fs/aufs/inode.h

   1 /*
   2  * Copyright (C) 2005-2016 Junjiro R. Okajima
   3  *
   4  * This program, aufs is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * inode operations
  20  */
  21
  22 #ifndef __AUFS_INODE_H__
  23 #define __AUFS_INODE_H__
  24
  25 #ifdef __KERNEL__
  26
  27 #include <linux/fsnotify.h>
  28 #include "rwsem.h"
  29
  30 struct vfsmount;
  31
  32 struct au_hnotify {
  33 #ifdef CONFIG_AUFS_HNOTIFY
  34 #ifdef CONFIG_AUFS_HFSNOTIFY
  35         /* never use fsnotify_add_vfsmount_mark() */
  36         struct fsnotify_mark            hn_mark;
  37 #endif
  38         union {
  39                 struct inode            *hn_aufs_inode; /* no get/put */
  40                 struct llist_node       hn_lnode;       /* delayed free */
  41         };
  42 #endif
  43 } ____cacheline_aligned_in_smp;
  44
  45 struct au_hinode {
  46         struct inode            *hi_inode;
  47         aufs_bindex_t           hi_id;
  48 #ifdef CONFIG_AUFS_HNOTIFY
  49         struct au_hnotify       *hi_notify;
  50 #endif
  51
  52         /* reference to the copied-up whiteout with get/put */
  53         struct dentry           *hi_whdentry;
  54 };
  55
  56 /* ig_flags */
  57 #define AuIG_HALF_REFRESHED             1
  58 #define au_ig_ftest(flags, name)        ((flags) & AuIG_##name)
  59 #define au_ig_fset(flags, name) \
  60         do { (flags) |= AuIG_##name; } while (0)
  61 #define au_ig_fclr(flags, name) \
  62         do { (flags) &= ~AuIG_##name; } while (0)
  63
  64 struct au_iigen {
  65         spinlock_t      ig_spin;
  66         __u32           ig_generation, ig_flags;
  67 };
  68
  69 struct au_vdir;
  70 struct au_iinfo {
  71         struct au_iigen         ii_generation;
  72         struct super_block      *ii_hsb1;       /* no get/put */
  73
  74         struct au_rwsem         ii_rwsem;
  75         aufs_bindex_t           ii_btop, ii_bbot;
  76         __u32                   ii_higen;
  77         struct au_hinode        *ii_hinode;
  78         struct au_vdir          *ii_vdir;
  79 };
  80
  81 struct au_icntnr {
  82         struct au_iinfo iinfo;
  83         struct inode vfs_inode;
  84         union {
  85                 struct hlist_node       plink;
  86                 struct llist_node       lnode;  /* delayed free */
  87         };
  88 } ____cacheline_aligned_in_smp;
  89
  90 /* au_pin flags */
  91 #define AuPin_DI_LOCKED         1
  92 #define AuPin_MNT_WRITE         (1 << 1)
  93 #define au_ftest_pin(flags, name)       ((flags) & AuPin_##name)
  94 #define au_fset_pin(flags, name) \
  95         do { (flags) |= AuPin_##name; } while (0)
  96 #define au_fclr_pin(flags, name) \
  97         do { (flags) &= ~AuPin_##name; } while (0)
  98
  99 struct au_pin {
 100         /* input */
 101         struct dentry *dentry;
 102         unsigned int udba;
 103         unsigned char lsc_di, lsc_hi, flags;
 104         aufs_bindex_t bindex;
 105
 106         /* output */
 107         struct dentry *parent;
 108         struct au_hinode *hdir;
 109         struct vfsmount *h_mnt;
 110
 111         /* temporary unlock/relock for copyup */
 112         struct dentry *h_dentry, *h_parent;
 113         struct au_branch *br;
 114         struct task_struct *task;
 115 };
 116
 117 void au_pin_hdir_unlock(struct au_pin *p);
 118 int au_pin_hdir_lock(struct au_pin *p);
 119 int au_pin_hdir_relock(struct au_pin *p);
 120 void au_pin_hdir_acquire_nest(struct au_pin *p);
 121 void au_pin_hdir_release(struct au_pin *p);
 122
