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/namei.h> 11 #include <linux/posix_acl.h> 12 #include <linux/posix_acl_xattr.h> 13 #include "ovl_entry.h" 14 15 #undef pr_fmt 16 #define pr_fmt(fmt) "overlayfs: " fmt 17 18 enum ovl_path_type { 19 __OVL_PATH_UPPER = (1 << 0), 20 __OVL_PATH_MERGE = (1 << 1), 21 __OVL_PATH_ORIGIN = (1 << 2), 22 }; 23 24 #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER) 25 #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE) 26 #define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN) 27 28 #define OVL_XATTR_NAMESPACE "overlay." 29 #define OVL_XATTR_TRUSTED_PREFIX XATTR_TRUSTED_PREFIX OVL_XATTR_NAMESPACE 30 #define OVL_XATTR_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE 31 32 enum ovl_xattr { 33 OVL_XATTR_OPAQUE, 34 OVL_XATTR_REDIRECT, 35 OVL_XATTR_ORIGIN, 36 OVL_XATTR_IMPURE, 37 OVL_XATTR_NLINK, 38 OVL_XATTR_UPPER, 39 OVL_XATTR_METACOPY, 40 OVL_XATTR_PROTATTR, 41 }; 42 43 enum ovl_inode_flag { 44 /* Pure upper dir that may contain non pure upper entries */ 45 OVL_IMPURE, 46 /* Non-merge dir that may contain whiteout entries */ 47 OVL_WHITEOUTS, 48 OVL_INDEX, 49 OVL_UPPERDATA, 50 /* Inode number will remain constant over copy up. */ 51 OVL_CONST_INO, 52 }; 53 54 enum ovl_entry_flag { 55 OVL_E_UPPER_ALIAS, 56 OVL_E_OPAQUE, 57 OVL_E_CONNECTED, 58 }; 59 60 enum { 61 OVL_REDIRECT_OFF, /* "off" mode is never used. In effect */ 62 OVL_REDIRECT_FOLLOW, /* ...it translates to either "follow" */ 63 OVL_REDIRECT_NOFOLLOW, /* ...or "nofollow". */ 64 OVL_REDIRECT_ON, 65 }; 66 67 enum { 68 OVL_XINO_OFF, 69 OVL_XINO_AUTO, 70 OVL_XINO_ON, 71 }; 72 73 /* 74 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin, 75 * where: 76 * origin.fh - exported file handle of the lower file 77 * origin.uuid - uuid of the lower filesystem 78 */ 79 #define OVL_FH_VERSION 0 80 #define OVL_FH_MAGIC 0xfb 81 82 /* CPU byte order required for fid decoding: */ 83 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0) 84 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1) 85 /* Is the real inode encoded in fid an upper inode? */ 86 #define OVL_FH_FLAG_PATH_UPPER (1 << 2) 87 88 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \ 89 OVL_FH_FLAG_PATH_UPPER) 90 91 #if defined(__LITTLE_ENDIAN) 92 #define OVL_FH_FLAG_CPU_ENDIAN 0 93 #elif defined(__BIG_ENDIAN) 94 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN 95 #else 96 #error Endianness not defined 97 #endif 98 99 /* The type used to be returned by overlay exportfs for misaligned fid */ 100 #define OVL_FILEID_V0 0xfb 101 /* The type returned by overlay exportfs for 32bit aligned fid */ 102 #define OVL_FILEID_V1 0xf8 103 104 /* On-disk format for "origin" file handle */ 105 struct ovl_fb { 106 u8 version; /* 0 */ 107 u8 magic; /* 0xfb */ 108 u8 len; /* size of this header + size of fid */ 109 u8 flags; /* OVL_FH_FLAG_* */ 110 u8 type; /* fid_type of fid */ 111 uuid_t uuid; /* uuid of filesystem */ 112 u32 fid[]; /* file identifier should be 32bit aligned in-memory */ 113 } __packed; 114 115 /* In-memory and on-wire format for overlay file handle */ 116 struct ovl_fh { 117 u8 padding[3]; /* make sure fb.fid is 32bit aligned */ 118 union { 119 struct ovl_fb fb; 120 DECLARE_FLEX_ARRAY(u8, buf); 121 }; 122 } __packed; 123 124 #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb) 125 #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len) 126 #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \ 127 offsetof(struct ovl_fb, fid)) 128 129 extern const char *const ovl_xattr_table[][2]; 130 static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) 131 { 132 return ovl_xattr_table[ox][ofs->config.userxattr]; 133 } 134 135 /* 136 * When changing ownership of an upper object map the intended ownership 137 * according to the upper layer's idmapping. When an upper mount idmaps files 138 * that are stored on-disk as owned by id 1001 to id 1000 this means stat on 139 * this object will report it as being owned by id 1000 when calling stat via 140 * the upper mount. 141 * In order to change ownership of an object so stat reports id 1000 when 142 * called on an idmapped upper mount the value written to disk - i.e., the 143 * value stored in ia_*id - must 1001. The mount mapping helper will thus take 144 * care to map 1000 to 1001. 145 * The mnt idmapping helpers are nops if the upper layer isn't idmapped. 