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 "ovl_entry.h" 11 12 #undef pr_fmt 13 #define pr_fmt(fmt) "overlayfs: " fmt 14 15 enum ovl_path_type { 16 __OVL_PATH_UPPER = (1 << 0), 17 __OVL_PATH_MERGE = (1 << 1), 18 __OVL_PATH_ORIGIN = (1 << 2), 19 }; 20 21 #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER) 22 #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE) 23 #define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN) 24 25 #define OVL_XATTR_NAMESPACE "overlay." 26 #define OVL_XATTR_TRUSTED_PREFIX XATTR_TRUSTED_PREFIX OVL_XATTR_NAMESPACE 27 #define OVL_XATTR_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE 28 29 enum ovl_xattr { 30 OVL_XATTR_OPAQUE, 31 OVL_XATTR_REDIRECT, 32 OVL_XATTR_ORIGIN, 33 OVL_XATTR_IMPURE, 34 OVL_XATTR_NLINK, 35 OVL_XATTR_UPPER, 36 OVL_XATTR_METACOPY, 37 OVL_XATTR_PROTATTR, 38 }; 39 40 enum ovl_inode_flag { 41 /* Pure upper dir that may contain non pure upper entries */ 42 OVL_IMPURE, 43 /* Non-merge dir that may contain whiteout entries */ 44 OVL_WHITEOUTS, 45 OVL_INDEX, 46 OVL_UPPERDATA, 47 /* Inode number will remain constant over copy up. */ 48 OVL_CONST_INO, 49 }; 50 51 enum ovl_entry_flag { 52 OVL_E_UPPER_ALIAS, 53 OVL_E_OPAQUE, 54 OVL_E_CONNECTED, 55 }; 56 57 enum { 58 OVL_XINO_OFF, 59 OVL_XINO_AUTO, 60 OVL_XINO_ON, 61 }; 62 63 /* 64 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin, 65 * where: 66 * origin.fh - exported file handle of the lower file 67 * origin.uuid - uuid of the lower filesystem 68 */ 69 #define OVL_FH_VERSION 0 70 #define OVL_FH_MAGIC 0xfb 71 72 /* CPU byte order required for fid decoding: */ 73 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0) 74 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1) 75 /* Is the real inode encoded in fid an upper inode? */ 76 #define OVL_FH_FLAG_PATH_UPPER (1 << 2) 77 78 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \ 79 OVL_FH_FLAG_PATH_UPPER) 80 81 #if defined(__LITTLE_ENDIAN) 82 #define OVL_FH_FLAG_CPU_ENDIAN 0 83 #elif defined(__BIG_ENDIAN) 84 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN 85 #else 86 #error Endianness not defined 87 #endif 88 89 /* The type used to be returned by overlay exportfs for misaligned fid */ 90 #define OVL_FILEID_V0 0xfb 91 /* The type returned by overlay exportfs for 32bit aligned fid */ 92 #define OVL_FILEID_V1 0xf8 93 94 /* On-disk format for "origin" file handle */ 95 struct ovl_fb { 96 u8 version; /* 0 */ 97 u8 magic; /* 0xfb */ 98 u8 len; /* size of this header + size of fid */ 99 u8 flags; /* OVL_FH_FLAG_* */ 100 u8 type; /* fid_type of fid */ 101 uuid_t uuid; /* uuid of filesystem */ 102 u32 fid[]; /* file identifier should be 32bit aligned in-memory */ 103 } __packed; 104 105 /* In-memory and on-wire format for overlay file handle */ 106 struct ovl_fh { 107 u8 padding[3]; /* make sure fb.fid is 32bit aligned */ 108 union { 109 struct ovl_fb fb; 110 u8 buf[0]; 111 }; 112 } __packed; 113 114 #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb) 115 #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len) 116 #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \ 117 offsetof(struct ovl_fb, fid)) 118 119 extern const char *const ovl_xattr_table[][2]; 120 static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) 121 { 122 return ovl_xattr_table[ox][ofs->config.userxattr]; 123 } 124 125 static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry) 126 { 127 int err = vfs_rmdir(&init_user_ns, dir, dentry); 128 129 pr_debug("rmdir(%pd2) = %i\n", dentry, err); 130 return err; 131 } 132 133 static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry) 134 { 135 int err = vfs_unlink(&init_user_ns, dir, dentry, NULL); 136 137 pr_debug("unlink(%pd2) = %i\n", dentry, err); 138 return err; 139 } 140 141 static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir, 142 struct dentry *new_dentry) 143 { 144 int err = vfs_link(old_dentry, &init_user_ns, dir, new_dentry, NULL); 145 146 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err); 147 return err; 148 } 149 150 static inline int ovl_do_create(struct inode *dir, struct dentry *dentry, 151 umode_t mode) 152 { 153 int err = vfs_create(&init_user_ns, dir, dentry, mode, true); 154 155 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err); 