 struct dentry *ovl_indexdir(struct super_block *sb); 471 bool ovl_index_all(struct super_block *sb); 472 bool ovl_verify_lower(struct super_block *sb); 473 struct ovl_path *ovl_stack_alloc(unsigned int n); 474 void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); 475 void ovl_stack_put(struct ovl_path *stack, unsigned int n); 476 void ovl_stack_free(struct ovl_path *stack, unsigned int n); 477 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 478 void ovl_free_entry(struct ovl_entry *oe); 479 bool ovl_dentry_remote(struct dentry *dentry); 480 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); 481 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, 482 struct ovl_entry *oe); 483 void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, 484 struct ovl_entry *oe, unsigned int mask); 485 bool ovl_dentry_weird(struct dentry *dentry); 486 487 static inline bool ovl_dentry_casefolded(struct dentry *dentry) 488 { 489 return sb_has_encoding(dentry->d_sb) && IS_CASEFOLDED(d_inode(dentry)); 490 } 491 492 enum ovl_path_type ovl_path_type(struct dentry *dentry); 493 void ovl_path_upper(struct dentry *dentry, struct path *path); 494 void ovl_path_lower(struct dentry *dentry, struct path *path); 495 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 496 struct inode *ovl_i_path_real(struct inode *inode, struct path *path); 497 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 498 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); 499 struct dentry *ovl_dentry_upper(struct dentry *dentry); 500 struct dentry *ovl_dentry_lower(struct dentry *dentry); 501 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 502 int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); 503 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); 504 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 505 struct dentry *ovl_dentry_real(struct dentry *dentry); 506 struct dentry *ovl_i_dentry_upper(struct inode *inode); 507 struct inode *ovl_inode_upper(struct inode *inode); 508 struct inode *ovl_inode_lower(struct inode *inode); 509 struct inode *ovl_inode_lowerdata(struct inode *inode); 510 struct inode *ovl_inode_real(struct inode *inode); 511 struct inode *ovl_inode_realdata(struct inode *inode); 512 const char *ovl_lowerdata_redirect(struct inode *inode); 513 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 514 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 515 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 516 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 517 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 518 bool ovl_dentry_is_opaque(struct dentry *dentry); 519 bool ovl_dentry_is_whiteout(struct dentry *dentry); 520 void ovl_dentry_set_opaque(struct dentry *dentry); 521 bool ovl_dentry_has_xwhiteouts(struct dentry *dentry); 522 void ovl_dentry_set_xwhiteouts(struct dentry *dentry); 523 void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs, 524 const struct ovl_layer *layer); 525 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 526 void ovl_dentry_set_upper_alias(struct dentry *dentry); 527 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 528 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 529 bool ovl_has_upperdata(struct inode *inode); 530 void ovl_set_upperdata(struct inode *inode); 531 const char *ovl_dentry_get_redirect(struct dentry *dentry); 532 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 533 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 534 void ovl_dir_modified(struct dentry *dentry, bool impurity); 535 u64 ovl_inode_version_get(struct inode *inode); 536 bool ovl_is_whiteout(struct dentry *dentry); 537 bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); 538 struct file *ovl_path_open(const struct path *path, int flags); 539 int ovl_copy_up_start(struct dentry *dentry, int flags); 540 void ovl_copy_up_end(struct dentry *dentry); 541 bool ovl_already_copied_up(struct dentry *dentry, int flags); 542 char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path, 543 enum ovl_xattr ox); 544 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); 545 bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path); 546 bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, 547 const struct path *upperpath); 548 549 static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs, 550 struct dentry *upperdentry) 551 { 552 struct path upperpath = { 553 .dentry = upperdentry, 554 .mnt = ovl_upper_mnt(ofs), 555 }; 556 return