 123 /* ---------------------------------------------------------------------- */
 124
 125 static inline struct au_iinfo *au_ii(struct inode *inode)
 126 {
 127         BUG_ON(is_bad_inode(inode));
 128         return &(container_of(inode, struct au_icntnr, vfs_inode)->iinfo);
 129 }
 130
 131 /* ---------------------------------------------------------------------- */
 132
 133 /* inode.c */
 134 struct inode *au_igrab(struct inode *inode);
 135 void au_refresh_iop(struct inode *inode, int force_getattr);
 136 int au_refresh_hinode_self(struct inode *inode);
 137 int au_refresh_hinode(struct inode *inode, struct dentry *dentry);
 138 int au_ino(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
 139            unsigned int d_type, ino_t *ino);
 140 struct inode *au_new_inode(struct dentry *dentry, int must_new);
 141 int au_test_ro(struct super_block *sb, aufs_bindex_t bindex,
 142                struct inode *inode);
 143 int au_test_h_perm(struct inode *h_inode, int mask);
 144 int au_test_h_perm_sio(struct inode *h_inode, int mask);
 145
 146 static inline int au_wh_ino(struct super_block *sb, aufs_bindex_t bindex,
 147                             ino_t h_ino, unsigned int d_type, ino_t *ino)
 148 {
 149 #ifdef CONFIG_AUFS_SHWH
 150         return au_ino(sb, bindex, h_ino, d_type, ino);
 151 #else
 152         return 0;
 153 #endif
 154 }
 155
 156 /* i_op.c */
 157 enum {
 158         AuIop_SYMLINK,
 159         AuIop_DIR,
 160         AuIop_OTHER,
 161         AuIop_Last
 162 };
 163 extern struct inode_operations aufs_iop[AuIop_Last],
 164         aufs_iop_nogetattr[AuIop_Last];
 165
 166 /* au_wr_dir flags */
 167 #define AuWrDir_ADD_ENTRY       1
 168 #define AuWrDir_ISDIR           (1 << 1)
 169 #define AuWrDir_TMPFILE         (1 << 2)
 170 #define au_ftest_wrdir(flags, name)     ((flags) & AuWrDir_##name)
 171 #define au_fset_wrdir(flags, name) \
 172         do { (flags) |= AuWrDir_##name; } while (0)
 173 #define au_fclr_wrdir(flags, name) \
 174         do { (flags) &= ~AuWrDir_##name; } while (0)
 175
 176 struct au_wr_dir_args {
 177         aufs_bindex_t force_btgt;
 178         unsigned char flags;
 179 };
 180 int au_wr_dir(struct dentry *dentry, struct dentry *src_dentry,
 181               struct au_wr_dir_args *args);
 182
 183 struct dentry *au_pinned_h_parent(struct au_pin *pin);
 184 void au_pin_init(struct au_pin *pin, struct dentry *dentry,
 185                  aufs_bindex_t bindex, int lsc_di, int lsc_hi,
 186                  unsigned int udba, unsigned char flags);
 187 int au_pin(struct au_pin *pin, struct dentry *dentry, aufs_bindex_t bindex,
 188            unsigned int udba, unsigned char flags) __must_check;
 189 int au_do_pin(struct au_pin *pin) __must_check;
 190 void au_unpin(struct au_pin *pin);
 191 int au_reval_for_attr(struct dentry *dentry, unsigned int sigen);
 192
 193 #define AuIcpup_DID_CPUP        1
 194 #define au_ftest_icpup(flags, name)     ((flags) & AuIcpup_##name)
 195 #define au_fset_icpup(flags, name) \
 196         do { (flags) |= AuIcpup_##name; } while (0)
 197 #define au_fclr_icpup(flags, name) \
 198         do { (flags) &= ~AuIcpup_##name; } while (0)
 199
 200 struct au_icpup_args {
 201         unsigned char flags;
 202         unsigned char pin_flags;
 203         aufs_bindex_t btgt;
 204         unsigned int udba;
 205         struct au_pin pin;
 206         struct path h_path;
 207         struct inode *h_inode;
 208 };
 209
 210 int au_pin_and_icpup(struct dentry *dentry, struct iattr *ia,
 211                      struct au_icpup_args *a);