146 */ 147 static inline int ovl_do_notify_change(struct ovl_fs *ofs, 148 struct dentry *upperdentry, 149 struct iattr *attr) 150 { 151 return notify_change(ovl_upper_mnt_idmap(ofs), upperdentry, attr, NULL); 152 } 153 154 static inline int ovl_do_rmdir(struct ovl_fs *ofs, 155 struct inode *dir, struct dentry *dentry) 156 { 157 int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry); 158 159 pr_debug("rmdir(%pd2) = %i\n", dentry, err); 160 return err; 161 } 162 163 static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir, 164 struct dentry *dentry) 165 { 166 int err = vfs_unlink(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL); 167 168 pr_debug("unlink(%pd2) = %i\n", dentry, err); 169 return err; 170 } 171 172 static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry, 173 struct inode *dir, struct dentry *new_dentry) 174 { 175 int err = vfs_link(old_dentry, ovl_upper_mnt_idmap(ofs), dir, 176 new_dentry, NULL); 177 178 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err); 179 return err; 180 } 181 182 static inline int ovl_do_create(struct ovl_fs *ofs, 183 struct inode *dir, struct dentry *dentry, 184 umode_t mode) 185 { 186 int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true); 187 188 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); 189 return err; 190 } 191 192 static inline int ovl_do_mkdir(struct ovl_fs *ofs, 193 struct inode *dir, struct dentry *dentry, 194 umode_t mode) 195 { 196 int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode); 197 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err); 198 return err; 199 } 200 201 static inline int ovl_do_mknod(struct ovl_fs *ofs, 202 struct inode *dir, struct dentry *dentry, 203 umode_t mode, dev_t dev) 204 { 205 int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev); 206 207 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); 208 return err; 209 } 210 211 static inline int ovl_do_symlink(struct ovl_fs *ofs, 212 struct inode *dir, struct dentry *dentry, 213 const char *oldname) 214 { 215 int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname); 216 217 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); 218 return err; 219 } 220 221 static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, 222 void *value, size_t size) 223 { 224 int err, len; 225 226 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb); 227 228 err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry, 229 name, value, size); 230 len = (value && err > 0) ? err : 0; 231 232 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", 233 path->dentry, name, min(len, 48), value, size, err); 234 return err; 235 } 236 237 static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, 238 struct dentry *upperdentry, 239 enum ovl_xattr ox, void *value, 240 size_t size) 241 { 242 struct path upperpath = { 243 .dentry = upperdentry, 244 .mnt = ovl_upper_mnt(ofs), 245 }; 246 247 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size); 248 } 249 250 static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, 251 const struct path *path, 252 enum ovl_xattr ox, void *value, 253 size_t size) 254 { 255 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size); 256 } 257 258 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 259 const char *name, const void *value, 260 size_t size, int flags) 261 { 262 int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name, 263 value, size, flags); 264 265 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n", 266 dentry, name, min((int)size, 48), value, size, flags, err); 267 return err; 268 } 269 270 static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 271 enum ovl_xattr ox, const void *value, 272 size_t size) 273 { 274 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0); 275 } 276 277 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 278 const char *name) 279 { 280 int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name); 281 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); 282 return err; 283 } 284 285 static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 286 enum ovl_xattr ox) 287 { 288 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox)); 289 } 290 291 static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, 292 const char *acl_name, struct posix_acl *acl) 293 { 294 return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl); 295 } 296 297 static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, 