156 return err; 157 } 158 159 static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry, 160 umode_t mode) 161 { 162 int err = vfs_mkdir(&init_user_ns, dir, dentry, mode); 163 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err); 164 return err; 165 } 166 167 static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry, 168 umode_t mode, dev_t dev) 169 { 170 int err = vfs_mknod(&init_user_ns, dir, dentry, mode, dev); 171 172 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err); 173 return err; 174 } 175 176 static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry, 177 const char *oldname) 178 { 179 int err = vfs_symlink(&init_user_ns, dir, dentry, oldname); 180 181 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err); 182 return err; 183 } 184 185 static inline ssize_t ovl_do_getxattr(struct ovl_fs *ofs, struct dentry *dentry, 186 enum ovl_xattr ox, void *value, 187 size_t size) 188 { 189 const char *name = ovl_xattr(ofs, ox); 190 int err = vfs_getxattr(&init_user_ns, dentry, name, value, size); 191 int len = (value && err > 0) ? err : 0; 192 193 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", 194 dentry, name, min(len, 48), value, size, err); 195 return err; 196 } 197 198 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, 199 enum ovl_xattr ox, const void *value, 200 size_t size) 201 { 202 const char *name = ovl_xattr(ofs, ox); 203 int err = vfs_setxattr(&init_user_ns, dentry, name, value, size, 0); 204 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n", 205 dentry, name, min((int)size, 48), value, size, err); 206 return err; 207 } 208 209 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, 210 enum ovl_xattr ox) 211 { 212 const char *name = ovl_xattr(ofs, ox); 213 int err = vfs_removexattr(&init_user_ns, dentry, name); 214 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err); 215 return err; 216 } 217 218 static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry, 219 struct inode *newdir, struct dentry *newdentry, 220 unsigned int flags) 221 { 222 int err; 223 struct renamedata rd = { 224 .old_mnt_userns = &init_user_ns, 225 .old_dir = olddir, 226 .old_dentry = olddentry, 227 .new_mnt_userns = &init_user_ns, 228 .new_dir = newdir, 229 .new_dentry = newdentry, 230 .flags = flags, 231 }; 232 233 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags); 234 err = vfs_rename(&rd); 235 if (err) { 236 pr_debug("...rename(%pd2, %pd2, ...) = %i\n", 237 olddentry, newdentry, err); 238 } 239 return err; 240 } 241 242 static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry) 243 { 244 int err = vfs_whiteout(&init_user_ns, dir, dentry); 245 pr_debug("whiteout(%pd2) = %i\n", dentry, err); 246 return err; 247 } 248 249 static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode) 250 { 251 struct dentry *ret = vfs_tmpfile(&init_user_ns, dentry, mode, 0); 252 int err = PTR_ERR_OR_ZERO(ret); 253 254 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err); 255 return ret; 256 } 257 258 static inline bool ovl_open_flags_need_copy_up(int flags) 259 { 260 if (!flags) 261 return false; 262 263 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)); 264 } 265 266 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) 267 { 268 /* 269 * To avoid regressions in existing setups with overlay lower offline 270 * changes, we allow lower changes only if none of the new features 271 * are used. 272 */ 273 return (!ofs->config.index && !ofs->config.metacopy && 274 !ofs->config.redirect_dir && ofs->config.xino != OVL_XINO_ON); 275 } 276 277 278 /* util.c */ 279 int ovl_want_write(struct dentry *dentry); 280 void ovl_drop_write(struct dentry *dentry); 281 struct dentry *ovl_workdir(struct dentry *dentry); 282 const struct cred *ovl_override_creds(struct super_block *sb); 283 int ovl_can_decode_fh(struct super_block *sb); 284 struct dentry *ovl_indexdir(struct super_block *sb); 285 bool ovl_index_all(struct super_block *sb); 286 bool ovl_verify_lower(struct super_block *sb); 287 struct ovl_entry *ovl_alloc_entry(unsigned int numlower); 288 bool ovl_dentry_remote(struct dentry *dentry); 289 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry, 290 unsigned int mask); 291 bool ovl_dentry_weird(struct