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 = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, 333 mode, O_LARGEFILE | O_WRONLY, 334 current_cred()); 335 int err = PTR_ERR_OR_ZERO(file); 336 337 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 338 return file; 339 } 340 341 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, 342 const char *name, 343 struct dentry *base, int len) 344 { 345 return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len); 346 } 347 348 static inline bool ovl_open_flags_need_copy_up(int flags) 349 { 350 if (!flags) 351 return false; 352 353 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 354 } 355 356 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 357 { 358 /* 359 * To avoid regressions in existing setups with overlay lower offline 360 * changes, we allow lower changes only if none of the new features 361 * are used. 362 */ 363 return (!ofs->config.index && !ofs->config.metacopy && 364 !ofs->config.redirect_dir && ofs->config.xino != OVL_XINO_ON); 365 } 366 367 368 /* util.c */ 369 int ovl_want_write(struct dentry *dentry); 370 void ovl_drop_write(struct dentry *dentry); 371 struct dentry *ovl_workdir(struct dentry *dentry); 372 const struct cred *ovl_override_creds(struct super_block *sb); 373 int ovl_can_decode_fh(struct super_block *sb); 374 struct dentry *ovl_indexdir(struct super_block *sb); 375 bool ovl_index_all(struct super_block *sb); 376 bool ovl_verify_lower(struct super_block *sb); 377 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 378 bool ovl_dentry_remote(struct dentry *dentry); 379 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry, 380 unsigned int mask); 381 bool ovl_dentry_weird(struct dentry *dentry); 382 enum ovl_path_type ovl_path_type(struct dentry *dentry); 383 void ovl_path_upper(struct dentry *dentry, struct path *path); 384 void ovl_path_lower(struct dentry *dentry, struct path *path); 385 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 386 void ovl_i_path_real(struct inode *inode, struct path *path); 387 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 388 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); 389 struct dentry *ovl_dentry_upper(struct dentry *dentry); 390 struct dentry *ovl_dentry_lower(struct dentry *dentry); 391 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 392 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); 393 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 394 struct dentry *ovl_dentry_real(struct dentry *dentry); 395 struct dentry *ovl_i_dentry_upper(struct inode *inode); 396 struct inode *ovl_inode_upper(struct inode *inode); 397 struct inode *ovl_inode_lower(struct inode *inode); 398 struct inode *ovl_inode_lowerdata(struct inode *inode); 399 struct inode *ovl_inode_real(struct inode *inode); 400 struct inode *ovl_inode_realdata(struct inode *inode); 401 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 402 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 403 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 404 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 405 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 406 bool ovl_dentry_is_opaque(struct dentry *dentry); 407 bool ovl_dentry_is_whiteout(struct dentry *dentry); 408 void ovl_dentry_set_opaque(struct dentry *dentry); 409 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 410 void ovl_dentry_set_upper_alias(struct dentry *dentry); 411 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 412 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 413 bool ovl_has_upperdata(struct inode *inode); 414 void ovl_set_upperdata(struct inode *inode); 415 bool ovl_redirect_dir(struct super_block *sb); 416 const char *ovl_dentry_get_redirect(struct dentry *dentry); 417 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 418 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 419 void ovl_dir_modified(struct dentry *dentry, bool impurity); 420 u64 ovl_inode_version_get(struct inode *inode); 421 bool ovl_is_whiteout(struct dentry *dentry); 422 struct file *ovl_path_open(const struct path *path, int flags); 423 int ovl_copy_up_start(struct dentry *dentry, int flags); 424 void ovl_copy_up_end(struct dentry *dentry); 425 bool ovl_already_copied_up(struct dentry *dentry, int flags); 426 bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, 427 enum ovl_xattr ox); 428 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); 429 430 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, 431 struct dentry *upperdentry) 432 { 433 struct path upperpath = { 434 .dentry = upperdentry, 435 .mnt = ovl_upper_mnt(ofs), 436 }; 437 return ovl_path_check_origin_xattr(ofs, &upperpath); 438 } 439 440 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 441 enum ovl_xattr ox, const void *value, size_t size, 442 int xerr); 443 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 444 bool ovl_inuse_trylock(struct dentry *dentry); 445 void ovl_inuse_unlock(struct dentry *dentry); 446 bool ovl_is_inuse(struct dentry *dentry); 447 bool ovl_need_index(struct dentry *dentry); 448 int ovl_nlink_start(struct dentry *dentry); 449 void ovl_nlink_end(struct dentry *dentry); 450 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); 451 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path); 452 bool ovl_is_metacopy_dentry(struct dentry *dentry); 453 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); 454 int ovl_sync_status(struct ovl_fs *ofs); 455 456 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 457 { 458 set_bit(flag, &OVL_I(inode)->flags); 459 } 460 461 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 462 { 463 clear_bit(flag, &OVL_I(inode)->flags); 464 } 465 466 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 467 { 468 return test_bit(flag, &OVL_I(inode)->flags); 469 } 470 471 static inline bool ovl_is_impuredir(struct super_block *sb, 472 struct dentry *upperdentry) 473 { 474 struct ovl_fs *ofs = OVL_FS(sb); 475 struct path upperpath = { 476 .dentry = upperdentry, 477 .mnt = ovl_upper_mnt(ofs), 478 }; 479 480 return ovl_path_check_dir_xattr(ofs, &upperpath, OVL_XATTR_IMPURE); 481 } 482 483 /* 484 * With xino=auto, we do best effort to keep all inodes on same st_dev and 485 * d_ino consistent with st_ino. 486 * With xino=on, we do the same effort but we warn if we failed. 487 */ 488 static inline bool ovl_xino_warn(struct super_block *sb) 489 { 490 return OVL_FS(sb)->config.xino == OVL_XINO_ON; 491 } 492 493 /* All layers on same fs? */ 494 static inline bool ovl_same_fs(struct super_block *sb) 495 { 496 return OVL_FS(sb)->xino_mode == 0; 497 } 498 499 /* All overlay inodes have same st_dev? */ 500 static inline bool ovl_same_dev(struct super_block *sb) 501 { 502 return OVL_FS(sb)->xino_mode >= 0; 503 } 504 505 static inline unsigned int ovl_xino_bits(struct super_block *sb) 506 { 507 return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0; 508 } 509 510 static inline void ovl_inode_lock(struct inode *inode) 511 { 512 mutex_lock(&OVL_I(inode)->lock); 513 } 514 515 static inline int ovl_inode_lock_interruptible(struct inode *inode) 516 { 517 return mutex_lock_interruptible(&OVL_I(inode)->lock); 518 } 519 520 static inline void ovl_inode_unlock(struct inode *inode) 521 { 522 mutex_unlock(&OVL_I(inode)->lock); 523 } 524 525 526 /* namei.c */ 527 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 528 529 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 530 { 531 if (fh_len < sizeof(struct ovl_fh)) 532 return -EINVAL; 533 534 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 535 } 536 537 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 538 struct vfsmount *mnt, bool connected); 539 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 540 struct dentry *upperdentry, struct ovl_path **stackp); 541 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 542 enum ovl_xattr ox, struct dentry *real, bool is_upper, 543 bool set); 544 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, 545 bool connected); 546 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 547 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 548 struct qstr *name); 549 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 550 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 551 struct dentry *origin, bool verify); 552 int ovl_path_next(int idx, struct dentry *dentry, struct path *path); 553 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 554 unsigned int flags); 555 bool ovl_lower_positive(struct dentry *dentry); 556 557 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 558 struct dentry *origin, bool set) 559 { 560 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, origin, 561 false, set); 562 } 563 564 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 565 struct dentry *upper, bool set) 566 { 567 return ovl_verify_set_fh(ofs, index, OVL_XATTR_UPPER, upper, true, set); 568 } 569 570 /* readdir.c */ 571 extern const struct file_operations ovl_dir_operations; 572 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 573 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 574 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, 575 struct list_head *list); 576 void ovl_cache_free(struct list_head *list); 577 void ovl_dir_cache_free(struct inode *inode); 578 int ovl_check_d_type_supported(const struct path *realpath); 579 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir, 580 struct vfsmount *mnt, struct dentry *dentry, int level); 581 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 582 583 /* 584 * Can we iterate real dir directly? 585 * 586 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 587 * lower dir was removed under it and possibly before it was rotated from upper 588 * to lower layer. 