fs/aufs/inode.h

   1 /*
   2  * Copyright (C) 2005-2017 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         struct inode            *hn_aufs_inode; /* no get/put */
  39 #endif
  40 } ____cacheline_aligned_in_smp;
  41
  42 struct au_hinode {
  43         struct inode            *hi_inode;
  44         aufs_bindex_t           hi_id;
  45 #ifdef CONFIG_AUFS_HNOTIFY
  46         struct au_hnotify       *hi_notify;
  47 #endif
  48
  49         /* reference to the copied-up whiteout with get/put */
  50         struct dentry           *hi_whdentry;
  51 };
  52
  53 /* ig_flags */
  54 #define AuIG_HALF_REFRESHED             1
  55 #define au_ig_ftest(flags, name)        ((flags) & AuIG_##name)
  56 #define au_ig_fset(flags, name) \
  57         do { (flags) |= AuIG_##name; } while (0)
  58 #define au_ig_fclr(flags, name) \
  59         do { (flags) &= ~AuIG_##name; } while (0)
  60
  61 struct au_iigen {
  62         spinlock_t      ig_spin;
  63         __u32           ig_generation, ig_flags;
  64 };
  65
  66 struct au_vdir;
  67 struct au_iinfo {
  68         struct au_iigen         ii_generation;
  69         struct super_block      *ii_hsb1;       /* no get/put */
  70
  71         struct au_rwsem         ii_rwsem;
  72         aufs_bindex_t           ii_btop, ii_bbot;
  73         __u32                   ii_higen;
  74         struct au_hinode        *ii_hinode;
  75         struct au_vdir          *ii_vdir;
  76 };
  77
  78 struct au_icntnr {
  79         struct au_iinfo iinfo;
  80         struct inode vfs_inode;
  81         struct hlist_node plink;
  82 } ____cacheline_aligned_in_smp;
  83
  84 /* au_pin flags */
  85 #define AuPin_DI_LOCKED         1
  86 #define AuPin_MNT_WRITE         (1 << 1)
  87 #define au_ftest_pin(flags, name)       ((flags) & AuPin_##name)
  88 #define au_fset_pin(flags, name) \
  89         do { (flags) |= AuPin_##name; } while (0)
  90 #define au_fclr_pin(flags, name) \
  91         do { (flags) &= ~AuPin_##name; } while (0)
  92
  93 struct au_pin {
  94         /* input */
  95         struct dentry *dentry;
  96         unsigned int udba;
  97         unsigned char lsc_di, lsc_hi, flags;
  98         aufs_bindex_t bindex;
  99
 100         /* output */
 101         struct dentry *parent;
 102         struct au_hinode *hdir;
 103         struct vfsmount *h_mnt;
 104
 105         /* temporary unlock/relock for copyup */
 106         struct dentry *h_dentry, *h_parent;
 107         struct au_branch *br;
 108         struct task_struct *task;
 109 };
 110
 111 void au_pin_hdir_unlock(struct au_pin *p);
 112 int au_pin_hdir_lock(struct au_pin *p);
 113 int au_pin_hdir_relock(struct au_pin *p);
 114 void au_pin_hdir_acquire_nest(struct au_pin *p);
 115 void au_pin_hdir_release(struct au_pin *p);
 116
 117 /* ---------------------------------------------------------------------- */
 118
 119 static inline struct au_iinfo *au_ii(struct inode *inode)
 120 {
 121         BUG_ON(is_bad_inode(inode));
 122         return &(container_of(inode, struct au_icntnr, vfs_inode)->iinfo);
 123 }
 124
 125 /* ---------------------------------------------------------------------- */
 126
 127 /* inode.c */
 128 struct inode *au_igrab(struct inode *inode);
 129 void au_refresh_iop(struct inode *inode, int force_getattr);
 130 int au_refresh_hinode_self(struct inode *inode);
 131 int au_refresh_hinode(struct inode *inode, struct dentry *dentry);