 212
 213 int au_h_path_getattr(struct dentry *dentry, int force, struct path *h_path);
 214
 215 /* i_op_add.c */
 216 int au_may_add(struct dentry *dentry, aufs_bindex_t bindex,
 217                struct dentry *h_parent, int isdir);
 218 int aufs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
 219                dev_t dev);
 220 int aufs_symlink(struct inode *dir, struct dentry *dentry, const char *symname);
 221 int aufs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 222                 bool want_excl);
 223 struct vfsub_aopen_args;
 224 int au_aopen_or_create(struct inode *dir, struct dentry *dentry,
 225                        struct vfsub_aopen_args *args);
 226 int aufs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode);
 227 int aufs_link(struct dentry *src_dentry, struct inode *dir,
 228               struct dentry *dentry);
 229 int aufs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode);
 230
 231 /* i_op_del.c */
 232 int au_wr_dir_need_wh(struct dentry *dentry, int isdir, aufs_bindex_t *bcpup);
 233 int au_may_del(struct dentry *dentry, aufs_bindex_t bindex,
 234                struct dentry *h_parent, int isdir);
 235 int aufs_unlink(struct inode *dir, struct dentry *dentry);
 236 int aufs_rmdir(struct inode *dir, struct dentry *dentry);
 237
 238 /* i_op_ren.c */
 239 int au_wbr(struct dentry *dentry, aufs_bindex_t btgt);
 240 int aufs_rename(struct inode *src_dir, struct dentry *src_dentry,
 241                 struct inode *dir, struct dentry *dentry);
 242
 243 /* iinfo.c */
 244 struct inode *au_h_iptr(struct inode *inode, aufs_bindex_t bindex);
 245 void au_hiput(struct au_hinode *hinode);
 246 void au_set_hi_wh(struct inode *inode, aufs_bindex_t bindex,
 247                   struct dentry *h_wh);
 248 unsigned int au_hi_flags(struct inode *inode, int isdir);
 249
 250 /* hinode flags */
 251 #define AuHi_XINO       1
 252 #define AuHi_HNOTIFY    (1 << 1)
 253 #define au_ftest_hi(flags, name)        ((flags) & AuHi_##name)
 254 #define au_fset_hi(flags, name) \
 255         do { (flags) |= AuHi_##name; } while (0)
 256 #define au_fclr_hi(flags, name) \
 257         do { (flags) &= ~AuHi_##name; } while (0)
 258
 259 #ifndef CONFIG_AUFS_HNOTIFY
 260 #undef AuHi_HNOTIFY
 261 #define AuHi_HNOTIFY    0
 262 #endif
 263
 264 void au_set_h_iptr(struct inode *inode, aufs_bindex_t bindex,
 265                    struct inode *h_inode, unsigned int flags);
 266
 267 void au_update_iigen(struct inode *inode, int half);
 268 void au_update_ibrange(struct inode *inode, int do_put_zero);
 269
 270 void au_icntnr_init_once(void *_c);
 271 void au_hinode_init(struct au_hinode *hinode);
 272 int au_iinfo_init(struct inode *inode);
 273 void au_iinfo_fin(struct inode *inode);
 274 int au_hinode_realloc(struct au_iinfo *iinfo, int nbr, int may_shrink);
 275
 276 #ifdef CONFIG_PROC_FS
 277 /* plink.c */
 278 int au_plink_maint(struct super_block *sb, int flags);
 279 struct au_sbinfo;
 280 void au_plink_maint_leave(struct au_sbinfo *sbinfo);
 281 int au_plink_maint_enter(struct super_block *sb);
 282 #ifdef CONFIG_AUFS_DEBUG
 283 void au_plink_list(struct super_block *sb);
 284 #else
 285 AuStubVoid(au_plink_list, struct super_block *sb)
 286 #endif
 287 int au_plink_test(struct inode *inode);
 288 struct dentry *au_plink_lkup(struct inode *inode, aufs_bindex_t bindex);
 289 void au_plink_append(struct inode *inode, aufs_bindex_t bindex,
 290                      struct dentry *h_dentry);
 291 void au_plink_put(struct super_block *sb, int verbose);