589 */ 590 static inline bool ovl_dir_is_real(struct inode *dir) 591 { 592 return !ovl_test_flag(OVL_WHITEOUTS, dir); 593 } 594 595 /* inode.c */ 596 int ovl_set_nlink_upper(struct dentry *dentry); 597 int ovl_set_nlink_lower(struct dentry *dentry); 598 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 599 struct dentry *upperdentry, 600 unsigned int fallback); 601 int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 602 struct iattr *attr); 603 int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, 604 struct kstat *stat, u32 request_mask, unsigned int flags); 605 int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, 606 int mask); 607 int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name, 608 const void *value, size_t size, int flags); 609 int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, 610 void *value, size_t size); 611 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 612 613 #ifdef CONFIG_FS_POSIX_ACL 614 struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, 615 struct inode *inode, int type, 616 bool rcu, bool noperm); 617 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, 618 bool rcu) 619 { 620 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true); 621 } 622 static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, 623 struct dentry *dentry, int type) 624 { 625 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false); 626 } 627 int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 628 struct posix_acl *acl, int type); 629 struct posix_acl *ovl_get_acl_path(const struct path *path, 630 const char *acl_name, bool noperm); 631 #else 632 #define ovl_get_inode_acl NULL 633 #define ovl_get_acl NULL 634 #define ovl_set_acl NULL 635 static inline struct posix_acl *ovl_get_acl_path(const struct path *path, 636 const char *acl_name, 637 bool noperm) 638 { 639 return NULL; 640 } 641 #endif 642 643 int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags); 644 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 645 646 struct ovl_inode_params { 647 struct inode *newinode; 648 struct dentry *upperdentry; 649 struct ovl_path *lowerpath; 650 bool index; 651 unsigned int numlower; 652 char *redirect; 653 struct dentry *lowerdata; 654 }; 655 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 656 unsigned long ino, int fsid); 657 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 658 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 659 bool is_upper); 660 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 661 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 662 struct inode *ovl_get_inode(struct super_block *sb, 663 struct ovl_inode_params *oip); 664 void ovl_copyattr(struct inode *to); 665 666 /* vfs inode flags copied from real to ovl inode */ 667 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE) 668 /* vfs inode flags read from overlay.protattr xattr to ovl inode */ 669 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 670 671 /* 672 * fileattr flags copied from lower to upper inode on copy up. 673 * We cannot copy up immutable/append-only flags, because that would prevent 674 * linking temp inode to upper dir, so we store them in xattr instead. 675 */ 676 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 677 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 678 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 679 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 680 681 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 682 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 683 struct fileattr *fa); 684 685 static inline void ovl_copyflags(struct inode *from, struct inode *to) 686 { 687 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 688 689 inode_set_flags(to, from->i_flags & mask, mask); 690 } 691 692 /* dir.c */ 693 extern const struct inode_operations ovl_dir_inode_operations; 694 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, 695 struct dentry *dentry); 696 struct ovl_cattr { 697 dev_t rdev; 698 umode_t mode; 699 const char *link; 700 struct dentry *hardlink; 701 }; 702 703 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 704 705 int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, 706 struct dentry **newdentry, umode_t mode); 707 struct dentry *ovl_create_real(struct ovl_fs *ofs, 708 struct inode *dir, struct dentry *newdentry, 709 struct ovl_cattr *attr); 710 int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); 711 struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); 712 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, 713 struct ovl_cattr *attr); 714 715 /* file.c */ 716 extern const struct file_operations ovl_file_operations; 717 int __init ovl_aio_request_cache_init(void); 718 void ovl_aio_request_cache_destroy(void); 719 int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa); 720 int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa); 721 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); 722 int ovl_fileattr_set(struct mnt_idmap *idmap, 723 struct dentry *dentry, struct fileattr *fa); 724 725 /* copy_up.c */ 726 int ovl_copy_up(struct dentry *dentry); 727 int ovl_copy_up_with_data(struct dentry *dentry); 728 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 729 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); 730 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); 731 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, 732 bool is_upper); 733 int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower, 734 struct dentry *upper); 735 736 /* export.c */ 737 extern const struct export_operations ovl_export_operations; 738