dentry *dentry); 292 enum ovl_path_type ovl_path_type(struct dentry *dentry); 293 void ovl_path_upper(struct dentry *dentry, struct path *path); 294 void ovl_path_lower(struct dentry *dentry, struct path *path); 295 void ovl_path_lowerdata(struct dentry *dentry, struct path *path); 296 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); 297 struct dentry *ovl_dentry_upper(struct dentry *dentry); 298 struct dentry *ovl_dentry_lower(struct dentry *dentry); 299 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); 300 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); 301 struct dentry *ovl_dentry_real(struct dentry *dentry); 302 struct dentry *ovl_i_dentry_upper(struct inode *inode); 303 struct inode *ovl_inode_upper(struct inode *inode); 304 struct inode *ovl_inode_lower(struct inode *inode); 305 struct inode *ovl_inode_lowerdata(struct inode *inode); 306 struct inode *ovl_inode_real(struct inode *inode); 307 struct inode *ovl_inode_realdata(struct inode *inode); 308 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); 309 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); 310 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); 311 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); 312 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); 313 bool ovl_dentry_is_opaque(struct dentry *dentry); 314 bool ovl_dentry_is_whiteout(struct dentry *dentry); 315 void ovl_dentry_set_opaque(struct dentry *dentry); 316 bool ovl_dentry_has_upper_alias(struct dentry *dentry); 317 void ovl_dentry_set_upper_alias(struct dentry *dentry); 318 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); 319 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); 320 bool ovl_has_upperdata(struct inode *inode); 321 void ovl_set_upperdata(struct inode *inode); 322 bool ovl_redirect_dir(struct super_block *sb); 323 const char *ovl_dentry_get_redirect(struct dentry *dentry); 324 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); 325 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); 326 void ovl_dir_modified(struct dentry *dentry, bool impurity); 327 u64 ovl_dentry_version_get(struct dentry *dentry); 328 bool ovl_is_whiteout(struct dentry *dentry); 329 struct file *ovl_path_open(struct path *path, int flags); 330 int ovl_copy_up_start(struct dentry *dentry, int flags); 331 void ovl_copy_up_end(struct dentry *dentry); 332 bool ovl_already_copied_up(struct dentry *dentry, int flags); 333 bool ovl_check_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry); 334 bool ovl_check_dir_xattr(struct super_block *sb, struct dentry *dentry, 335 enum ovl_xattr ox); 336 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, 337 enum ovl_xattr ox, const void *value, size_t size, 338 int xerr); 339 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); 340 bool ovl_inuse_trylock(struct dentry *dentry); 341 void ovl_inuse_unlock(struct dentry *dentry); 342 bool ovl_is_inuse(struct dentry *dentry); 343 bool ovl_need_index(struct dentry *dentry); 344 int ovl_nlink_start(struct dentry *dentry); 345 void ovl_nlink_end(struct dentry *dentry); 346 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); 347 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, struct dentry *dentry); 348 bool ovl_is_metacopy_dentry(struct dentry *dentry); 349 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, struct dentry *dentry, 350 int padding); 351 int ovl_sync_status(struct ovl_fs *ofs); 352 353 static inline void ovl_set_flag(unsigned long flag, struct inode *inode) 354 { 355 set_bit(flag, &OVL_I(inode)->flags); 356 } 357 358 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) 359 { 360 clear_bit(flag, &OVL_I(inode)->flags); 361 } 362 363 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) 364 { 365 return test_bit(flag, &OVL_I(inode)->flags); 366 } 367 368 static inline bool ovl_is_impuredir(struct super_block *sb, 369 struct dentry *dentry) 370 { 371 return ovl_check_dir_xattr(sb, dentry, OVL_XATTR_IMPURE); 372 } 373 374 /* 375 * With xino=auto, we do best effort to keep all inodes on same st_dev and 376 * d_ino consistent with st_ino. 377 * With xino=on, we do the same effort but we warn if we failed. 