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