298 const char *acl_name) 299 { 300 return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name); 301 } 302 303 static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir, 304 struct dentry *olddentry, struct inode *newdir, 305 struct dentry *newdentry, unsigned int flags) 306 { 307 int err; 308 struct renamedata rd = { 309 .old_mnt_idmap = ovl_upper_mnt_idmap(ofs), 310 .old_dir = olddir, 311 .old_dentry = olddentry, 312 .new_mnt_idmap = ovl_upper_mnt_idmap(ofs), 313 .new_dir = newdir, 314 .new_dentry = newdentry, 315 .flags = flags, 316 }; 317 318 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags); 319 err = vfs_rename(&rd); 320 if (err) { 321 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 322 olddentry, newdentry, err); 323 } 324 return err; 325 } 326 327 static inline int ovl_do_whiteout(struct ovl_fs *ofs, 328 struct inode *dir, struct dentry *dentry) 329 { 330 int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry); 331 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 332 return err; 333 } 334 335 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, 336 struct dentry *dentry, umode_t mode) 337 { 338 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry }; 339 struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, 340 mode, O_LARGEFILE | O_WRONLY, 341 current_cred()); 342 int err = PTR_ERR_OR_ZERO(file); 343 344 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 345 return file; 346 } 347 348 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, 349 const char *name, 350 struct dentry *base, int len) 351 { 352 return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len); 353 } 354 355 static inline bool ovl_open_flags_need_copy_up(int flags) 356 { 357 if (!flags) 358 return false; 359 360 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 361 } 362 363 /* util.c */ 364 int ovl_want_write(struct dentry *dentry); 365 void ovl_drop_write(struct dentry *dentry); 366 struct dentry *ovl_workdir(struct dentry *dentry); 367 const struct cred *ovl_override_creds(struct super_block *sb); 368 int ovl_can_decode_fh(struct super_block *sb); 369 struct dentry *ovl_indexdir(struct super_block *sb); 370 bool ovl_index_all(struct super_block *sb); 371 bool ovl_verify_lower(struct super_block *sb); 372 struct ovl_path *ovl_stack_alloc(unsigned int n); 373 void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); 374 void ovl_stack_put(struct ovl_path *stack, unsigned int n); 375 void ovl_stack_free(struct ovl_path *stack, unsigned int n); 376 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 377 void ovl_free_entry(struct ovl_entry *oe); 378 bool ovl_dentry_remote(struct dentry *dentry); 379 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); 380 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, 381 struct ovl_entry *oe); 382 void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, 383 struct ovl_entry *oe, unsigned int mask); 384 bool ovl_dentry_weird(struct dentry *dentry); 385 enum ovl_path_type ovl_path_type(struct dentry *dentry); 386 void ovl_path_upper(struct dentry *dentry, struct path *path); 387 void ovl_path_lower(struct dentry *dentry, struct path *path); 388 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 389 struct inode *ovl_i_path_real(struct inode *inode, struct path *path); 390 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 391 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); 392 struct dentry *ovl_dentry_upper(struct dentry *dentry); 393 struct dentry *ovl_dentry_lower(struct dentry *dentry); 394 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 395 int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); 396 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); 397 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 398 struct dentry *ovl_dentry_real(struct dentry *dentry); 399 struct dentry *ovl_i_dentry_upper(struct inode *inode); 400 struct inode *ovl_inode_upper(struct inode *inode); 401 struct inode *ovl_inode_lower(struct inode *inode); 402 struct inode *ovl_inode_lowerdata(struct inode *inode); 403 struct inode *ovl_inode_real(struct inode *inode); 404 struct inode *ovl_inode_realdata(struct inode *inode); 405 const char *ovl_lowerdata_redirect(struct inode *inode); 406 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 407 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 408 