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 OVL_XATTR_XWHITEOUTS, 54 }; 55 56 enum ovl_inode_flag { 57 /* Pure upper dir that may contain non pure upper entries */ 58 OVL_IMPURE, 59 /* Non-merge dir that may contain whiteout entries */ 60 OVL_WHITEOUTS, 61 OVL_INDEX, 62 OVL_UPPERDATA, 63 /* Inode number will remain constant over copy up. */ 64 OVL_CONST_INO, 65 OVL_HAS_DIGEST, 66 OVL_VERIFIED_DIGEST, 67 }; 68 69 enum ovl_entry_flag { 70 OVL_E_UPPER_ALIAS, 71 OVL_E_OPAQUE, 72 OVL_E_CONNECTED, 73 }; 74 75 enum { 76 OVL_REDIRECT_OFF, /* "off" mode is never used. In effect */ 77 OVL_REDIRECT_FOLLOW, /* ...it translates to either "follow" */ 78 OVL_REDIRECT_NOFOLLOW, /* ...or "nofollow". */ 79 OVL_REDIRECT_ON, 80 }; 81 82 enum { 83 OVL_UUID_OFF, 84 OVL_UUID_NULL, 85 OVL_UUID_AUTO, 86 OVL_UUID_ON, 87 }; 88 89 enum { 90 OVL_XINO_OFF, 91 OVL_XINO_AUTO, 92 OVL_XINO_ON, 93 }; 94 95 enum { 96 OVL_VERITY_OFF, 97 OVL_VERITY_ON, 98 OVL_VERITY_REQUIRE, 99 }; 100 101 /* 102 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin, 103 * where: 104 * origin.fh - exported file handle of the lower file 105 * origin.uuid - uuid of the lower filesystem 106 */ 107 #define OVL_FH_VERSION 0 108 #define OVL_FH_MAGIC 0xfb 109 110 /* CPU byte order required for fid decoding: */ 111 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0) 112 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1) 113 /* Is the real inode encoded in fid an upper inode? */ 114 #define OVL_FH_FLAG_PATH_UPPER (1 << 2) 115 116 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \ 117 OVL_FH_FLAG_PATH_UPPER) 118 119 #if defined(__LITTLE_ENDIAN) 120 #define OVL_FH_FLAG_CPU_ENDIAN 0 121 #elif defined(__BIG_ENDIAN) 122 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN 123 #else 124 #error Endianness not defined 125 #endif 126 127 /* The type used to be returned by overlay exportfs for misaligned fid */ 128 #define OVL_FILEID_V0 0xfb 129 /* The type returned by overlay exportfs for 32bit aligned fid */ 130 #define OVL_FILEID_V1 0xf8 131 132 /* On-disk format for "origin" file handle */ 133 struct ovl_fb { 134 u8 version; /* 0 */ 135 u8 magic; /* 0xfb */ 136 u8 len; /* size of this header + size of fid */ 137 u8 flags; /* OVL_FH_FLAG_* */ 138 u8 type; /* fid_type of fid */ 139 uuid_t uuid; /* uuid of filesystem */ 140 u32 fid[]; /* file identifier should be 32bit aligned in-memory */ 141 } __packed; 142 143 /* In-memory and on-wire format for overlay file handle */ 144 struct ovl_fh { 145 u8 padding[3]; /* make sure fb.fid is 32bit aligned */ 146 union { 147 struct ovl_fb fb; 148 DECLARE_FLEX_ARRAY(u8, buf); 149 }; 150 } __packed; 151 152 #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb) 153 #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len) 154 #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \ 155 offsetof(struct ovl_fb, fid)) 156 157 /* On-disk format for "metacopy" xattr (if non-zero size) */ 158 struct ovl_metacopy { 159 u8 version; /* 0 */ 160 u8 len; /* size of this header + used digest bytes */ 161 u8 flags; 162 u8 digest_algo; /* FS_VERITY_HASH_ALG_* constant, 0 for no digest */ 163 u8 digest[FS_VERITY_MAX_DIGEST_SIZE]; /* Only the used part on disk */ 164 } __packed; 165 166 #define OVL_METACOPY_MAX_SIZE (sizeof(struct ovl_metacopy)) 167 #define OVL_METACOPY_MIN_SIZE (OVL_METACOPY_MAX_SIZE - FS_VERITY_MAX_DIGEST_SIZE) 168 #define OVL_METACOPY_INIT { 0, OVL_METACOPY_MIN_SIZE } 169 170 static inline int ovl_metadata_digest_size(const struct ovl_metacopy *metacopy) 171 { 172 if (metacopy->len < OVL_METACOPY_MIN_SIZE) 173 return 0; 174 return (int)metacopy->len - OVL_METACOPY_MIN_SIZE; 175 } 176 177 extern const char *const ovl_xattr_table[][2]; 178 static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) 179 { 180 return ovl_xattr_table[ox][ofs->config.userxattr]; 181 } 182 183 /* 184 * When changing ownership of an upper object map the intended ownership 185 * according to the upper layer's idmapping. When an upper mount idmaps files 186 * that are stored on-disk as owned by id 1001 to id 1000 this means stat on 187 * this object will report it as being owned by id 1000 when calling stat via 188 * the upper mount. 189 * In order to change ownership of an object so stat reports id 1000 when 190 * called on an idmapped upper mount the value written to disk - i.e., the 191 * value stored in ia_*id - must 1001. The mount mapping helper will thus take 192 * care to map 1000 to 1001. 193 * The mnt idmapping helpers are nops if the upper layer isn't idmapped. 