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 enum { 103 OVL_FSYNC_VOLATILE, 104 OVL_FSYNC_AUTO, 105 OVL_FSYNC_STRICT, 106 }; 107 108 /* 109 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin, 110 * where: 111 * origin.fh - exported file handle of the lower file 112 * origin.uuid - uuid of the lower filesystem 113 */ 114 #define OVL_FH_VERSION 0 115 #define OVL_FH_MAGIC 0xfb 116 117 /* CPU byte order required for fid decoding: */ 118 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0) 119 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1) 120 /* Is the real inode encoded in fid an upper inode? */ 121 #define OVL_FH_FLAG_PATH_UPPER (1 << 2) 122 123 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \ 124 OVL_FH_FLAG_PATH_UPPER) 125 126 #if defined(__LITTLE_ENDIAN) 127 #define OVL_FH_FLAG_CPU_ENDIAN 0 128 #elif defined(__BIG_ENDIAN) 129 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN 130 #else 131 #error Endianness not defined 132 #endif 133 134 /* The type used to be returned by overlay exportfs for misaligned fid */ 135 #define OVL_FILEID_V0 0xfb 136 /* The type returned by overlay exportfs for 32bit aligned fid */ 137 #define OVL_FILEID_V1 0xf8 138 139 /* On-disk format for "origin" file handle */ 140 struct ovl_fb { 141 u8 version; /* 0 */ 142 u8 magic; /* 0xfb */ 143 u8 len; /* size of this header + size of fid */ 144 u8 flags; /* OVL_FH_FLAG_* */ 145 u8 type; /* fid_type of fid */ 146 uuid_t uuid; /* uuid of filesystem */ 147 u32 fid[]; /* file identifier should be 32bit aligned in-memory */ 148 } __packed; 149 150 /* In-memory and on-wire format for overlay file handle */ 151 struct ovl_fh { 152 u8 padding[3]; /* make sure fb.fid is 32bit aligned */ 153 union { 154 struct ovl_fb fb; 155 DECLARE_FLEX_ARRAY(u8, buf); 156 }; 157 } __packed; 158 159 #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb) 160 #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len) 161 #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \ 162 offsetof(struct ovl_fb, fid)) 163 164 /* On-disk format for "metacopy" xattr (if non-zero size) */ 165 struct ovl_metacopy { 166 u8 version; /* 0 */ 167 u8 len; /* size of this header + used digest bytes */ 168 u8 flags; 169 u8 digest_algo; /* FS_VERITY_HASH_ALG_* constant, 0 for no digest */ 170 u8 digest[FS_VERITY_MAX_DIGEST_SIZE]; /* Only the used part on disk */ 171 } __packed; 172 173 #define OVL_METACOPY_MAX_SIZE (sizeof(struct ovl_metacopy)) 174 #define OVL_METACOPY_MIN_SIZE (OVL_METACOPY_MAX_SIZE - FS_VERITY_MAX_DIGEST_SIZE) 175 #define OVL_METACOPY_INIT { 0, OVL_METACOPY_MIN_SIZE } 176 177 static inline int ovl_metadata_digest_size(const struct ovl_metacopy *metacopy) 178 { 179 if (metacopy->len < OVL_METACOPY_MIN_SIZE) 180 return 0; 181 return (int)metacopy->len - OVL_METACOPY_MIN_SIZE; 182 } 183 184 /* No atime modification on underlying */ 185 #define OVL_OPEN_FLAGS (O_NOATIME) 186 187 extern const char *const ovl_xattr_table[][2]; 188 static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) 189 { 190 return ovl_xattr_table[ox][ofs->config.userxattr]; 191 } 192 193 /* 194 * When changing ownership of an upper object map the intended ownership 195 * according to the upper layer's idmapping. When an upper mount idmaps files 196 * that are stored on-disk as owned by id 1001 to id 1000 this means stat on 197 * this object will report it as being owned by id 1000 when calling stat via 198 * the upper mount. 199 * In order to change ownership of an object so stat reports id 1000 when 200 * called on an idmapped upper mount the value written to disk - i.e., the 201 * value stored in ia_*id - must 1001. The mount mapping helper will thus take 202 * care to map 1000 to 1001. 203 * The mnt idmapping helpers are nops if the upper layer isn't idmapped. 