 132 int au_ino(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
 133            unsigned int d_type, ino_t *ino);
 134 struct inode *au_new_inode(struct dentry *dentry, int must_new);
 135 int au_test_ro(struct super_block *sb, aufs_bindex_t bindex,
 136                struct inode *inode);
 137 int au_test_h_perm(struct inode *h_inode, int mask);
 138 int au_test_h_perm_sio(struct inode *h_inode, int mask);
 139
 140 static inline int au_wh_ino(struct super_block *sb, aufs_bindex_t bindex,
 141                             ino_t h_ino, unsigned int d_type, ino_t *ino)
 142 {
 143 #ifdef CONFIG_AUFS_SHWH
 144         return au_ino(sb, bindex, h_ino, d_type, ino);
 145 #else
 146         return 0;
 147 #endif
 148 }
 149
 150 /* i_op.c */
 151 enum {
 152         AuIop_SYMLINK,
 153         AuIop_DIR,
 154         AuIop_OTHER,
 155         AuIop_Last
 156 };
 157 extern struct inode_operations aufs_iop[AuIop_Last],
 158         aufs_iop_nogetattr[AuIop_Last];
 159
 160 /* au_wr_dir flags */
 161 #define AuWrDir_ADD_ENTRY       1
 162 #define AuWrDir_ISDIR           (1 << 1)
 163 #define AuWrDir_TMPFILE         (1 << 2)
 164 #define au_ftest_wrdir(flags, name)     ((flags) & AuWrDir_##name)
 165 #define au_fset_wrdir(flags, name) \
 166         do { (flags) |= AuWrDir_##name; } while (0)
 167 #define au_fclr_wrdir(flags, name) \
 168         do { (flags) &= ~AuWrDir_##name; } while (0)
 169
 170 struct au_wr_dir_args {
 171         aufs_bindex_t force_btgt;
 172         unsigned char flags;
 173 };
 174 int au_wr_dir(struct dentry *dentry, struct dentry *src_dentry,
 175               struct au_wr_dir_args *args);
 176
 177 struct dentry *au_pinned_h_parent(struct au_pin *pin);
 178 void au_pin_init(struct au_pin *pin, struct dentry *dentry,
 179                  aufs_bindex_t bindex, int lsc_di, int lsc_hi,
 180                  unsigned int udba, unsigned char flags);
 181 int au_pin(struct au_pin *pin, struct dentry *dentry, aufs_bindex_t bindex,
 182            unsigned int udba, unsigned char flags) __must_check;
 183 int au_do_pin(struct au_pin *pin) __must_check;
 184 void au_unpin(struct au_pin *pin);
 185 int au_reval_for_attr(struct dentry *dentry, unsigned int sigen);
 186
 187 #define AuIcpup_DID_CPUP        1
 188 #define au_ftest_icpup(flags, name)     ((flags) & AuIcpup_##name)
 189 #define au_fset_icpup(flags, name) \
 190         do { (flags) |= AuIcpup_##name; } while (0)
 191 #define au_fclr_icpup(flags, name) \
 192         do { (flags) &= ~AuIcpup_##name; } while (0)
 193
 194 struct au_icpup_args {
 195         unsigned char flags;
 196         unsigned char pin_flags;
 197         aufs_bindex_t btgt;
 198         unsigned int udba;
 199         struct au_pin pin;
 200         struct path h_path;
 201         struct inode *h_inode;
 202 };
 203
 204 int au_pin_and_icpup(struct dentry *dentry, struct iattr *ia,
 205                      struct au_icpup_args *a);
 206
 207 int au_h_path_getattr(struct dentry *dentry, int force, struct path *h_path,
 208                       int locked);
 209
 210 /* i_op_add.c */
 211 int au_may_add(struct dentry *dentry, aufs_bindex_t bindex,
 212                struct dentry *h_parent, int isdir);
 213 int aufs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
 214                dev_t dev);
 215 int aufs_symlink(struct inode *dir, struct dentry *dentry, const char *symname);