194 */ 195 static inline int ovl_do_notify_change(struct ovl_fs *ofs, 196 struct dentry *upperdentry, 197 struct iattr *attr) 198 { 199 return notify_change(ovl_upper_mnt_idmap(ofs), upperdentry, attr, NULL); 200 } 201 202 static inline int ovl_do_rmdir(struct ovl_fs *ofs, 203 struct inode *dir, struct dentry *dentry) 204 { 205 int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry); 206 207 pr_debug("rmdir(%pd2) = %i\n", dentry, err); 208 return err; 209 } 210 211 static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir, 212 struct dentry *dentry) 213 { 214 int err = vfs_unlink(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL); 215 216 pr_debug("unlink(%pd2) = %i\n", dentry, err); 217 return err; 218 } 219 220 static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry, 221 struct inode *dir, struct dentry *new_dentry) 222 { 223 int err = vfs_link(old_dentry, ovl_upper_mnt_idmap(ofs), dir, 224 new_dentry, NULL); 225 226 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err); 227 return err; 228 } 229 230 static inline int ovl_do_create(struct ovl_fs *ofs, 231 struct inode *dir, struct dentry *dentry, 232 umode_t mode) 233 { 234 int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true); 235 236 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); 237 return err; 238 } 239 240 static inline int ovl_do_mkdir(struct ovl_fs *ofs, 241 struct inode *dir, struct dentry *dentry, 242 umode_t mode) 243 { 244 int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode); 245 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err); 246 return err; 247 } 248 249 static inline int ovl_do_mknod(struct ovl_fs *ofs, 250 struct inode *dir, struct dentry *dentry, 251 umode_t mode, dev_t dev) 252 { 253 int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev); 254 255 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); 256 return err; 257 } 258 259 static inline int ovl_do_symlink(struct ovl_fs *ofs, 260 struct inode *dir, struct dentry *dentry, 261 const char *oldname) 262 { 263 int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname); 264 265 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); 266 return err; 267 } 268 269 static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, 270 void *value, size_t size) 271 { 272 int err, len; 273 274 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb); 275 276 err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry, 277 name, value, size); 278 len = (value && err > 0) ? err : 0; 279 280 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", 281 path->dentry, name, min(len, 48), value, size, err); 282 return err; 283 } 284 285 static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, 286 struct dentry *upperdentry, 287 enum ovl_xattr ox, void *value, 288 size_t size) 289 { 290 struct path upperpath = { 291 .dentry = upperdentry, 292 .mnt = ovl_upper_mnt(ofs), 293 }; 294 295 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size); 296 } 297 298 static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, 299 const struct path *path, 300 enum ovl_xattr ox, void *value, 301 size_t size) 302 { 303 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size); 304 } 305 306 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 307 const char *name, const void *value, 308 size_t size, int flags) 309 { 310 int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name, 311 value, size, flags); 312 313 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n", 314 dentry, name, min((int)size, 48), value, size, flags, err); 315 return err; 316 } 317 318 static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 319 enum ovl_xattr ox, const void *value, 320 size_t size) 321 { 322 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0); 323 } 324 325 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 326 const char *name) 327 { 328 int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name); 329 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); 330 return err; 331 } 332 333 static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 334 enum ovl_xattr ox) 335 { 336 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox)); 337 } 338 339 static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, 340 const char *acl_name, struct posix_acl *acl) 341 { 342 return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl); 343 } 344 345 static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, 346 const char *acl_name) 347 { 348 return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name); 349 } 350 351 static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir, 352 struct dentry *olddentry, struct inode *newdir, 353 struct dentry *newdentry, unsigned int flags) 354 { 355 int err; 356 struct renamedata rd = { 357 .old_mnt_idmap = ovl_upper_mnt_idmap(ofs), 358 .old_dir = olddir, 359 .old_dentry = olddentry, 360 .new_mnt_idmap = ovl_upper_mnt_idmap(ofs), 361 .new_dir = newdir, 362 .new_dentry = newdentry, 363 .flags = flags, 364 }; 365 366 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags); 367 err = vfs_rename(&rd); 