204 */ 205 static inline int ovl_do_notify_change(struct ovl_fs *ofs, 206 struct dentry *upperdentry, 207 struct iattr *attr) 208 { 209 return notify_change(ovl_upper_mnt_idmap(ofs), upperdentry, attr, NULL); 210 } 211 212 static inline int ovl_do_rmdir(struct ovl_fs *ofs, 213 struct inode *dir, struct dentry *dentry) 214 { 215 int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL); 216 217 pr_debug("rmdir(%pd2) = %i\n", dentry, err); 218 return err; 219 } 220 221 static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir, 222 struct dentry *dentry) 223 { 224 int err = vfs_unlink(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL); 225 226 pr_debug("unlink(%pd2) = %i\n", dentry, err); 227 return err; 228 } 229 230 static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry, 231 struct inode *dir, struct dentry *new_dentry) 232 { 233 int err = vfs_link(old_dentry, ovl_upper_mnt_idmap(ofs), dir, 234 new_dentry, NULL); 235 236 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err); 237 return err; 238 } 239 240 static inline int ovl_do_create(struct ovl_fs *ofs, 241 struct inode *dir, struct dentry *dentry, 242 umode_t mode) 243 { 244 int err = vfs_create(ovl_upper_mnt_idmap(ofs), dentry, mode, NULL); 245 246 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); 247 return err; 248 } 249 250 static inline struct dentry *ovl_do_mkdir(struct ovl_fs *ofs, 251 struct inode *dir, 252 struct dentry *dentry, 253 umode_t mode) 254 { 255 struct dentry *ret; 256 257 ret = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, NULL); 258 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, PTR_ERR_OR_ZERO(ret)); 259 return ret; 260 } 261 262 static inline int ovl_do_mknod(struct ovl_fs *ofs, 263 struct inode *dir, struct dentry *dentry, 264 umode_t mode, dev_t dev) 265 { 266 int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev, NULL); 267 268 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); 269 return err; 270 } 271 272 static inline int ovl_do_symlink(struct ovl_fs *ofs, 273 struct inode *dir, struct dentry *dentry, 274 const char *oldname) 275 { 276 int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname, NULL); 277 278 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); 279 return err; 280 } 281 282 static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, 283 void *value, size_t size) 284 { 285 int err, len; 286 287 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb); 288 289 err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry, 290 name, value, size); 291 len = (value && err > 0) ? err : 0; 292 293 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", 294 path->dentry, name, min(len, 48), value, size, err); 295 return err; 296 } 297 298 static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, 299 struct dentry *upperdentry, 300 enum ovl_xattr ox, void *value, 301 size_t size) 302 { 303 struct path upperpath = { 304 .dentry = upperdentry, 305 .mnt = ovl_upper_mnt(ofs), 306 }; 307 308 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size); 309 } 310 311 static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, 312 const struct path *path, 313 enum ovl_xattr ox, void *value, 314 size_t size) 315 { 316 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size); 317 } 318 319 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 320 const char *name, const void *value, 321 size_t size, int flags) 322 { 323 int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name, 324 value, size, flags); 325 326 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n", 327 dentry, name, min((int)size, 48), value, size, flags, err); 328 return err; 329 } 330 331 static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 332 enum ovl_xattr ox, const void *value, 333 size_t size) 334 { 335 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0); 336 } 337 338 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 339 const char *name) 340 { 341 int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name); 342 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); 343 return err; 344 } 345 346 static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 347 enum ovl_xattr ox) 348 { 349 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox)); 350 } 351 352 static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, 353 const char *acl_name, struct posix_acl *acl) 354 { 355 return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl); 356 } 357 358 static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, 359 const char *acl_name) 360 { 361 return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name); 362 } 363 364 static inline int ovl_do_rename_rd(struct renamedata *rd) 365 { 366 int err; 367 368 pr_debug("rename(%pd2, %pd2, 0x%x)\n", rd->old_dentry, rd->new_dentry, 369 rd->flags); 370 err = vfs_rename(rd); 371 if (err) { 372 