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 409 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 410 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 411 bool ovl_dentry_is_opaque(struct dentry *dentry); 412 bool ovl_dentry_is_whiteout(struct dentry *dentry); 413 void ovl_dentry_set_opaque(struct dentry *dentry); 414 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 415 void ovl_dentry_set_upper_alias(struct dentry *dentry); 416 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 417 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 418 bool ovl_has_upperdata(struct inode *inode); 419 void ovl_set_upperdata(struct inode *inode); 420 const char *ovl_dentry_get_redirect(struct dentry *dentry); 421 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 422 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 423 void ovl_dir_modified(struct dentry *dentry, bool impurity); 424 u64 ovl_inode_version_get(struct inode *inode); 425 bool ovl_is_whiteout(struct dentry *dentry); 426 struct file *ovl_path_open(const struct path *path, int flags); 427 int ovl_copy_up_start(struct dentry *dentry, int flags); 428 void ovl_copy_up_end(struct dentry *dentry); 429 bool ovl_already_copied_up(struct dentry *dentry, int flags); 430 bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, 431 enum ovl_xattr ox); 432 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); 433 434 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, 435 struct dentry *upperdentry) 436 { 437 struct path upperpath = { 438 .dentry = upperdentry, 439 .mnt = ovl_upper_mnt(ofs), 440 }; 441 return ovl_path_check_origin_xattr(ofs, &upperpath); 442 } 443 444 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 445 enum ovl_xattr ox, const void *value, size_t size, 446 int xerr); 447 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 448 bool ovl_inuse_trylock(struct dentry *dentry); 449 void ovl_inuse_unlock(struct dentry *dentry); 450 bool ovl_is_inuse(struct dentry *dentry); 451 bool ovl_need_index(struct dentry *dentry); 452 int ovl_nlink_start(struct dentry *dentry); 453 void ovl_nlink_end(struct dentry *dentry); 454 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); 455 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path); 456 bool ovl_is_metacopy_dentry(struct dentry *dentry); 457 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); 458 int ovl_sync_status(struct ovl_fs *ofs); 459 460 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 461 { 462 set_bit(flag, &OVL_I(inode)->flags); 463 } 464 465 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 466 { 467 clear_bit(flag, &OVL_I(inode)->flags); 468 } 469 470 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 471 { 472 return test_bit(flag, &OVL_I(inode)->flags); 473 } 474 475 static inline bool ovl_is_impuredir(struct super_block *sb, 476 struct dentry *upperdentry) 477 { 478 struct ovl_fs *ofs = OVL_FS(sb); 479 struct path upperpath = { 480 .dentry = upperdentry, 481 .mnt = ovl_upper_mnt(ofs), 482 }; 483 484 return ovl_path_check_dir_xattr(ofs, &upperpath, OVL_XATTR_IMPURE); 485 } 486 487 static inline bool ovl_redirect_follow(struct ovl_fs *ofs) 488 { 489 return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW; 490 } 491 492 static inline bool ovl_redirect_dir(struct ovl_fs *ofs) 493 { 494 return ofs->config.redirect_mode == OVL_REDIRECT_ON; 495 } 496 497 /* 498 * With xino=auto, we do best effort to keep all inodes on same st_dev and 499 * d_ino consistent with st_ino. 500 * With xino=on, we do the same effort but we warn if we failed. 501 */ 502 static inline bool ovl_xino_warn(struct ovl_fs *ofs) 503 { 504 return ofs->config.xino == OVL_XINO_ON; 505 } 506 507 /* 508 * To avoid regressions in existing setups with overlay lower offline changes, 509 * we allow lower changes only if none of the new features are used. 510 */ 511 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 512 { 513 return (!ofs->config.index && !ofs->config.metacopy && 514 !