368 if (err) { 369 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 370 olddentry, newdentry, err); 371 } 372 return err; 373 } 374 375 static inline int ovl_do_whiteout(struct ovl_fs *ofs, 376 struct inode *dir, struct dentry *dentry) 377 { 378 int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry); 379 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 380 return err; 381 } 382 383 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, 384 struct dentry *dentry, umode_t mode) 385 { 386 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; 387 struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, 388 mode, O_LARGEFILE | O_WRONLY, 389 current_cred()); 390 int err = PTR_ERR_OR_ZERO(file); 391 392 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 393 return file; 394 } 395 396 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, 397 const char *name, 398 struct dentry *base, int len) 399 { 400 return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len); 401 } 402 403 static inline bool ovl_open_flags_need_copy_up(int flags) 404 { 405 if (!flags) 406 return false; 407 408 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 409 } 410 411 static inline int ovl_do_getattr(const struct path *path, struct kstat *stat, 412 u32 request_mask, unsigned int flags) 413 { 414 if (flags & AT_GETATTR_NOSEC) 415 return vfs_getattr_nosec(path, stat, request_mask, flags); 416 return vfs_getattr(path, stat, request_mask, flags); 417 } 418 419 /* util.c */ 420 int ovl_get_write_access(struct dentry *dentry); 421 void ovl_put_write_access(struct dentry *dentry); 422 void ovl_start_write(struct dentry *dentry); 423 void ovl_end_write(struct dentry *dentry); 424 int ovl_want_write(struct dentry *dentry); 425 void ovl_drop_write(struct dentry *dentry); 426 struct dentry *ovl_workdir(struct dentry *dentry); 427 const struct cred *ovl_override_creds(struct super_block *sb); 428 429 static inline const struct cred *ovl_creds(struct super_block *sb) 430 { 431 return OVL_FS(sb)->creator_cred; 432 } 433 434 int ovl_can_decode_fh(struct super_block *sb); 435 struct dentry *ovl_indexdir(struct super_block *sb); 436 bool ovl_index_all(struct super_block *sb); 437 bool ovl_verify_lower(struct super_block *sb); 438 struct ovl_path *ovl_stack_alloc(unsigned int n); 439 void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); 440 void ovl_stack_put(struct ovl_path *stack, unsigned int n); 441 void ovl_stack_free(struct ovl_path *stack, unsigned int n); 442 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 443 void ovl_free_entry(struct ovl_entry *oe); 444 bool ovl_dentry_remote(struct dentry *dentry); 445 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); 446 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, 447 struct ovl_entry *oe); 448 void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, 449 struct ovl_entry *oe, unsigned int mask); 450 bool ovl_dentry_weird(struct dentry *dentry); 451 enum ovl_path_type ovl_path_type(struct dentry *dentry); 452 void ovl_path_upper(struct dentry *dentry, struct path *path); 453 void ovl_path_lower(struct dentry *dentry, struct path *path); 454 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 455 struct inode *ovl_i_path_real(struct inode *inode, struct path *path); 456 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 457 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); 458 struct dentry *ovl_dentry_upper(struct dentry *dentry); 459 struct dentry *ovl_dentry_lower(struct dentry *dentry); 460 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 461 int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); 462 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); 463 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 464 struct dentry *ovl_dentry_real(struct dentry *dentry); 465 struct dentry *ovl_i_dentry_upper(struct inode *inode); 466 struct inode *ovl_inode_upper(struct inode *inode); 467 struct inode *ovl_inode_lower(struct inode *inode); 468 struct inode *ovl_inode_lowerdata(struct inode *inode); 469 struct inode *ovl_inode_real(struct inode *inode); 470 struct inode *ovl_inode_realdata(struct inode *inode); 471 const char *ovl_lowerdata_redirect(struct inode *inode); 472 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 473 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 474 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 475 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 476 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 477 bool ovl_dentry_is_opaque(struct dentry *dentry); 478 bool ovl_dentry_is_whiteout(struct dentry *dentry); 479 void ovl_dentry_set_opaque(struct dentry *dentry); 480 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 481 void ovl_dentry_set_upper_alias(struct dentry *dentry); 482 