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 373 rd->old_dentry, rd->new_dentry, err); 374 } 375 return err; 376 } 377 378 static inline int ovl_do_rename(struct ovl_fs *ofs, struct dentry *olddir, 379 struct dentry *olddentry, struct dentry *newdir, 380 struct dentry *newdentry, unsigned int flags) 381 { 382 struct renamedata rd = { 383 .mnt_idmap = ovl_upper_mnt_idmap(ofs), 384 .old_parent = olddir, 385 .old_dentry = olddentry, 386 .new_parent = newdir, 387 .new_dentry = newdentry, 388 .flags = flags, 389 }; 390 391 return ovl_do_rename_rd(&rd); 392 } 393 394 static inline int ovl_do_whiteout(struct ovl_fs *ofs, 395 struct inode *dir, struct dentry *dentry) 396 { 397 int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry); 398 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 399 return err; 400 } 401 402 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, 403 struct dentry *dentry, umode_t mode) 404 { 405 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; 406 struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, 407 mode, O_LARGEFILE | O_WRONLY, 408 current_cred()); 409 int err = PTR_ERR_OR_ZERO(file); 410 411 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 412 return file; 413 } 414 415 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, 416 const char *name, 417 struct dentry *base, int len) 418 { 419 return lookup_one(ovl_upper_mnt_idmap(ofs), &QSTR_LEN(name, len), base); 420 } 421 422 static inline struct dentry *ovl_lookup_upper_unlocked(struct ovl_fs *ofs, 423 const char *name, 424 struct dentry *base, 425 int len) 426 { 427 return lookup_one_unlocked(ovl_upper_mnt_idmap(ofs), 428 &QSTR_LEN(name, len), base); 429 } 430 431 static inline struct dentry *ovl_start_creating_upper(struct ovl_fs *ofs, 432 struct dentry *parent, 433 struct qstr *name) 434 { 435 return start_creating(ovl_upper_mnt_idmap(ofs), 436 parent, name); 437 } 438 439 static inline struct dentry *ovl_start_removing_upper(struct ovl_fs *ofs, 440 struct dentry *parent, 441 struct qstr *name) 442 { 443 return start_removing(ovl_upper_mnt_idmap(ofs), 444 parent, name); 445 } 446 447 static inline bool ovl_open_flags_need_copy_up(int flags) 448 { 449 if (!flags) 450 return false; 451 452 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 453 } 454 455 /* util.c */ 456 int ovl_get_write_access(struct dentry *dentry); 457 void ovl_put_write_access(struct dentry *dentry); 458 void ovl_start_write(struct dentry *dentry); 459 void ovl_end_write(struct dentry *dentry); 460 int ovl_want_write(struct dentry *dentry); 461 void ovl_drop_write(struct dentry *dentry); 462 struct dentry *ovl_workdir(struct dentry *dentry); 463 const struct cred *ovl_override_creds(struct super_block *sb); 464 465 EXTEND_CLASS(override_creds, _ovl, ovl_override_creds(sb), struct super_block *sb) 466 467 #define with_ovl_creds(sb) \ 468 scoped_class(override_creds_ovl, __UNIQUE_ID(label), sb) 469 470 static inline const struct cred *ovl_creds(struct super_block *sb) 471 { 472 return OVL_FS(sb)->creator_cred; 473 } 474 475 int ovl_can_decode_fh(struct super_block *sb); 476 struct dentry *ovl_indexdir(struct super_block *sb); 477 bool ovl_index_all(struct super_block *sb); 478 bool ovl_verify_lower(struct super_block *sb); 479 struct ovl_path *ovl_stack_alloc(unsigned int n); 480 void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); 481 void ovl_stack_put(struct ovl_path *stack, unsigned int n); 482 void ovl_stack_free(struct ovl_path *stack, unsigned int n); 483 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 484 void ovl_free_entry(struct ovl_entry *oe); 485 bool ovl_dentry_remote(struct dentry *dentry); 486 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); 487 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, 488 struct ovl_entry *oe); 489 void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, 490 struct ovl_entry *oe, unsigned int mask); 491 bool ovl_dentry_weird(struct dentry *dentry); 492 493 static inline bool ovl_dentry_casefolded(struct dentry *dentry) 494 { 495 return sb_has_encoding(dentry->d_sb) && IS_CASEFOLDED(d_inode(dentry)); 496 } 497 498 enum ovl_path_type ovl_path_type(struct dentry *dentry); 499 void ovl_path_upper(struct dentry *dentry, struct path *path); 500 void ovl_path_lower(struct dentry *dentry, struct path *path); 