 216 int aufs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 217                 bool want_excl);
 218 struct vfsub_aopen_args;
 219 int au_aopen_or_create(struct inode *dir, struct dentry *dentry,
 220                        struct vfsub_aopen_args *args);
 221 int aufs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode);
 222 int aufs_link(struct dentry *src_dentry, struct inode *dir,
 223               struct dentry *dentry);
 224 int aufs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode);
 225
 226 /* i_op_del.c */
 227 int au_wr_dir_need_wh(struct dentry *dentry, int isdir, aufs_bindex_t *bcpup);
 228 int au_may_del(struct dentry *dentry, aufs_bindex_t bindex,
 229                struct dentry *h_parent, int isdir);
 230 int aufs_unlink(struct inode *dir, struct dentry *dentry);
 231 int aufs_rmdir(struct inode *dir, struct dentry *dentry);
 232
 233 /* i_op_ren.c */
 234 int au_wbr(struct dentry *dentry, aufs_bindex_t btgt);
 235 int aufs_rename(struct inode *src_dir, struct dentry *src_dentry,
 236                 struct inode *dir, struct dentry *dentry,
 237                 unsigned int flags);
 238
 239 /* iinfo.c */
 240 struct inode *au_h_iptr(struct inode *inode, aufs_bindex_t bindex);
 241 void au_hiput(struct au_hinode *hinode);
 242 void au_set_hi_wh(struct inode *inode, aufs_bindex_t bindex,
 243                   struct dentry *h_wh);
 244 unsigned int au_hi_flags(struct inode *inode, int isdir);
 245
 246 /* hinode flags */
 247 #define AuHi_XINO       1
 248 #define AuHi_HNOTIFY    (1 << 1)
 249 #define au_ftest_hi(flags, name)        ((flags) & AuHi_##name)
 250 #define au_fset_hi(flags, name) \
 251         do { (flags) |= AuHi_##name; } while (0)
 252 #define au_fclr_hi(flags, name) \
 253         do { (flags) &= ~AuHi_##name; } while (0)
 254
 255 #ifndef CONFIG_AUFS_HNOTIFY
 256 #undef AuHi_HNOTIFY
 257 #define AuHi_HNOTIFY    0
 258 #endif
 259
 260 void au_set_h_iptr(struct inode *inode, aufs_bindex_t bindex,
 261                    struct inode *h_inode, unsigned int flags);
 262
 263 void au_update_iigen(struct inode *inode, int half);
 264 void au_update_ibrange(struct inode *inode, int do_put_zero);
 265
 266 void au_icntnr_init_once(void *_c);
 267 void au_hinode_init(struct au_hinode *hinode);
 268 int au_iinfo_init(struct inode *inode);
 269 void au_iinfo_fin(struct inode *inode);
 270 int au_hinode_realloc(struct au_iinfo *iinfo, int nbr, int may_shrink);
 271
 272 #ifdef CONFIG_PROC_FS
 273 /* plink.c */
 274 int au_plink_maint(struct super_block *sb, int flags);
 275 struct au_sbinfo;
 276 void au_plink_maint_leave(struct au_sbinfo *sbinfo);
 277 int au_plink_maint_enter(struct super_block *sb);
 278 #ifdef CONFIG_AUFS_DEBUG
 279 void au_plink_list(struct super_block *sb);
 280 #else
 281 AuStubVoid(au_plink_list, struct super_block *sb)
 282 #endif
 283 int au_plink_test(struct inode *inode);
 284 struct dentry *au_plink_lkup(struct inode *inode, aufs_bindex_t bindex);
 285 void au_plink_append(struct inode *inode, aufs_bindex_t bindex,
 286                      struct dentry *h_dentry);
 287 void au_plink_put(struct super_block *sb, int verbose);
 288 void au_plink_clean(struct super_block *sb, int verbose);
 289 void au_plink_half_refresh(struct super_block *sb, aufs_bindex_t br_id);
 290 #else
 291 AuStubInt0(au_plink_maint, struct super_block *sb, int flags);
