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