501 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 502 struct inode *ovl_i_path_real(struct inode *inode, struct path *path); 503 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 504 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); 505 struct dentry *ovl_dentry_upper(struct dentry *dentry); 506 struct dentry *ovl_dentry_lower(struct dentry *dentry); 507 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 508 int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); 509 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); 510 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 511 struct dentry *ovl_dentry_real(struct dentry *dentry); 512 struct dentry *ovl_i_dentry_upper(struct inode *inode); 513 struct inode *ovl_inode_upper(struct inode *inode); 514 struct inode *ovl_inode_lower(struct inode *inode); 515 struct inode *ovl_inode_lowerdata(struct inode *inode); 516 struct inode *ovl_inode_real(struct inode *inode); 517 struct inode *ovl_inode_realdata(struct inode *inode); 518 const char *ovl_lowerdata_redirect(struct inode *inode); 519 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 520 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 521 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 522 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 523 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 524 bool ovl_dentry_is_opaque(struct dentry *dentry); 525 bool ovl_dentry_is_whiteout(struct dentry *dentry); 526 void ovl_dentry_set_opaque(struct dentry *dentry); 527 bool ovl_dentry_has_xwhiteouts(struct dentry *dentry); 528 void ovl_dentry_set_xwhiteouts(struct dentry *dentry); 529 void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs, 530 const struct ovl_layer *layer); 531 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 532 void ovl_dentry_set_upper_alias(struct dentry *dentry); 533 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 534 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 535 bool ovl_has_upperdata(struct inode *inode); 536 void ovl_set_upperdata(struct inode *inode); 537 const char *ovl_dentry_get_redirect(struct dentry *dentry); 538 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 539 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 540 void ovl_dir_modified(struct dentry *dentry, bool impurity); 541 u64 ovl_inode_version_get(struct inode *inode); 542 bool ovl_is_whiteout(struct dentry *dentry); 543 bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); 544 struct file *ovl_path_open(const struct path *path, int flags); 545 int ovl_copy_up_start(struct dentry *dentry, int flags); 546 void ovl_copy_up_end(struct dentry *dentry); 547 bool ovl_already_copied_up(struct dentry *dentry, int flags); 548 char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path, 549 enum ovl_xattr ox); 550 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); 551 bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path); 552 bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, 553 const struct path *upperpath); 554 555 static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs, 556 struct dentry *upperdentry) 557 { 558 struct path upperpath = { 559 .dentry = upperdentry, 560 .mnt = ovl_upper_mnt(ofs), 561 }; 562 return ovl_path_is_whiteout(ofs, &upperpath); 563 } 564 565 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, 566 struct dentry *upperdentry) 567 { 568 struct path upperpath = { 569 .dentry = upperdentry, 570 .mnt = ovl_upper_mnt(ofs), 571 }; 572 return ovl_path_check_origin_xattr(ofs, &upperpath); 573 } 574 575 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 576 enum ovl_xattr ox, const void *value, size_t size, 577 int xerr); 578 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 579 bool ovl_inuse_trylock(struct dentry *dentry); 580 void ovl_inuse_unlock(struct dentry *dentry); 581 bool ovl_is_inuse(struct dentry *dentry); 582 bool ovl_need_index(struct dentry *dentry); 583 int ovl_nlink_start(struct dentry *dentry); 584 void ovl_nlink_end(struct dentry *dentry); 585 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *work, 586 struct dentry *upperdir, struct dentry *upper); 587 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path, 588 struct ovl_metacopy *data); 589 int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d, 590 