fs/overlayfs/overlayfs.h

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