 292 AuStubVoid(au_plink_maint_leave, struct au_sbinfo *sbinfo);
 293 AuStubInt0(au_plink_maint_enter, struct super_block *sb);
 294 AuStubVoid(au_plink_list, struct super_block *sb);
 295 AuStubInt0(au_plink_test, struct inode *inode);
 296 AuStub(struct dentry *, au_plink_lkup, return NULL,
 297        struct inode *inode, aufs_bindex_t bindex);
 298 AuStubVoid(au_plink_append, struct inode *inode, aufs_bindex_t bindex,
 299            struct dentry *h_dentry);
 300 AuStubVoid(au_plink_put, struct super_block *sb, int verbose);
 301 AuStubVoid(au_plink_clean, struct super_block *sb, int verbose);
 302 AuStubVoid(au_plink_half_refresh, struct super_block *sb, aufs_bindex_t br_id);
 303 #endif /* CONFIG_PROC_FS */
 304
 305 #ifdef CONFIG_AUFS_XATTR
 306 /* xattr.c */
 307 int au_cpup_xattr(struct dentry *h_dst, struct dentry *h_src, int ignore_flags,
 308                   unsigned int verbose);
 309 ssize_t aufs_listxattr(struct dentry *dentry, char *list, size_t size);
 310 void au_xattr_init(struct super_block *sb);
 311 #else
 312 AuStubInt0(au_cpup_xattr, struct dentry *h_dst, struct dentry *h_src,
 313            int ignore_flags, unsigned int verbose);
 314 AuStubVoid(au_xattr_init, struct super_block *sb);
 315 #endif
 316
 317 #ifdef CONFIG_FS_POSIX_ACL
 318 struct posix_acl *aufs_get_acl(struct inode *inode, int type);
 319 int aufs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 320 #endif
 321
 322 #if IS_ENABLED(CONFIG_AUFS_XATTR) || IS_ENABLED(CONFIG_FS_POSIX_ACL)
 323 enum {
 324         AU_XATTR_SET,
 325         AU_ACL_SET
 326 };
 327
 328 struct au_sxattr {
 329         int type;
 330         union {
 331                 struct {
 332                         const char      *name;
 333                         const void      *value;
 334                         size_t          size;
 335                         int             flags;
 336                 } set;
 337                 struct {
 338                         struct posix_acl *acl;
 339                         int             type;
 340                 } acl_set;
 341         } u;
 342 };
 343 ssize_t au_sxattr(struct dentry *dentry, struct inode *inode,
 344                   struct au_sxattr *arg);
 345 #endif
 346
 347 /* ---------------------------------------------------------------------- */
 348
 349 /* lock subclass for iinfo */
 350 enum {
 351         AuLsc_II_CHILD,         /* child first */
 352         AuLsc_II_CHILD2,        /* rename(2), link(2), and cpup at hnotify */
 353         AuLsc_II_CHILD3,        /* copyup dirs */
 354         AuLsc_II_PARENT,        /* see AuLsc_I_PARENT in vfsub.h */
 355         AuLsc_II_PARENT2,
 356         AuLsc_II_PARENT3,       /* copyup dirs */
 357         AuLsc_II_NEW_CHILD
 358 };
 359
 360 /*
 361  * ii_read_lock_child, ii_write_lock_child,
 362  * ii_read_lock_child2, ii_write_lock_child2,
 363  * ii_read_lock_child3, ii_write_lock_child3,
 364  * ii_read_lock_parent, ii_write_lock_parent,
 365  * ii_read_lock_parent2, ii_write_lock_parent2,
 366  * ii_read_lock_parent3, ii_write_lock_parent3,
 367  * ii_read_lock_new_child, ii_write_lock_new_child,
 368  */
 369 #define AuReadLockFunc(name, lsc) \
 370 static inline void ii_read_lock_##name(struct inode *i) \
 371 { \
 372         au_rw_read_lock_nested(&au_ii(i)->ii_rwsem, AuLsc_II_##lsc); \
 373 }
 374
 375 #define AuWriteLockFunc(name, lsc) \
 376 static inline void ii_write_lock_##name(struct inode *i) \