 292 void au_plink_clean(struct super_block *sb, int verbose);
 293 void au_plink_half_refresh(struct super_block *sb, aufs_bindex_t br_id);
 294 #else
 295 AuStubInt0(au_plink_maint, struct super_block *sb, int flags);
 296 AuStubVoid(au_plink_maint_leave, struct au_sbinfo *sbinfo);
 297 AuStubInt0(au_plink_maint_enter, struct super_block *sb);
 298 AuStubVoid(au_plink_list, struct super_block *sb);
 299 AuStubInt0(au_plink_test, struct inode *inode);
 300 AuStub(struct dentry *, au_plink_lkup, return NULL,
 301        struct inode *inode, aufs_bindex_t bindex);
 302 AuStubVoid(au_plink_append, struct inode *inode, aufs_bindex_t bindex,
 303            struct dentry *h_dentry);
 304 AuStubVoid(au_plink_put, struct super_block *sb, int verbose);
 305 AuStubVoid(au_plink_clean, struct super_block *sb, int verbose);
 306 AuStubVoid(au_plink_half_refresh, struct super_block *sb, aufs_bindex_t br_id);
 307 #endif /* CONFIG_PROC_FS */
 308
 309 #ifdef CONFIG_AUFS_XATTR
 310 /* xattr.c */
 311 int au_cpup_xattr(struct dentry *h_dst, struct dentry *h_src, int ignore_flags,
 312                   unsigned int verbose);
 313 ssize_t aufs_listxattr(struct dentry *dentry, char *list, size_t size);
 314 void au_xattr_init(struct super_block *sb);
 315 #else
 316 AuStubInt0(au_cpup_xattr, struct dentry *h_dst, struct dentry *h_src,
 317            int ignore_flags, unsigned int verbose);
 318 AuStubVoid(au_xattr_init, struct super_block *sb);
 319 #endif
 320
 321 #ifdef CONFIG_FS_POSIX_ACL
 322 struct posix_acl *aufs_get_acl(struct inode *inode, int type);
 323 int aufs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 324 #endif
 325
 326 #if IS_ENABLED(CONFIG_AUFS_XATTR) || IS_ENABLED(CONFIG_FS_POSIX_ACL)
 327 enum {
 328         AU_XATTR_SET,
 329         AU_XATTR_REMOVE,
 330         AU_ACL_SET
 331 };
 332
 333 struct au_srxattr {
 334         int type;
 335         union {
 336                 struct {
 337                         const char      *name;
 338                         const void      *value;
 339                         size_t          size;
 340                         int             flags;
 341                 } set;
 342                 struct {
 343                         const char      *name;
 344                 } remove;
 345                 struct {
 346                         struct posix_acl *acl;
 347                         int             type;
 348                 } acl_set;
 349         } u;
 350 };
 351 ssize_t au_srxattr(struct dentry *dentry, struct inode *inode,
 352                    struct au_srxattr *arg);
 353 #endif
 354
 355 /* ---------------------------------------------------------------------- */
 356
 357 /* lock subclass for iinfo */
 358 enum {
 359         AuLsc_II_CHILD,         /* child first */
 360         AuLsc_II_CHILD2,        /* rename(2), link(2), and cpup at hnotify */
 361         AuLsc_II_CHILD3,        /* copyup dirs */
 362         AuLsc_II_PARENT,        /* see AuLsc_I_PARENT in vfsub.h */
 363         AuLsc_II_PARENT2,
 364         AuLsc_II_PARENT3,       /* copyup dirs */
 365         AuLsc_II_NEW_CHILD
 366 };
 367
 368 /*
 369  * ii_read_lock_child, ii_write_lock_child,
 370  * ii_read_lock_child2, ii_write_lock_child2,
 371  * ii_read_lock_child3, ii_write_lock_child3,
 372  * ii_read_lock_parent, ii_write_lock_parent,
 373  * ii_read_lock_parent2, ii_write_lock_parent2,
 374  * ii_read_lock_parent3, ii_write_lock_parent3,
 375  * ii_read_lock_new_child, ii_write_lock_new_child,
 376  */