378 */ 379 static inline bool ovl_xino_warn(struct super_block *sb) 380 { 381 return OVL_FS(sb)->config.xino == OVL_XINO_ON; 382 } 383 384 /* All layers on same fs? */ 385 static inline bool ovl_same_fs(struct super_block *sb) 386 { 387 return OVL_FS(sb)->xino_mode == 0; 388 } 389 390 /* All overlay inodes have same st_dev? */ 391 static inline bool ovl_same_dev(struct super_block *sb) 392 { 393 return OVL_FS(sb)->xino_mode >= 0; 394 } 395 396 static inline unsigned int ovl_xino_bits(struct super_block *sb) 397 { 398 return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0; 399 } 400 401 static inline void ovl_inode_lock(struct inode *inode) 402 { 403 mutex_lock(&OVL_I(inode)->lock); 404 } 405 406 static inline int ovl_inode_lock_interruptible(struct inode *inode) 407 { 408 return mutex_lock_interruptible(&OVL_I(inode)->lock); 409 } 410 411 static inline void ovl_inode_unlock(struct inode *inode) 412 { 413 mutex_unlock(&OVL_I(inode)->lock); 414 } 415 416 417 /* namei.c */ 418 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); 419 420 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) 421 { 422 if (fh_len < sizeof(struct ovl_fh)) 423 return -EINVAL; 424 425 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET); 426 } 427 428 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, 429 struct vfsmount *mnt, bool connected); 430 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, 431 struct dentry *upperdentry, struct ovl_path **stackp); 432 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, 433 enum ovl_xattr ox, struct dentry *real, bool is_upper, 434 bool set); 435 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index); 436 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); 437 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, 438 struct qstr *name); 439 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); 440 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, 441 struct dentry *origin, bool verify); 442 int ovl_path_next(int idx, struct dentry *dentry, struct path *path); 443 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, 444 unsigned int flags); 445 bool ovl_lower_positive(struct dentry *dentry); 446 447 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, 448 struct dentry *origin, bool set) 449 { 450 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, origin, 451 false, set); 452 } 453 454 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, 455 struct dentry *upper, bool set) 456 { 457 return ovl_verify_set_fh(ofs, index, OVL_XATTR_UPPER, upper, true, set); 458 } 459 460 /* readdir.c */ 461 extern const struct file_operations ovl_dir_operations; 462 struct file *ovl_dir_real_file(const struct file *file, bool want_upper); 463 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); 464 void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list); 465 void ovl_cache_free(struct list_head *list); 466 void ovl_dir_cache_free(struct inode *inode); 467 int ovl_check_d_type_supported(struct path *realpath); 468 int ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, 469 struct dentry *dentry, int level); 470 int ovl_indexdir_cleanup(struct ovl_fs *ofs); 471 472 /* 473 * Can we iterate real dir directly? 474 * 475 * Non-merge dir may contain whiteouts from a time it was a merge upper, before 476 * lower dir was removed under it and possibly before it was rotated from upper 477 * to lower layer. 478 */ 479 static inline bool ovl_dir_is_real(struct dentry *dir) 480 { 481 return !ovl_test_flag(OVL_WHITEOUTS, d_inode(dir)); 482 } 483 484 /* inode.c */ 485 int ovl_set_nlink_upper(struct dentry *dentry); 486 int ovl_set_nlink_lower(struct dentry *dentry); 487 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, 488 struct dentry *upperdentry, 489 unsigned int fallback); 490 int ovl_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, 491 struct iattr *attr); 492 int ovl_getattr(struct user_namespace *mnt_userns, const struct path *path, 493 struct kstat *stat, u32 request_mask, unsigned int flags); 494 int ovl_permission(struct user_namespace *mnt_userns, struct inode *inode, 495 int mask); 496 int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name, 497 const void *value, size_t size, int flags); 498 int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, 