 377 { \
 378         au_rw_write_lock_nested(&au_ii(i)->ii_rwsem, AuLsc_II_##lsc); \
 379 }
 380
 381 #define AuRWLockFuncs(name, lsc) \
 382         AuReadLockFunc(name, lsc) \
 383         AuWriteLockFunc(name, lsc)
 384
 385 AuRWLockFuncs(child, CHILD);
 386 AuRWLockFuncs(child2, CHILD2);
 387 AuRWLockFuncs(child3, CHILD3);
 388 AuRWLockFuncs(parent, PARENT);
 389 AuRWLockFuncs(parent2, PARENT2);
 390 AuRWLockFuncs(parent3, PARENT3);
 391 AuRWLockFuncs(new_child, NEW_CHILD);
 392
 393 #undef AuReadLockFunc
 394 #undef AuWriteLockFunc
 395 #undef AuRWLockFuncs
 396
 397 /*
 398  * ii_read_unlock, ii_write_unlock, ii_downgrade_lock
 399  */
 400 AuSimpleUnlockRwsemFuncs(ii, struct inode *i, &au_ii(i)->ii_rwsem);
 401
 402 #define IiMustNoWaiters(i)      AuRwMustNoWaiters(&au_ii(i)->ii_rwsem)
 403 #define IiMustAnyLock(i)        AuRwMustAnyLock(&au_ii(i)->ii_rwsem)
 404 #define IiMustWriteLock(i)      AuRwMustWriteLock(&au_ii(i)->ii_rwsem)
 405
 406 /* ---------------------------------------------------------------------- */
 407
 408 static inline void au_icntnr_init(struct au_icntnr *c)
 409 {
 410 #ifdef CONFIG_AUFS_DEBUG
 411         c->vfs_inode.i_mode = 0;
 412 #endif
 413 }
 414
 415 static inline unsigned int au_iigen(struct inode *inode, unsigned int *igflags)
 416 {
 417         unsigned int gen;
 418         struct au_iinfo *iinfo;
 419         struct au_iigen *iigen;
 420
 421         iinfo = au_ii(inode);
 422         iigen = &iinfo->ii_generation;
 423         spin_lock(&iigen->ig_spin);
 424         if (igflags)
 425                 *igflags = iigen->ig_flags;
 426         gen = iigen->ig_generation;
 427         spin_unlock(&iigen->ig_spin);
 428
 429         return gen;
 430 }
 431
 432 /* tiny test for inode number */
 433 /* tmpfs generation is too rough */
 434 static inline int au_test_higen(struct inode *inode, struct inode *h_inode)
 435 {
 436         struct au_iinfo *iinfo;
 437
 438         iinfo = au_ii(inode);
 439         AuRwMustAnyLock(&iinfo->ii_rwsem);
 440         return !(iinfo->ii_hsb1 == h_inode->i_sb
 441                  && iinfo->ii_higen == h_inode->i_generation);
 442 }
 443
 444 static inline void au_iigen_dec(struct inode *inode)
 445 {
 446         struct au_iinfo *iinfo;
 447         struct au_iigen *iigen;
 448
 449         iinfo = au_ii(inode);
 450         iigen = &iinfo->ii_generation;
 451         spin_lock(&iigen->ig_spin);
 452         iigen->ig_generation--;
 453         spin_unlock(&iigen->ig_spin);
 454 }
 455
 456 static inline int au_iigen_test(struct inode *inode, unsigned int sigen)
 457 {
 458         int err;
 459
 460         err = 0;
 461         if (unlikely(inode && au_iigen(inode, NULL) != sigen))
 462                 err = -EIO;
 463
 464         return err;
 465 }
 466
 467 /* ---------------------------------------------------------------------- */
 468
 469 static inline struct au_hinode *au_hinode(struct au_iinfo *iinfo,
 470                                           aufs_bindex_t bindex)
 471 {
 472         return iinfo->ii_hinode + bindex;
 473 }
 474
 475 static inline int au_is_bad_inode(struct inode *inode)
 476 {
 477         return !!(is_bad_inode(inode) || !au_hinode(au_ii(inode), 0));
 478 }
 479
 480 static inline aufs_bindex_t au_ii_br_id(struct inode *inode,
 481                                         aufs_bindex_t bindex)
 482 {