 377 #define AuReadLockFunc(name, lsc) \
 378 static inline void ii_read_lock_##name(struct inode *i) \
 379 { \
 380         au_rw_read_lock_nested(&au_ii(i)->ii_rwsem, AuLsc_II_##lsc); \
 381 }
 382
 383 #define AuWriteLockFunc(name, lsc) \
 384 static inline void ii_write_lock_##name(struct inode *i) \
 385 { \
 386         au_rw_write_lock_nested(&au_ii(i)->ii_rwsem, AuLsc_II_##lsc); \
 387 }
 388
 389 #define AuRWLockFuncs(name, lsc) \
 390         AuReadLockFunc(name, lsc) \
 391         AuWriteLockFunc(name, lsc)
 392
 393 AuRWLockFuncs(child, CHILD);
 394 AuRWLockFuncs(child2, CHILD2);
 395 AuRWLockFuncs(child3, CHILD3);
 396 AuRWLockFuncs(parent, PARENT);
 397 AuRWLockFuncs(parent2, PARENT2);
 398 AuRWLockFuncs(parent3, PARENT3);
 399 AuRWLockFuncs(new_child, NEW_CHILD);
 400
 401 #undef AuReadLockFunc
 402 #undef AuWriteLockFunc
 403 #undef AuRWLockFuncs
 404
 405 /*
 406  * ii_read_unlock, ii_write_unlock, ii_downgrade_lock
 407  */
 408 AuSimpleUnlockRwsemFuncs(ii, struct inode *i, &au_ii(i)->ii_rwsem);
 409
 410 #define IiMustNoWaiters(i)      AuRwMustNoWaiters(&au_ii(i)->ii_rwsem)
 411 #define IiMustAnyLock(i)        AuRwMustAnyLock(&au_ii(i)->ii_rwsem)
 412 #define IiMustWriteLock(i)      AuRwMustWriteLock(&au_ii(i)->ii_rwsem)
 413
 414 /* ---------------------------------------------------------------------- */
 415
 416 static inline void au_icntnr_init(struct au_icntnr *c)
 417 {
 418 #ifdef CONFIG_AUFS_DEBUG
 419         c->vfs_inode.i_mode = 0;
 420 #endif
 421 }
 422
 423 static inline unsigned int au_iigen(struct inode *inode, unsigned int *igflags)
 424 {
 425         unsigned int gen;
 426         struct au_iinfo *iinfo;
 427         struct au_iigen *iigen;
 428
 429         iinfo = au_ii(inode);
 430         iigen = &iinfo->ii_generation;
 431         spin_lock(&iigen->ig_spin);
 432         if (igflags)
 433                 *igflags = iigen->ig_flags;
 434         gen = iigen->ig_generation;
 435         spin_unlock(&iigen->ig_spin);
 436
 437         return gen;
 438 }
 439
 440 /* tiny test for inode number */
 441 /* tmpfs generation is too rough */
 442 static inline int au_test_higen(struct inode *inode, struct inode *h_inode)
 443 {
 444         struct au_iinfo *iinfo;
 445
 446         iinfo = au_ii(inode);
 447         AuRwMustAnyLock(&iinfo->ii_rwsem);
 448         return !(iinfo->ii_hsb1 == h_inode->i_sb
 449                  && iinfo->ii_higen == h_inode->i_generation);
 450 }
 451
 452 static inline void au_iigen_dec(struct inode *inode)
 453 {
 454         struct au_iinfo *iinfo;
 455         struct au_iigen *iigen;
 456
 457         iinfo = au_ii(inode);
 458         iigen = &iinfo->ii_generation;
 459         spin_lock(&iigen->ig_spin);
 460         iigen->ig_generation--;
 461         spin_unlock(&iigen->ig_spin);
 462 }
 463
 464 static inline int au_iigen_test(struct inode *inode, unsigned int sigen)
 465 {
 466         int err;
 467
 468         err = 0;
 469         if (unlikely(inode && au_iigen(inode, NULL) != sigen))
 470                 err = -EIO;
 471
 472         return err;
 473 }
 474
 475 /* ---------------------------------------------------------------------- */
 476
 477 static inline struct au_hinode *au_hinode(struct au_iinfo *iinfo,
 478                                           aufs_bindex_t bindex)
 479 {
 480         return iinfo->ii_hinode + bindex;
 481 }
 482
 483 static inline int au_is_bad_inode(struct inode *inode)
 484 {
 485         return !!(is_bad_inode(inode) || !au_hinode(au_ii(inode), 0));
 486 }
 487