499 void *value, size_t size); 500 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); 501 struct posix_acl *ovl_get_acl(struct inode *inode, int type, bool rcu); 502 int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags); 503 bool ovl_is_private_xattr(struct super_block *sb, const char *name); 504 505 struct ovl_inode_params { 506 struct inode *newinode; 507 struct dentry *upperdentry; 508 struct ovl_path *lowerpath; 509 bool index; 510 unsigned int numlower; 511 char *redirect; 512 struct dentry *lowerdata; 513 }; 514 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, 515 unsigned long ino, int fsid); 516 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); 517 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, 518 bool is_upper); 519 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); 520 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); 521 struct inode *ovl_get_inode(struct super_block *sb, 522 struct ovl_inode_params *oip); 523 static inline void ovl_copyattr(struct inode *from, struct inode *to) 524 { 525 to->i_uid = from->i_uid; 526 to->i_gid = from->i_gid; 527 to->i_mode = from->i_mode; 528 to->i_atime = from->i_atime; 529 to->i_mtime = from->i_mtime; 530 to->i_ctime = from->i_ctime; 531 i_size_write(to, i_size_read(from)); 532 } 533 534 /* vfs inode flags copied from real to ovl inode */ 535 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE) 536 /* vfs inode flags read from overlay.protattr xattr to ovl inode */ 537 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE) 538 539 /* 540 * fileattr flags copied from lower to upper inode on copy up. 541 * We cannot copy up immutable/append-only flags, because that would prevent 542 * linking temp inode to upper dir, so we store them in xattr instead. 543 */ 544 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL) 545 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME) 546 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL) 547 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE) 548 549 void ovl_check_protattr(struct inode *inode, struct dentry *upper); 550 int ovl_set_protattr(struct inode *inode, struct dentry *upper, 551 struct fileattr *fa); 552 553 static inline void ovl_copyflags(struct inode *from, struct inode *to) 554 { 555 unsigned int mask = OVL_COPY_I_FLAGS_MASK; 556 557 inode_set_flags(to, from->i_flags & mask, mask); 558 } 559 560 /* dir.c */ 561 extern const struct inode_operations ovl_dir_inode_operations; 562 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, 563 struct dentry *dentry); 564 struct ovl_cattr { 565 dev_t rdev; 566 umode_t mode; 567 const char *link; 568 struct dentry *hardlink; 569 }; 570 571 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) 572 573 int ovl_mkdir_real(struct inode *dir, struct dentry **newdentry, umode_t mode); 574 struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry, 575 struct ovl_cattr *attr); 576 int ovl_cleanup(struct inode *dir, struct dentry *dentry); 577 struct dentry *ovl_lookup_temp(struct dentry *workdir); 578 struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr); 579 580 /* file.c */ 581 extern const struct file_operations ovl_file_operations; 582 int __init ovl_aio_request_cache_init(void); 583 void ovl_aio_request_cache_destroy(void); 584 int ovl_real_fileattr_get(struct path *realpath, struct fileattr *fa); 585 int ovl_real_fileattr_set(struct path *realpath, struct fileattr *fa); 586 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); 587 int ovl_fileattr_set(struct user_namespace *mnt_userns, 588 struct dentry *dentry, struct fileattr *fa); 589 590 /* copy_up.c */ 591 int ovl_copy_up(struct dentry *dentry); 592 int ovl_copy_up_with_data(struct dentry *dentry); 593 int ovl_maybe_copy_up(struct dentry *dentry, int flags); 594 int ovl_copy_xattr(struct super_block *sb, struct dentry *old, 595 struct dentry *new); 596 int ovl_set_attr(struct dentry *upper, struct kstat *stat); 597 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, 598 bool is_upper); 599 int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower, 600 struct dentry *upper); 601 602 /* export.c */ 603 extern const struct export_operations ovl_export_operations; 604