 483         IiMustAnyLock(inode);
 484         return au_hinode(au_ii(inode), bindex)->hi_id;
 485 }
 486
 487 static inline aufs_bindex_t au_ibtop(struct inode *inode)
 488 {
 489         IiMustAnyLock(inode);
 490         return au_ii(inode)->ii_btop;
 491 }
 492
 493 static inline aufs_bindex_t au_ibbot(struct inode *inode)
 494 {
 495         IiMustAnyLock(inode);
 496         return au_ii(inode)->ii_bbot;
 497 }
 498
 499 static inline struct au_vdir *au_ivdir(struct inode *inode)
 500 {
 501         IiMustAnyLock(inode);
 502         return au_ii(inode)->ii_vdir;
 503 }
 504
 505 static inline struct dentry *au_hi_wh(struct inode *inode, aufs_bindex_t bindex)
 506 {
 507         IiMustAnyLock(inode);
 508         return au_hinode(au_ii(inode), bindex)->hi_whdentry;
 509 }
 510
 511 static inline void au_set_ibtop(struct inode *inode, aufs_bindex_t bindex)
 512 {
 513         IiMustWriteLock(inode);
 514         au_ii(inode)->ii_btop = bindex;
 515 }
 516
 517 static inline void au_set_ibbot(struct inode *inode, aufs_bindex_t bindex)
 518 {
 519         IiMustWriteLock(inode);
 520         au_ii(inode)->ii_bbot = bindex;
 521 }
 522
 523 static inline void au_set_ivdir(struct inode *inode, struct au_vdir *vdir)
 524 {
 525         IiMustWriteLock(inode);
 526         au_ii(inode)->ii_vdir = vdir;
 527 }
 528
 529 static inline struct au_hinode *au_hi(struct inode *inode, aufs_bindex_t bindex)
 530 {
 531         IiMustAnyLock(inode);
 532         return au_hinode(au_ii(inode), bindex);
 533 }
 534
 535 /* ---------------------------------------------------------------------- */
 536
 537 static inline struct dentry *au_pinned_parent(struct au_pin *pin)
 538 {
 539         if (pin)
 540                 return pin->parent;
 541         return NULL;
 542 }
 543
 544 static inline struct inode *au_pinned_h_dir(struct au_pin *pin)
 545 {
 546         if (pin && pin->hdir)
 547                 return pin->hdir->hi_inode;
 548         return NULL;
 549 }
 550
 551 static inline struct au_hinode *au_pinned_hdir(struct au_pin *pin)
 552 {
 553         if (pin)
 554                 return pin->hdir;
 555         return NULL;
 556 }
 557
 558 static inline void au_pin_set_dentry(struct au_pin *pin, struct dentry *dentry)
 559 {
 560         if (pin)
 561                 pin->dentry = dentry;
 562 }
 563
 564 static inline void au_pin_set_parent_lflag(struct au_pin *pin,
 565                                            unsigned char lflag)
 566 {
 567         if (pin) {
 568                 if (lflag)
 569                         au_fset_pin(pin->flags, DI_LOCKED);
 570                 else
 571                         au_fclr_pin(pin->flags, DI_LOCKED);
 572         }
 573 }
 574
 575 #if 0 /* reserved */
 576 static inline void au_pin_set_parent(struct au_pin *pin, struct dentry *parent)
 577 {
 578         if (pin) {
 579                 dput(pin->parent);
 580                 pin->parent = dget(parent);
 581         }
 582 }
 583 #endif
 584
 585 /* ---------------------------------------------------------------------- */
 586
 587 struct au_branch;
 588 #ifdef CONFIG_AUFS_HNOTIFY
 589 struct au_hnotify_op {
 590         void (*ctl)(struct au_hinode *hinode, int do_set);
 591         int (*alloc)(struct au_hinode *hinode);
 592
 593         /*
 594          * if it returns true, the the caller should free hinode->hi_notify,
 595          * otherwise ->free() frees it.