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs)); 515 } 516 517 /* All layers on same fs? */ 518 static inline bool ovl_same_fs(struct ovl_fs *ofs) 519 { 520 return ofs->xino_mode == 0; 521 } 522 523 /* All overlay inodes have same st_dev? */ 524 static inline bool ovl_same_dev(struct ovl_fs *ofs) 525 { 526 return ofs->xino_mode >= 0; 527 } 528 529 static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) 530 { 531 return ovl_same_dev(ofs) ? ofs->xino_mode : 0; 532 } 533 534 static inline void ovl_inode_lock(struct inode *inode) 535 { 536 mutex_lock(&OVL_I(inode)->lock); 537 } 538 539 static inline int ovl_inode_lock_interruptible(struct inode *inode) 540 { 541 return mutex_lock_interruptible(&OVL_I(inode)->lock); 542 } 543 544 static inline void ovl_inode_unlock(struct inode *inode) 545 { 546 mutex_unlock(&OVL_I(inode)->lock); 547 } 548 549 550 /* namei.c */ 551 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 552 553 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 554 { 555 if (fh_len < sizeof(struct ovl_fh)) 556 return -EINVAL; 557 558 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 559 } 560 561 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 562 struct vfsmount *mnt, bool connected); 563 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 564 struct dentry *upperdentry, struct ovl_path **stackp); 565 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 566 enum ovl_xattr ox, struct dentry *real, bool is_upper, 567 bool set); 568 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, 569 bool connected); 570 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 571 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 572 struct qstr *name); 573 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 574 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 575 struct dentry *origin, bool verify); 576 int ovl_path_next(int idx, struct dentry *dentry, struct path *path); 577 int ovl_maybe_lookup_lowerdata(struct dentry *dentry); 578 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 579 unsigned int flags); 580 bool ovl_lower_positive(struct dentry *dentry); 581 582 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 583 struct dentry *origin, bool set) 584 { 585 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, origin, 586 false, set); 587 } 588 589 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 590 struct dentry *upper, bool set) 591 { 592 return ovl_verify_set_fh(ofs, index, OVL_XATTR_UPPER, upper, true, set); 593 } 594 595 /* readdir.c */ 596 extern const struct file_operations ovl_dir_operations; 597 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 598 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 599 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 600 struct list_head *list); 601 void ovl_cache_free(struct list_head *list); 602 void ovl_dir_cache_free(struct inode *inode); 603 int ovl_check_d_type_supported(const struct path *realpath); 604 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir, 605 struct vfsmount *mnt, struct dentry *dentry, int level); 606 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 607 608 /* 609 * Can we iterate real dir directly? 610 * 611 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 612 * lower dir was removed under it and possibly before it was rotated from upper 613 * to lower layer. 614 */ 615 static inline bool ovl_dir_is_real(struct inode *dir) 616 { 617 return !ovl_test_flag(OVL_WHITEOUTS, dir); 618 } 619 620 /* inode.c */ 621 int ovl_set_nlink_upper(struct dentry *dentry); 622 int ovl_set_nlink_lower(struct dentry *dentry); 623 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 624 struct dentry *upperdentry, 625 unsigned int fallback); 626 int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 627 struct iattr *attr); 628 int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, 629 struct kstat *stat, u32 request_mask, unsigned int flags); 630 int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, 631 int mask); 632 int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name, 633 const void *value, size_t size, int flags); 634 int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, 635 void *value, size_t size); 636 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 637 638 #ifdef CONFIG_FS_POSIX_ACL 639 struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, 640 struct inode *inode, int type, 641 bool rcu, bool noperm); 642 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, 643 bool rcu) 644 { 645 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true); 646 } 647 static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, 648 struct dentry *dentry, int type) 649 { 650 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false); 651 } 652 int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 