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 483 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 484 bool ovl_has_upperdata(struct inode *inode); 485 void ovl_set_upperdata(struct inode *inode); 486 const char *ovl_dentry_get_redirect(struct dentry *dentry); 487 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 488 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 489 void ovl_dir_modified(struct dentry *dentry, bool impurity); 490 u64 ovl_inode_version_get(struct inode *inode); 491 bool ovl_is_whiteout(struct dentry *dentry); 492 bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); 493 struct file *ovl_path_open(const struct path *path, int flags); 494 int ovl_copy_up_start(struct dentry *dentry, int flags); 495 void ovl_copy_up_end(struct dentry *dentry); 496 bool ovl_already_copied_up(struct dentry *dentry, int flags); 497 bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, 498 enum ovl_xattr ox); 499 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); 500 bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path); 501 bool ovl_path_check_xwhiteouts_xattr(struct ovl_fs *ofs, const struct path *path); 502 bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, 503 const struct path *upperpath); 504 505 static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs, 506 struct dentry *upperdentry) 507 { 508 struct path upperpath = { 509 .dentry = upperdentry, 510 .mnt = ovl_upper_mnt(ofs), 511 }; 512 return ovl_path_is_whiteout(ofs, &upperpath); 513 } 514 515 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, 516 struct dentry *upperdentry) 517 { 518 struct path upperpath = { 519 .dentry = upperdentry, 520 .mnt = ovl_upper_mnt(ofs), 521 }; 522 return ovl_path_check_origin_xattr(ofs, &upperpath); 523 } 524 525 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 526 enum ovl_xattr ox, const void *value, size_t size, 527 int xerr); 528 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 529 bool ovl_inuse_trylock(struct dentry *dentry); 530 void ovl_inuse_unlock(struct dentry *dentry); 531 bool ovl_is_inuse(struct dentry *dentry); 532 bool ovl_need_index(struct dentry *dentry); 533 int ovl_nlink_start(struct dentry *dentry); 534 void ovl_nlink_end(struct dentry *dentry); 535 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); 536 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path, 537 struct ovl_metacopy *data); 538 int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d, 539 struct ovl_metacopy *metacopy); 540 bool ovl_is_metacopy_dentry(struct dentry *dentry); 541 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); 542 int ovl_ensure_verity_loaded(struct path *path); 543 int ovl_get_verity_xattr(struct ovl_fs *ofs, const struct path *path, 544 u8 *digest_buf, int *buf_length); 545 int ovl_validate_verity(struct ovl_fs *ofs, 546 struct path *metapath, 547 struct path *datapath); 548 int ovl_get_verity_digest(struct ovl_fs *ofs, struct path *src, 549 struct ovl_metacopy *metacopy); 550 int ovl_sync_status(struct ovl_fs *ofs); 551 552 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 553 { 554 set_bit(flag, &OVL_I(inode)->flags); 555 } 556 557 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 558 { 559 clear_bit(flag, &OVL_I(inode)->flags); 560 } 561 562 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 563 { 564 return test_bit(flag, &OVL_I(inode)->flags); 565 } 566 567 static inline bool ovl_is_impuredir(struct super_block *sb, 568 struct dentry *upperdentry) 569 { 570 struct ovl_fs *ofs = OVL_FS(sb); 571 struct path upperpath = { 572 .dentry = upperdentry, 573 .mnt = ovl_upper_mnt(ofs), 574 }; 575 576 return ovl_path_check_dir_xattr(ofs, &upperpath, OVL_XATTR_IMPURE); 577 } 578 579 static inline bool ovl_redirect_follow(struct ovl_fs *ofs) 580 { 581 return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW; 582 } 583 584 static inline bool ovl_redirect_dir(struct ovl_fs *ofs) 585 { 586 return ofs->config.redirect_mode == OVL_REDIRECT_ON; 587 } 588 589 static inline bool ovl_origin_uuid(struct ovl_fs *ofs) 590 { 591 return ofs->config.uuid != OVL_UUID_OFF; 592 } 593 594 static inline bool ovl_has_fsid(struct ovl_fs *ofs) 595 { 596 return ofs->config.uuid == OVL_UUID_ON || 597 ofs->config.uuid == OVL_UUID_AUTO; 598 } 599 600 /* 601 * With xino=auto, we do best effort to keep all inodes on same st_dev and 602 * d_ino consistent with st_ino. 603 * With xino=on, we do the same effort but we warn if we failed. 604 */ 605 static inline bool ovl_xino_warn(struct ovl_fs *ofs) 606 { 607 return ofs->config.xino == OVL_XINO_ON; 608 } 609 610 /* 611 * To avoid regressions in existing setups with overlay lower offline changes, 612 * we allow lower changes only if none of the new features are used. 613 */ 614 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 615 { 616 return (!ofs->config.index && !ofs->config.metacopy && 617 !