struct ovl_metacopy *metacopy); 591 bool ovl_is_metacopy_dentry(struct dentry *dentry); 592 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); 593 int ovl_ensure_verity_loaded(const struct path *path); 594 int ovl_validate_verity(struct ovl_fs *ofs, 595 const struct path *metapath, 596 const struct path *datapath); 597 int ovl_get_verity_digest(struct ovl_fs *ofs, const struct path *src, 598 struct ovl_metacopy *metacopy); 599 int ovl_sync_status(struct ovl_fs *ofs); 600 601 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 602 { 603 set_bit(flag, &OVL_I(inode)->flags); 604 } 605 606 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 607 { 608 clear_bit(flag, &OVL_I(inode)->flags); 609 } 610 611 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 612 { 613 return test_bit(flag, &OVL_I(inode)->flags); 614 } 615 616 static inline bool ovl_is_impuredir(struct super_block *sb, 617 struct dentry *upperdentry) 618 { 619 struct ovl_fs *ofs = OVL_FS(sb); 620 struct path upperpath = { 621 .dentry = upperdentry, 622 .mnt = ovl_upper_mnt(ofs), 623 }; 624 625 return ovl_get_dir_xattr_val(ofs, &upperpath, OVL_XATTR_IMPURE) == 'y'; 626 } 627 628 static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs, 629 const struct path *path) 630 { 631 return ovl_get_dir_xattr_val(ofs, path, OVL_XATTR_OPAQUE); 632 } 633 634 static inline bool ovl_redirect_follow(struct ovl_fs *ofs) 635 { 636 return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW; 637 } 638 639 static inline bool ovl_redirect_dir(struct ovl_fs *ofs) 640 { 641 return ofs->config.redirect_mode == OVL_REDIRECT_ON; 642 } 643 644 static inline bool ovl_origin_uuid(struct ovl_fs *ofs) 645 { 646 return ofs->config.uuid != OVL_UUID_OFF; 647 } 648 649 static inline bool ovl_has_fsid(struct ovl_fs *ofs) 650 { 651 return ofs->config.uuid == OVL_UUID_ON || 652 ofs->config.uuid == OVL_UUID_AUTO; 653 } 654 655 /* 656 * With xino=auto, we do best effort to keep all inodes on same st_dev and 657 * d_ino consistent with st_ino. 658 * With xino=on, we do the same effort but we warn if we failed. 659 */ 660 static inline bool ovl_xino_warn(struct ovl_fs *ofs) 661 { 662 return ofs->config.xino == OVL_XINO_ON; 663 } 664 665 static inline bool ovl_should_sync(struct ovl_fs *ofs) 666 { 667 return ofs->config.fsync_mode != OVL_FSYNC_VOLATILE; 668 } 669 670 static inline bool ovl_should_sync_metadata(struct ovl_fs *ofs) 671 { 672 return ofs->config.fsync_mode == OVL_FSYNC_STRICT; 673 } 674 675 static inline bool ovl_is_volatile(struct ovl_config *config) 676 { 677 return config->fsync_mode == OVL_FSYNC_VOLATILE; 678 } 679 680 /* 681 * To avoid regressions in existing setups with overlay lower offline changes, 682 * we allow lower changes only if none of the new features are used. 683 */ 684 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 685 { 686 return (!ofs->config.index && !ofs->config.metacopy && 687 !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs)); 688 } 689 690 /* All layers on same fs? */ 691 static inline bool ovl_same_fs(struct ovl_fs *ofs) 692 { 693 return ofs->xino_mode == 0; 694 } 695 696 /* All overlay inodes have same st_dev? */ 697 static inline bool ovl_same_dev(struct ovl_fs *ofs) 698 { 699 return ofs->xino_mode >= 0; 700 } 701 702 static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) 703 { 704 return ovl_same_dev(ofs) ? ofs->xino_mode : 0; 705 } 706 707 static inline void ovl_inode_lock(struct inode *inode) 708 { 709 mutex_lock(&OVL_I(inode)->lock); 710 } 711 712 static inline int ovl_inode_lock_interruptible(struct inode *inode) 713 { 714 return mutex_lock_interruptible(&OVL_I(inode)->lock); 715 } 716 717 static inline void ovl_inode_unlock(struct inode *inode) 718 { 719 mutex_unlock(&OVL_I(inode)->lock); 720 } 721 722 723 /* namei.c */ 724 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 725 726 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 727 { 728 if (fh_len < sizeof(struct ovl_fh)) 729 return -EINVAL; 730 731 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 732 } 733 734 bool ovl_uuid_match(struct ovl_fs *ofs, const struct super_block *sb, 735 const uuid_t *uuid); 736 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 737 struct vfsmount *mnt, bool connected); 738 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 739 struct dentry *upperdentry, struct ovl_path **stackp); 740 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 741 enum ovl_xattr ox, const struct ovl_fh *fh, 742 bool is_upper, bool set); 743 int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry, 744 enum ovl_xattr ox, struct dentry *real, 745 bool is_upper, bool set); 746 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, 747 bool connected); 748 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 749 int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name); 750 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 751 struct qstr *name); 752 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 753 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 754 struct dentry *origin, bool verify); 755 int ovl_path_next(int idx, struct dentry *dentry, struct path *path, 756 const struct ovl_layer **layer); 757 int ovl_verify_lowerdata(struct dentry *dentry); 758 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 759 unsigned int flags); 760 bool ovl_lower_positive(struct dentry *dentry); 761 762 static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper, 763 const struct ovl_fh *fh, bool set) 764 { 765 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, fh, false, set); 766 } 767 768 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 769 struct dentry *origin, bool set) 770 { 771 return ovl_verify_origin_xattr(ofs, upper, OVL_XATTR_ORIGIN, origin, 772 false, set); 773 } 774 775 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 776 struct dentry *upper, bool set) 777 { 778 return ovl_verify_origin_xattr(ofs, index, OVL_XATTR_UPPER, upper, 779 true, set); 780 } 781 782 /* readdir.c */ 783 extern const struct file_operations ovl_dir_operations; 784 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 785 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 786 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 787 struct list_head *list); 788 void ovl_cache_free(struct list_head *list); 789 void ovl_dir_cache_free(struct inode *inode); 790 int ovl_check_d_type_supported(const struct path *realpath); 791 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct dentry *parent, 792 struct vfsmount *mnt, struct dentry *dentry, int level); 793 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 794 795 /* 796 * Can we iterate real dir directly? 797 * 798 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 799 * lower dir was removed under it and possibly before it was rotated from upper 800 * to lower layer. 801 */ 802 static inline bool ovl_dir_is_real(struct inode *dir) 803 { 804 return !ovl_test_flag(OVL_WHITEOUTS, dir); 805 } 806 807 /* inode.c */ 808 int ovl_set_nlink_upper(struct dentry *dentry); 809 int ovl_set_nlink_lower(struct dentry *dentry); 810 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 811 struct dentry *upperdentry, 812 unsigned int fallback); 813 int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, 814 int mask); 815 816 #ifdef CONFIG_FS_POSIX_ACL 817 struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, 818 struct inode *inode, int type, 819 bool rcu, bool noperm); 820 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, 821 bool rcu) 822 { 823 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true); 824 } 825 static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, 826 struct dentry *dentry, int type) 827 { 828 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false); 829 } 830 int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 831 struct posix_acl *acl, int type); 832 struct posix_acl *ovl_get_acl_path(const struct path *path, 833 const char *acl_name, bool noperm); 834 #else 835 #define ovl_get_inode_acl NULL 836 #define ovl_get_acl NULL 837 #define ovl_set_acl NULL 838 static inline struct posix_acl *ovl_get_acl_path(const struct path *path, 839 const char *acl_name, 840 bool noperm) 841 { 842 return NULL; 843 } 844 #endif 845 846 int ovl_update_time(struct inode *inode, enum fs_update_time type, 847 unsigned int flags); 848 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 849 850 struct ovl_inode_params { 851 struct inode *newinode; 852 struct dentry *upperdentry; 853 struct ovl_entry *oe; 854 bool index; 855 char *redirect; 856 char *lowerdata_redirect; 857 }; 858 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 