653 struct posix_acl *acl, int type); 654 struct posix_acl *ovl_get_acl_path(const struct path *path, 655 const char *acl_name, bool noperm); 656 #else 657 #define ovl_get_inode_acl NULL 658 #define ovl_get_acl NULL 659 #define ovl_set_acl NULL 660 static inline struct posix_acl *ovl_get_acl_path(const struct path *path, 661 const char *acl_name, 662 bool noperm) 663 { 664 return NULL; 665 } 666 #endif 667 668 int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags); 669 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 670 671 struct ovl_inode_params { 672 struct inode *newinode; 673 struct dentry *upperdentry; 674 struct ovl_entry *oe; 675 bool index; 676 char *redirect; 677 char *lowerdata_redirect; 678 }; 679 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 680 unsigned long ino, int fsid); 681 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 682 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 683 bool is_upper); 684 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 685 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 686 struct inode *ovl_get_inode(struct super_block *sb, 687 struct ovl_inode_params *oip); 688 void ovl_copyattr(struct inode *to); 689 690 /* vfs inode flags copied from real to ovl inode */ 691 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE) 692 /* vfs inode flags read from overlay.protattr xattr to ovl inode */ 693 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 694 695 /* 696 * fileattr flags copied from lower to upper inode on copy up. 697 * We cannot copy up immutable/append-only flags, because that would prevent 698 * linking temp inode to upper dir, so we store them in xattr instead. 699 */ 700 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 701 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 702 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 703 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 704 705 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 706 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 707 struct fileattr *fa); 708 709 static inline void ovl_copyflags(struct inode *from, struct inode *to) 710 { 711 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 712 713 inode_set_flags(to, from->i_flags & mask, mask); 714 } 715 716 /* dir.c */ 717 extern const struct inode_operations ovl_dir_inode_operations; 718 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, 719 struct dentry *dentry); 720 struct ovl_cattr { 721 dev_t rdev; 722 umode_t mode; 723 const char *link; 724 struct dentry *hardlink; 725 }; 726 727 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 728 729 int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, 730 struct dentry **newdentry, umode_t mode); 731 struct dentry *ovl_create_real(struct ovl_fs *ofs, 732 struct inode *dir, struct dentry *newdentry, 733 struct ovl_cattr *attr); 734 int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); 735 struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); 736 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, 737 struct ovl_cattr *attr); 738 739 /* file.c */ 740 extern const struct file_operations ovl_file_operations; 741 int __init ovl_aio_request_cache_init(void); 742 void ovl_aio_request_cache_destroy(void); 743 int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa); 744 int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa); 745 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); 746 int ovl_fileattr_set(struct mnt_idmap *idmap, 747 struct dentry *dentry, struct fileattr *fa); 748 749 /* copy_up.c */ 750 int ovl_copy_up(struct dentry *dentry); 751 int ovl_copy_up_with_data(struct dentry *dentry); 752 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 753 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); 754 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); 755 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, 756 bool is_upper); 757 int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower, 758 struct dentry *upper); 759 760 /* export.c */ 761 extern const struct export_operations ovl_export_operations; 762 763 /* super.c */ 764 int ovl_fill_super(struct super_block *sb, struct fs_context *fc); 765 766 /* Will this overlay be forced to mount/remount ro? */ 767 static inline bool ovl_force_readonly(struct ovl_fs *ofs) 768 { 769 return (!ovl_upper_mnt(ofs) || !ofs->workdir); 770 } 771