 488 static inline aufs_bindex_t au_ii_br_id(struct inode *inode,
 489                                         aufs_bindex_t bindex)
 490 {
 491         IiMustAnyLock(inode);
 492         return au_hinode(au_ii(inode), bindex)->hi_id;
 493 }
 494
 495 static inline aufs_bindex_t au_ibtop(struct inode *inode)
 496 {
 497         IiMustAnyLock(inode);
 498         return au_ii(inode)->ii_btop;
 499 }
 500
 501 static inline aufs_bindex_t au_ibbot(struct inode *inode)
 502 {
 503         IiMustAnyLock(inode);
 504         return au_ii(inode)->ii_bbot;
 505 }
 506
 507 static inline struct au_vdir *au_ivdir(struct inode *inode)
 508 {
 509         IiMustAnyLock(inode);
 510         return au_ii(inode)->ii_vdir;
 511 }
 512
 513 static inline struct dentry *au_hi_wh(struct inode *inode, aufs_bindex_t bindex)
 514 {
 515         IiMustAnyLock(inode);
 516         return au_hinode(au_ii(inode), bindex)->hi_whdentry;
 517 }
 518
 519 static inline void au_set_ibtop(struct inode *inode, aufs_bindex_t bindex)
 520 {
 521         IiMustWriteLock(inode);
 522         au_ii(inode)->ii_btop = bindex;
 523 }
 524
 525 static inline void au_set_ibbot(struct inode *inode, aufs_bindex_t bindex)
 526 {
 527         IiMustWriteLock(inode);
 528         au_ii(inode)->ii_bbot = bindex;
 529 }
 530
 531 static inline void au_set_ivdir(struct inode *inode, struct au_vdir *vdir)
 532 {
 533         IiMustWriteLock(inode);
 534         au_ii(inode)->ii_vdir = vdir;
 535 }
 536
 537 static inline struct au_hinode *au_hi(struct inode *inode, aufs_bindex_t bindex)
 538 {
 539         IiMustAnyLock(inode);
 540         return au_hinode(au_ii(inode), bindex);
 541 }
 542
 543 /* ---------------------------------------------------------------------- */
 544
 545 static inline struct dentry *au_pinned_parent(struct au_pin *pin)
 546 {
 547         if (pin)
 548                 return pin->parent;
 549         return NULL;
 550 }
 551
 552 static inline struct inode *au_pinned_h_dir(struct au_pin *pin)
 553 {
 554         if (pin && pin->hdir)
 555                 return pin->hdir->hi_inode;
 556         return NULL;
 557 }
 558
 559 static inline struct au_hinode *au_pinned_hdir(struct au_pin *pin)
 560 {
 561         if (pin)
 562                 return pin->hdir;
 563         return NULL;
 564 }
 565
 566 static inline void au_pin_set_dentry(struct au_pin *pin, struct dentry *dentry)
 567 {
 568         if (pin)
 569                 pin->dentry = dentry;
 570 }
 571
 572 static inline void au_pin_set_parent_lflag(struct au_pin *pin,
 573                                            unsigned char lflag)
 574 {
 575         if (pin) {
 576                 if (lflag)
 577                         au_fset_pin(pin->flags, DI_LOCKED);
 578                 else
 579                         au_fclr_pin(pin->flags, DI_LOCKED);
 580         }
 581 }
 582
 583 #if 0 /* reserved */
 584 static inline void au_pin_set_parent(struct au_pin *pin, struct dentry *parent)
 585 {
 586         if (pin) {
 587                 dput(pin->parent);
 588                 pin->parent = dget(parent);
 589         }
 590 }
 591 #endif
 592
 593 /* ---------------------------------------------------------------------- */
 594
 595 struct au_branch;
 596 #ifdef CONFIG_AUFS_HNOTIFY
 597 struct au_hnotify_op {
 598         void (*ctl)(struct au_hinode *hinode, int do_set);
 599         int (*alloc)(struct au_hinode *hinode);
 600
 601         /*
 602          * if it returns true, the the caller should free hinode->hi_notify,
 603          * otherwise ->free() frees it.