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs)); 618 } 619 620 /* All layers on same fs? */ 621 static inline bool ovl_same_fs(struct ovl_fs *ofs) 622 { 623 return ofs->xino_mode == 0; 624 } 625 626 /* All overlay inodes have same st_dev? */ 627 static inline bool ovl_same_dev(struct ovl_fs *ofs) 628 { 629 return ofs->xino_mode >= 0; 630 } 631 632 static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) 633 { 634 return ovl_same_dev(ofs) ? ofs->xino_mode : 0; 635 } 636 637 static inline void ovl_inode_lock(struct inode *inode) 638 { 639 mutex_lock(&OVL_I(inode)->lock); 640 } 641 642 static inline int ovl_inode_lock_interruptible(struct inode *inode) 643 { 644 return mutex_lock_interruptible(&OVL_I(inode)->lock); 645 } 646 647 static inline void ovl_inode_unlock(struct inode *inode) 648 { 649 mutex_unlock(&OVL_I(inode)->lock); 650 } 651 652 653 /* namei.c */ 654 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 655 656 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 657 { 658 if (fh_len < sizeof(struct ovl_fh)) 659 return -EINVAL; 660 661 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 662 } 663 664 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 665 struct vfsmount *mnt, bool connected); 666 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 667 struct dentry *upperdentry, struct ovl_path **stackp); 668 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 669 enum ovl_xattr ox, const struct ovl_fh *fh, 670 bool is_upper, bool set); 671 int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry, 672 enum ovl_xattr ox, struct dentry *real, 673 bool is_upper, bool set); 674 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, 675 bool connected); 676 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 677 int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name); 678 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 679 struct qstr *name); 680 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 681 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 682 struct dentry *origin, bool verify); 683 int ovl_path_next(int idx, struct dentry *dentry, struct path *path); 684 int ovl_verify_lowerdata(struct dentry *dentry); 685 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 686 unsigned int flags); 687 bool ovl_lower_positive(struct dentry *dentry); 688 689 static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper, 690 const struct ovl_fh *fh, bool set) 691 { 692 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, fh, false, set); 693 } 694 695 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 696 struct dentry *origin, bool set) 697 { 698 return ovl_verify_origin_xattr(ofs, upper, OVL_XATTR_ORIGIN, origin, 699 false, set); 700 } 701 702 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 703 struct dentry *upper, bool set) 704 { 705 return ovl_verify_origin_xattr(ofs, index, OVL_XATTR_UPPER, upper, 706 true, set); 707 } 708 709 /* readdir.c */ 710 extern const struct file_operations ovl_dir_operations; 711 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 712 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 713 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 714 struct list_head *list); 715 void ovl_cache_free(struct list_head *list); 716 void ovl_dir_cache_free(struct inode *inode); 717 int ovl_check_d_type_supported(const struct path *realpath); 718 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir, 719 struct vfsmount *mnt, struct dentry *dentry, int level); 720 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 721 722 /* 723 * Can we iterate real dir directly? 724 * 725 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 726 * lower dir was removed under it and possibly before it was rotated from upper 727 * to lower layer. 728 */ 729 static inline bool ovl_dir_is_real(struct inode *dir) 730 { 731 return !ovl_test_flag(OVL_WHITEOUTS, dir); 732 } 733 734 /* inode.c */ 735 int ovl_set_nlink_upper(struct dentry *dentry); 736 int ovl_set_nlink_lower(struct dentry *dentry); 737 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 738 struct dentry *upperdentry, 739 unsigned int fallback); 740 int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, 741 int mask); 742 743 #ifdef CONFIG_FS_POSIX_ACL 744 struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, 745 struct inode *inode, int type, 746 bool rcu, bool noperm); 747 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, 748 bool rcu) 749 { 750 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true); 751 } 752 static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, 753 struct dentry *dentry, int type) 754 { 755 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false); 756 } 757 