ovl_path_is_whiteout(ofs, &upperpath); 557 } 558 559 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, 560 struct dentry *upperdentry) 561 { 562 struct path upperpath = { 563 .dentry = upperdentry, 564 .mnt = ovl_upper_mnt(ofs), 565 }; 566 return ovl_path_check_origin_xattr(ofs, &upperpath); 567 } 568 569 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 570 enum ovl_xattr ox, const void *value, size_t size, 571 int xerr); 572 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 573 bool ovl_inuse_trylock(struct dentry *dentry); 574 void ovl_inuse_unlock(struct dentry *dentry); 575 bool ovl_is_inuse(struct dentry *dentry); 576 bool ovl_need_index(struct dentry *dentry); 577 int ovl_nlink_start(struct dentry *dentry); 578 void ovl_nlink_end(struct dentry *dentry); 579 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *work, 580 struct dentry *upperdir, struct dentry *upper); 581 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path, 582 struct ovl_metacopy *data); 583 int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d, 584 struct ovl_metacopy *metacopy); 585 bool ovl_is_metacopy_dentry(struct dentry *dentry); 586 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); 587 int ovl_ensure_verity_loaded(const struct path *path); 588 int ovl_validate_verity(struct ovl_fs *ofs, 589 const struct path *metapath, 590 const struct path *datapath); 591 int ovl_get_verity_digest(struct ovl_fs *ofs, const struct path *src, 592 struct ovl_metacopy *metacopy); 593 int ovl_sync_status(struct ovl_fs *ofs); 594 595 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 596 { 597 set_bit(flag, &OVL_I(inode)->flags); 598 } 599 600 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 601 { 602 clear_bit(flag, &OVL_I(inode)->flags); 603 } 604 605 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 606 { 607 return test_bit(flag, &OVL_I(inode)->flags); 608 } 609 610 static inline bool ovl_is_impuredir(struct super_block *sb, 611 struct dentry *upperdentry) 612 { 613 struct ovl_fs *ofs = OVL_FS(sb); 614 struct path upperpath = { 615 .dentry = upperdentry, 616 .mnt = ovl_upper_mnt(ofs), 617 }; 618 619 return ovl_get_dir_xattr_val(ofs, &upperpath, OVL_XATTR_IMPURE) == 'y'; 620 } 621 622 static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs, 623 const struct path *path) 624 { 625 return ovl_get_dir_xattr_val(ofs, path, OVL_XATTR_OPAQUE); 626 } 627 628 static inline bool ovl_redirect_follow(struct ovl_fs *ofs) 629 { 630 return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW; 631 } 632 633 static inline bool ovl_redirect_dir(struct ovl_fs *ofs) 634 { 635 return ofs->config.redirect_mode == OVL_REDIRECT_ON; 636 } 637 638 static inline bool ovl_origin_uuid(struct ovl_fs *ofs) 639 { 640 return ofs->config.uuid != OVL_UUID_OFF; 641 } 642 643 static inline bool ovl_has_fsid(struct ovl_fs *ofs) 644 { 645 return ofs->config.uuid == OVL_UUID_ON || 646 ofs->config.uuid == OVL_UUID_AUTO; 647 } 648 649 /* 650 * With xino=auto, we do best effort to keep all inodes on same st_dev and 651 * d_ino consistent with st_ino. 652 * With xino=on, we do the same effort but we warn if we failed. 653 */ 654 static inline bool ovl_xino_warn(struct ovl_fs *ofs) 655 { 656 return ofs->config.xino == OVL_XINO_ON; 657 } 658 659 /* 660 * To avoid regressions in existing setups with overlay lower offline changes, 661 * we allow lower changes only if none of the new features are used. 662 */ 663 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 664 { 665 return (!ofs->config.index && !ofs->config.metacopy && 666 !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs)); 667 } 668 669 /* All layers on same fs? */ 670 static inline bool ovl_same_fs(struct ovl_fs *ofs) 671 { 672 return ofs->xino_mode == 0; 673 } 674 675 /* All overlay inodes have same st_dev? */ 676 static inline bool ovl_same_dev(struct ovl_fs *ofs) 677 { 678 return ofs->xino_mode >= 0; 679 } 680 681 static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) 682 { 683 return ovl_same_dev(ofs) ? ofs->xino_mode : 0; 684 } 685 686 static inline void ovl_inode_lock(struct inode *inode) 687 { 688 mutex_lock(&OVL_I(inode)->lock); 689 } 690 691 static inline int ovl_inode_lock_interruptible(struct inode *inode) 692 { 693 return mutex_lock_interruptible(&OVL_I(inode)->lock); 694 } 695 696 static inline void ovl_inode_unlock(struct inode *inode) 697 { 698 mutex_unlock(&OVL_I(inode)->lock); 699 } 700 701 702 /* namei.c */ 703 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 704 