 596          */
 597         int (*free)(struct au_hinode *hinode,
 598                     struct au_hnotify *hn) __must_check;
 599
 600         void (*fin)(void);
 601         int (*init)(void);
 602
 603         int (*reset_br)(unsigned int udba, struct au_branch *br, int perm);
 604         void (*fin_br)(struct au_branch *br);
 605         int (*init_br)(struct au_branch *br, int perm);
 606 };
 607
 608 /* hnotify.c */
 609 int au_hn_alloc(struct au_hinode *hinode, struct inode *inode);
 610 void au_hn_free(struct au_hinode *hinode);
 611 void au_hn_ctl(struct au_hinode *hinode, int do_set);
 612 void au_hn_reset(struct inode *inode, unsigned int flags);
 613 int au_hnotify(struct inode *h_dir, struct au_hnotify *hnotify, u32 mask,
 614                struct qstr *h_child_qstr, struct inode *h_child_inode);
 615 int au_hnotify_reset_br(unsigned int udba, struct au_branch *br, int perm);
 616 int au_hnotify_init_br(struct au_branch *br, int perm);
 617 void au_hnotify_fin_br(struct au_branch *br);
 618 int __init au_hnotify_init(void);
 619 void au_hnotify_fin(void);
 620
 621 /* hfsnotify.c */
 622 extern const struct au_hnotify_op au_hnotify_op;
 623
 624 static inline
 625 void au_hn_init(struct au_hinode *hinode)
 626 {
 627         hinode->hi_notify = NULL;
 628 }
 629
 630 static inline struct au_hnotify *au_hn(struct au_hinode *hinode)
 631 {
 632         return hinode->hi_notify;
 633 }
 634
 635 #else
 636 AuStub(int, au_hn_alloc, return -EOPNOTSUPP,
 637        struct au_hinode *hinode __maybe_unused,
 638        struct inode *inode __maybe_unused)
 639 AuStub(struct au_hnotify *, au_hn, return NULL, struct au_hinode *hinode)
 640 AuStubVoid(au_hn_free, struct au_hinode *hinode __maybe_unused)
 641 AuStubVoid(au_hn_ctl, struct au_hinode *hinode __maybe_unused,
 642            int do_set __maybe_unused)
 643 AuStubVoid(au_hn_reset, struct inode *inode __maybe_unused,
 644            unsigned int flags __maybe_unused)
 645 AuStubInt0(au_hnotify_reset_br, unsigned int udba __maybe_unused,
 646            struct au_branch *br __maybe_unused,
 647            int perm __maybe_unused)
 648 AuStubInt0(au_hnotify_init_br, struct au_branch *br __maybe_unused,
 649            int perm __maybe_unused)
 650 AuStubVoid(au_hnotify_fin_br, struct au_branch *br __maybe_unused)
 651 AuStubInt0(__init au_hnotify_init, void)
 652 AuStubVoid(au_hnotify_fin, void)
 653 AuStubVoid(au_hn_init, struct au_hinode *hinode __maybe_unused)
 654 #endif /* CONFIG_AUFS_HNOTIFY */
 655
 656 static inline void au_hn_suspend(struct au_hinode *hdir)
 657 {
 658         au_hn_ctl(hdir, /*do_set*/0);
 659 }
 660
 661 static inline void au_hn_resume(struct au_hinode *hdir)
 662 {
 663         au_hn_ctl(hdir, /*do_set*/1);
 664 }
 665
 666 static inline void au_hn_inode_lock(struct au_hinode *hdir)
 667 {
 668         inode_lock(hdir->hi_inode);
 669         au_hn_suspend(hdir);
 670 }
 671
 672 static inline void au_hn_inode_lock_nested(struct au_hinode *hdir,
 673                                           unsigned int sc __maybe_unused)
 674 {
 675         inode_lock_nested(hdir->hi_inode, sc);
 676         au_hn_suspend(hdir);
 677 }
 678
 679 static inline void au_hn_inode_unlock(struct au_hinode *hdir)
 680 {
 681         au_hn_resume(hdir);
 682         inode_unlock(hdir->hi_inode);
 683 }
 684
 685 #endif /* __KERNEL__ */
 686 #endif /* __AUFS_INODE_H__ */