int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 758 struct posix_acl *acl, int type); 759 struct posix_acl *ovl_get_acl_path(const struct path *path, 760 const char *acl_name, bool noperm); 761 #else 762 #define ovl_get_inode_acl NULL 763 #define ovl_get_acl NULL 764 #define ovl_set_acl NULL 765 static inline struct posix_acl *ovl_get_acl_path(const struct path *path, 766 const char *acl_name, 767 bool noperm) 768 { 769 return NULL; 770 } 771 #endif 772 773 int ovl_update_time(struct inode *inode, int flags); 774 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 775 776 struct ovl_inode_params { 777 struct inode *newinode; 778 struct dentry *upperdentry; 779 struct ovl_entry *oe; 780 bool index; 781 char *redirect; 782 char *lowerdata_redirect; 783 }; 784 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 785 unsigned long ino, int fsid); 786 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 787 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 788 bool is_upper); 789 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 790 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 791 struct inode *ovl_get_inode(struct super_block *sb, 792 struct ovl_inode_params *oip); 793 void ovl_copyattr(struct inode *to); 794 795 /* vfs inode flags copied from real to ovl inode */ 796 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE) 797 /* vfs inode flags read from overlay.protattr xattr to ovl inode */ 798 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 799 800 /* 801 * fileattr flags copied from lower to upper inode on copy up. 802 * We cannot copy up immutable/append-only flags, because that would prevent 803 * linking temp inode to upper dir, so we store them in xattr instead. 804 */ 805 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 806 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 807 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 808 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 809 810 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 811 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 812 struct fileattr *fa); 813 814 static inline void ovl_copyflags(struct inode *from, struct inode *to) 815 { 816 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 817 818 inode_set_flags(to, from->i_flags & mask, mask); 819 } 820 821 /* dir.c */ 822 extern const struct inode_operations ovl_dir_inode_operations; 823 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, 824 struct dentry *dentry); 825 struct ovl_cattr { 826 dev_t rdev; 827 umode_t mode; 828 const char *link; 829 struct dentry *hardlink; 830 }; 831 832 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 833 834 int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, 835 struct dentry **newdentry, umode_t mode); 836 struct dentry *ovl_create_real(struct ovl_fs *ofs, 837 struct inode *dir, struct dentry *newdentry, 838 struct ovl_cattr *attr); 839 int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); 840 struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); 841 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, 842 struct ovl_cattr *attr); 843 844 /* file.c */ 845 extern const struct file_operations ovl_file_operations; 846 int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa); 847 int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa); 848 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); 849 int ovl_fileattr_set(struct mnt_idmap *idmap, 850 struct dentry *dentry, struct fileattr *fa); 851 852 /* copy_up.c */ 853 int ovl_copy_up(struct dentry *dentry); 854 int ovl_copy_up_with_data(struct dentry *dentry); 855 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 856 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); 857 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); 858 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, 859 bool is_upper); 860 struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin); 861 int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh, 862 struct dentry *upper); 863 864 /* export.c */ 865 extern const struct export_operations ovl_export_operations; 866 extern const struct export_operations ovl_export_fid_operations; 867 868 /* super.c */ 869 int ovl_fill_super(struct super_block *sb, struct fs_context *fc); 870 871 /* Will this overlay be forced to mount/remount ro? */ 872 static inline bool ovl_force_readonly(struct ovl_fs *ofs) 873 { 874 return (!ovl_upper_mnt(ofs) || !ofs->workdir); 875 } 876 877 /* xattr.c */ 878 879 const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs); 880 int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 881 struct iattr *attr); 882 int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, 883 struct kstat *stat, u32 request_mask, unsigned int flags); 884 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 885