859 unsigned long ino, int fsid); 860 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 861 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 862 bool is_upper); 863 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 864 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 865 struct inode *ovl_get_inode(struct super_block *sb, 866 struct ovl_inode_params *oip); 867 void ovl_copyattr(struct inode *to); 868 869 /* vfs fileattr flags read from overlay.protattr xattr to ovl inode */ 870 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 871 /* vfs fileattr flags copied from real to ovl inode */ 872 #define OVL_FATTR_I_FLAGS_MASK (OVL_PROT_I_FLAGS_MASK | S_SYNC | S_NOATIME) 873 /* vfs inode flags copied from real to ovl inode */ 874 #define OVL_COPY_I_FLAGS_MASK (OVL_FATTR_I_FLAGS_MASK | S_CASEFOLD) 875 876 /* 877 * fileattr flags copied from lower to upper inode on copy up. 878 * We cannot copy up immutable/append-only flags, because that would prevent 879 * linking temp inode to upper dir, so we store them in xattr instead. 880 */ 881 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 882 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 883 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 884 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 885 886 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 887 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 888 struct file_kattr *fa); 889 890 static inline void ovl_copyflags(struct inode *from, struct inode *to) 891 { 892 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 893 894 inode_set_flags(to, from->i_flags & mask, mask); 895 } 896 897 /* dir.c */ 898 extern const struct inode_operations ovl_dir_inode_operations; 899 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct dentry *dir, 900 struct dentry *dentry); 901 struct ovl_cattr { 902 dev_t rdev; 903 umode_t mode; 904 const char *link; 905 struct dentry *hardlink; 906 }; 907 908 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 909 910 struct dentry *ovl_create_real(struct ovl_fs *ofs, 911 struct dentry *parent, struct dentry *newdentry, 912 struct ovl_cattr *attr); 913 int ovl_cleanup(struct ovl_fs *ofs, struct dentry *workdir, struct dentry *dentry); 914 #define OVL_TEMPNAME_SIZE 20 915 void ovl_tempname(char name[OVL_TEMPNAME_SIZE]); 916 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, 917 struct ovl_cattr *attr); 918 919 /* file.c */ 920 extern const struct file_operations ovl_file_operations; 921 int ovl_real_fileattr_get(const struct path *realpath, struct file_kattr *fa); 922 int ovl_real_fileattr_set(const struct path *realpath, struct file_kattr *fa); 923 int ovl_fileattr_get(struct dentry *dentry, struct file_kattr *fa); 924 int ovl_fileattr_set(struct mnt_idmap *idmap, 925 struct dentry *dentry, struct file_kattr *fa); 926 struct ovl_file; 927 struct ovl_file *ovl_file_alloc(struct file *realfile); 928 void ovl_file_free(struct ovl_file *of); 929 930 /* copy_up.c */ 931 int ovl_copy_up(struct dentry *dentry); 932 int ovl_copy_up_with_data(struct dentry *dentry); 933 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 934 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); 935 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); 936 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct inode *realinode, 937 bool is_upper); 938 struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin); 939 int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh, 940 struct dentry *upper); 941 942 /* export.c */ 943 extern const struct export_operations ovl_export_operations; 944 extern const struct export_operations ovl_export_fid_operations; 945 946 /* super.c */ 947 int ovl_fill_super(struct super_block *sb, struct fs_context *fc); 948 949 /* Will this overlay be forced to mount/remount ro? */ 950 static inline bool ovl_force_readonly(struct ovl_fs *ofs) 951 { 952 return (!ovl_upper_mnt(ofs) || !ofs->workdir); 953 } 954 955 /* xattr.c */ 956 957 const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs); 958 int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 959 struct iattr *attr); 960 int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, 961 struct kstat *stat, u32 request_mask, unsigned int flags); 962 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 963