 604          */
 605         int (*free)(struct au_hinode *hinode,
 606                     struct au_hnotify *hn) __must_check;
 607
 608         void (*fin)(void);
 609         int (*init)(void);
 610
 611         int (*reset_br)(unsigned int udba, struct au_branch *br, int perm);
 612         void (*fin_br)(struct au_branch *br);
 613         int (*init_br)(struct au_branch *br, int perm);
 614 };
 615
 616 /* hnotify.c */
 617 int au_hn_alloc(struct au_hinode *hinode, struct inode *inode);
 618 void au_hn_free(struct au_hinode *hinode);
 619 void au_hn_ctl(struct au_hinode *hinode, int do_set);
 620 void au_hn_reset(struct inode *inode, unsigned int flags);
 621 int au_hnotify(struct inode *h_dir, struct au_hnotify *hnotify, u32 mask,
 622                struct qstr *h_child_qstr, struct inode *h_child_inode);
 623 int au_hnotify_reset_br(unsigned int udba, struct au_branch *br, int perm);
 624 int au_hnotify_init_br(struct au_branch *br, int perm);
 625 void au_hnotify_fin_br(struct au_branch *br);
 626 int __init au_hnotify_init(void);
 627 void au_hnotify_fin(void);
 628
 629 /* hfsnotify.c */
 630 extern const struct au_hnotify_op au_hnotify_op;
 631
 632 static inline
 633 void au_hn_init(struct au_hinode *hinode)
 634 {
 635         hinode->hi_notify = NULL;
 636 }
 637
 638 static inline struct au_hnotify *au_hn(struct au_hinode *hinode)
 639 {
 640         return hinode->hi_notify;
 641 }
 642
 643 #else
 644 AuStub(int, au_hn_alloc, return -EOPNOTSUPP,
 645        struct au_hinode *hinode __maybe_unused,
 646        struct inode *inode __maybe_unused)
 647 AuStub(struct au_hnotify *, au_hn, return NULL, struct au_hinode *hinode)
 648 AuStubVoid(au_hn_free, struct au_hinode *hinode __maybe_unused)
 649 AuStubVoid(au_hn_ctl, struct au_hinode *hinode __maybe_unused,
 650            int do_set __maybe_unused)
 651 AuStubVoid(au_hn_reset, struct inode *inode __maybe_unused,
 652            unsigned int flags __maybe_unused)
 653 AuStubInt0(au_hnotify_reset_br, unsigned int udba __maybe_unused,
 654            struct au_branch *br __maybe_unused,
 655            int perm __maybe_unused)
 656 AuStubInt0(au_hnotify_init_br, struct au_branch *br __maybe_unused,
 657            int perm __maybe_unused)
 658 AuStubVoid(au_hnotify_fin_br, struct au_branch *br __maybe_unused)
 659 AuStubInt0(__init au_hnotify_init, void)
 660 AuStubVoid(au_hnotify_fin, void)
 661 AuStubVoid(au_hn_init, struct au_hinode *hinode __maybe_unused)
 662 #endif /* CONFIG_AUFS_HNOTIFY */
 663
 664 static inline void au_hn_suspend(struct au_hinode *hdir)
 665 {
 666         au_hn_ctl(hdir, /*do_set*/0);
 667 }
 668
 669 static inline void au_hn_resume(struct au_hinode *hdir)
 670 {
 671         au_hn_ctl(hdir, /*do_set*/1);
 672 }
 673
 674 static inline void au_hn_inode_lock(struct au_hinode *hdir)
 675 {
 676         inode_lock(hdir->hi_inode);
 677         au_hn_suspend(hdir);
 678 }
 679
 680 static inline void au_hn_inode_lock_nested(struct au_hinode *hdir,
 681                                           unsigned int sc __maybe_unused)
 682 {
 683         inode_lock_nested(hdir->hi_inode, sc);
 684         au_hn_suspend(hdir);
 685 }
 686
 687 static inline void au_hn_inode_unlock(struct au_hinode *hdir)
 688 {
 689         au_hn_resume(hdir);
 690         inode_unlock(hdir->hi_inode);
 691 }
 692
 693 #endif /* __KERNEL__ */
 694 #endif /* __AUFS_INODE_H__ */