705 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 706 { 707 if (fh_len < sizeof(struct ovl_fh)) 708 return -EINVAL; 709 710 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 711 } 712 713 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 714 struct vfsmount *mnt, bool connected); 715 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 716 struct dentry *upperdentry, struct ovl_path **stackp); 717 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 718 enum ovl_xattr ox, const struct ovl_fh *fh, 719 bool is_upper, bool set); 720 int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry, 721 enum ovl_xattr ox, struct dentry *real, 722 bool is_upper, bool set); 723 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, 724 bool connected); 725 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 726 int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name); 727 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 728 struct qstr *name); 729 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 730 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 731 struct dentry *origin, bool verify); 732 int ovl_path_next(int idx, struct dentry *dentry, struct path *path, 733 const struct ovl_layer **layer); 734 int ovl_verify_lowerdata(struct dentry *dentry); 735 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 736 unsigned int flags); 737 bool ovl_lower_positive(struct dentry *dentry); 738 739 static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper, 740 const struct ovl_fh *fh, bool set) 741 { 742 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, fh, false, set); 743 } 744 745 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 746 struct dentry *origin, bool set) 747 { 748 return ovl_verify_origin_xattr(ofs, upper, OVL_XATTR_ORIGIN, origin, 749 false, set); 750 } 751 752 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 753 struct dentry *upper, bool set) 754 { 755 return ovl_verify_origin_xattr(ofs, index, OVL_XATTR_UPPER, upper, 756 true, set); 757 } 758 759 /* readdir.c */ 760 extern const struct file_operations ovl_dir_operations; 761 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 762 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 763 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 764 struct list_head *list); 765 void ovl_cache_free(struct list_head *list); 766 void ovl_dir_cache_free(struct inode *inode); 767 int ovl_check_d_type_supported(const struct path *realpath); 768 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct dentry *parent, 769 struct vfsmount *mnt, struct dentry *dentry, int level); 770 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 771 772 /* 773 * Can we iterate real dir directly? 774 * 775 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 776 * lower dir was removed under it and possibly before it was rotated from upper 777 * to lower layer. 778 */ 779 static inline bool ovl_dir_is_real(struct inode *dir) 780 { 781 return !ovl_test_flag(OVL_WHITEOUTS, dir); 782 } 783 784 /* inode.c */ 785 int ovl_set_nlink_upper(struct dentry *dentry); 786 int ovl_set_nlink_lower(struct dentry *dentry); 787 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 788 struct dentry *upperdentry, 789 unsigned int fallback); 790 int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, 791 int mask); 792 793 #ifdef CONFIG_FS_POSIX_ACL 794 struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, 795 struct inode *inode, int type, 796 bool rcu, bool noperm); 797 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, 798 bool rcu) 799 { 800 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true); 801 } 802 static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, 803 struct dentry *dentry, int type) 804 { 805 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false); 806 } 807 int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 808 struct posix_acl *acl, int type); 809 struct posix_acl *ovl_get_acl_path(const struct path *path, 810 const char *acl_name, bool noperm); 811 #else 812 #define ovl_get_inode_acl NULL 813 #define ovl_get_acl NULL 814 #define ovl_set_acl NULL 815 static inline struct posix_acl *ovl_get_acl_path(const struct path *path, 816 const char *acl_name, 817 bool noperm) 818 { 819 return NULL; 820 } 821 #endif 822 823 int ovl_update_time(struct inode *inode, int flags); 824 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 825 826 struct ovl_inode_params { 827 struct inode *newinode; 828 struct dentry *upperdentry; 829 struct ovl_entry *oe; 830 bool index; 831 char *redirect; 832 char *lowerdata_redirect; 833 }; 834 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 835 unsigned long ino, int fsid); 836 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 837 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 838 bool is_upper); 839 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 840 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 841 struct inode *ovl_get_inode(struct super_block *sb, 842 struct ovl_inode_params *oip); 843 void ovl_copyattr(struct inode *to); 844 845 /* vfs fileattr flags read from overlay.protattr xattr to ovl inode */ 846 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 847 /* vfs fileattr flags copied from real to ovl inode */ 848 #define OVL_FATTR_I_FLAGS_MASK (OVL_PROT_I_FLAGS_MASK | S_SYNC | S_NOATIME) 849 /* vfs inode flags copied from real to ovl inode */ 850 #define OVL_COPY_I_FLAGS_MASK (OVL_FATTR_I_FLAGS_MASK | S_CASEFOLD) 851 852 /* 853 * fileattr flags copied from lower to upper inode on copy up. 854 * We cannot copy up immutable/append-only flags, because that would prevent 855 * linking temp inode to upper dir, so we store them in xattr instead. 856 */ 857 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 858 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 859 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 860 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 861 862 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 863 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 864 struct file_kattr *fa); 865 866 static inline void ovl_copyflags(struct inode *from, struct inode *to) 867 { 868 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 869 870 inode_set_flags(to, from->i_flags & mask, mask); 871 } 872 873 /* dir.c */ 874 extern const struct inode_operations ovl_dir_inode_operations; 875 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct dentry *dir, 876 struct dentry *dentry); 877 struct ovl_cattr { 878 dev_t rdev; 879 umode_t mode; 880 const char *link; 881 struct dentry *hardlink; 882 }; 883 884 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 885 886 struct dentry *ovl_create_real(struct ovl_fs *ofs, 887 struct dentry *parent, struct dentry *newdentry, 888 struct ovl_cattr *attr); 889 int ovl_cleanup(struct ovl_fs *ofs, struct dentry *workdir, struct dentry *dentry); 890 #define OVL_TEMPNAME_SIZE 20 891 void ovl_tempname(char name[OVL_TEMPNAME_SIZE]); 892 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, 893 struct ovl_cattr *attr); 894 895 /* file.c */ 896 extern const struct file_operations ovl_file_operations; 897 int ovl_real_fileattr_get(const struct path *realpath, struct file_kattr *fa); 898 int ovl_real_fileattr_set(const struct path *realpath, struct file_kattr *fa); 899 int ovl_fileattr_get(struct dentry *dentry, struct file_kattr *fa); 900 int ovl_fileattr_set(struct mnt_idmap *idmap, 901 struct dentry *dentry, struct file_kattr *fa); 902 struct ovl_file; 903 struct ovl_file *ovl_file_alloc(struct file *realfile); 904 void ovl_file_free(struct ovl_file *of); 905 906 /* copy_up.c */ 907 int ovl_copy_up(struct dentry *dentry); 908 int ovl_copy_up_with_data(struct dentry *dentry); 909 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 910 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); 911 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); 912 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct inode *realinode, 913 bool is_upper); 914 struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin); 915 int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh, 916 struct dentry *upper); 917 918 /* export.c */ 919 extern const struct export_operations ovl_export_operations; 920 extern const struct export_operations ovl_export_fid_operations; 921 922 /* super.c */ 923 int ovl_fill_super(struct super_block *sb, struct fs_context *fc); 924 925 /* Will this overlay be forced to mount/remount ro? */ 926 static inline bool ovl_force_readonly(struct ovl_fs *ofs) 927 { 928 return (!ovl_upper_mnt(ofs) || !ofs->workdir); 929 } 930 931 /* xattr.c */ 932 933 const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs); 934 int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 935 struct iattr *attr); 936 int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, 937 struct kstat *stat, u32 request_mask, unsigned int flags); 938 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 939