fs/aufs/super.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  * super_block operations
  20  */
  21
  22 #ifndef __AUFS_SUPER_H__
  23 #define __AUFS_SUPER_H__
  24
  25 #ifdef __KERNEL__
  26
  27 #include <linux/fs.h>
  28 #include <linux/kobject.h>
  29 #include "rwsem.h"
  30 #include "spl.h"
  31 #include "wkq.h"
  32
  33 /* policies to select one among multiple writable branches */
  34 struct au_wbr_copyup_operations {
  35         int (*copyup)(struct dentry *dentry);
  36 };
  37
  38 #define AuWbr_DIR       1               /* target is a dir */
  39 #define AuWbr_PARENT    (1 << 1)        /* always require a parent */
  40
  41 #define au_ftest_wbr(flags, name)       ((flags) & AuWbr_##name)
  42 #define au_fset_wbr(flags, name)        { (flags) |= AuWbr_##name; }
  43 #define au_fclr_wbr(flags, name)        { (flags) &= ~AuWbr_##name; }
  44
  45 struct au_wbr_create_operations {
  46         int (*create)(struct dentry *dentry, unsigned int flags);
  47         int (*init)(struct super_block *sb);
  48         int (*fin)(struct super_block *sb);
  49 };
  50
  51 struct au_wbr_mfs {
  52         struct mutex    mfs_lock; /* protect this structure */
  53         unsigned long   mfs_jiffy;
  54         unsigned long   mfs_expire;
  55         aufs_bindex_t   mfs_bindex;
  56
  57         unsigned long long      mfsrr_bytes;
  58         unsigned long long      mfsrr_watermark;
  59 };
  60
  61 #define AuPlink_NHASH 100
  62 static inline int au_plink_hash(ino_t ino)
  63 {
  64         return ino % AuPlink_NHASH;
  65 }
  66
  67 /* File-based Hierarchical Storage Management */
  68 struct au_fhsm {
  69 #ifdef CONFIG_AUFS_FHSM
  70         /* allow only one process who can receive the notification */
  71         spinlock_t              fhsm_spin;
  72         pid_t                   fhsm_pid;
  73         wait_queue_head_t       fhsm_wqh;
  74         atomic_t                fhsm_readable;
  75
  76         /* these are protected by si_rwsem */
  77         unsigned long           fhsm_expire;
  78         aufs_bindex_t           fhsm_bottom;
  79 #endif
  80 };
  81
  82 struct au_branch;
  83 struct au_sbinfo {
  84         /* nowait tasks in the system-wide workqueue */
  85         struct au_nowait_tasks  si_nowait;
  86
  87         /*
  88          * tried sb->s_umount, but failed due to the dependecy between i_mutex.
  89          * rwsem for au_sbinfo is necessary.
  90          */
  91         struct au_rwsem         si_rwsem;
  92
  93         /*
  94          * dirty approach to protect sb->sb_inodes and ->s_files (gone) from
  95          * remount.
  96          */
  97         struct percpu_counter   si_ninodes, si_nfiles;
  98
  99         /* branch management */
 100         unsigned int            si_generation;
 101
 102         /* see AuSi_ flags */
 103         unsigned char           au_si_status;
 104
 105         aufs_bindex_t           si_bbot;
 106
 107         /* dirty trick to keep br_id plus */
 108         unsigned int            si_last_br_id :
 109                                 sizeof(aufs_bindex_t) * BITS_PER_BYTE - 1;
 110         struct au_branch        **si_branch;
 111
 112         /* policy to select a writable branch */
 113         unsigned char           si_wbr_copyup;
 114         unsigned char           si_wbr_create;
 115         struct au_wbr_copyup_operations *si_wbr_copyup_ops;
 116         struct au_wbr_create_operations *si_wbr_create_ops;
 117
 118         /* round robin */
 119         atomic_t                si_wbr_rr_next;
 120
 121         /* most free space */
 122         struct au_wbr_mfs       si_wbr_mfs;
 123
 124         /* File-based Hierarchical Storage Management */
 125         struct au_fhsm          si_fhsm;
 126
 127         /* mount flags */
 128         /* include/asm-ia64/siginfo.h defines a macro named si_flags */
 129         unsigned int            si_mntflags;
 130
 131         /* external inode number (bitmap and translation table) */
 132         vfs_readf_t             si_xread;
 133         vfs_writef_t            si_xwrite;
 134         struct file             *si_xib;
 135         struct mutex            si_xib_mtx; /* protect xib members */
 136         unsigned long           *si_xib_buf;
 137         unsigned long           si_xib_last_pindex;
 138         int                     si_xib_next_bit;
 139         aufs_bindex_t           si_xino_brid;
 140         unsigned long           si_xino_jiffy;
 141         unsigned long           si_xino_expire;
 142         /* reserved for future use */
 143         /* unsigned long long   si_xib_limit; */        /* Max xib file size */
 144
 145 #ifdef CONFIG_AUFS_EXPORT
 146         /* i_generation */
 147         struct file             *si_xigen;
 148         atomic_t                si_xigen_next;
 149 #endif
 150
 151         /* dirty trick to suppoer atomic_open */
 152         struct au_sphlhead      si_aopen;
 153
 154         /* vdir parameters */
 155         unsigned long           si_rdcache;     /* max cache time in jiffies */
 156         unsigned int            si_rdblk;       /* deblk size */
 157         unsigned int            si_rdhash;      /* hash size */
 158
 159         /*
 160          * If the number of whiteouts are larger than si_dirwh, leave all of
 161          * them after au_whtmp_ren to reduce the cost of rmdir(2).
 162          * future fsck.aufs or kernel thread will remove them later.
 163          * Otherwise, remove all whiteouts and the dir in rmdir(2).
 164          */
 165         unsigned int            si_dirwh;
 166
 167         /* pseudo_link list */
 168         struct au_sphlhead      si_plink[AuPlink_NHASH];
 169         wait_queue_head_t       si_plink_wq;
 170         spinlock_t              si_plink_maint_lock;
 171         pid_t                   si_plink_maint_pid;
 172
 173         /* file list */
 174         struct au_sphlhead      si_files;
 175
 176         /* with/without getattr, brother of sb->s_d_op */
 177         struct inode_operations *si_iop_array;
 178
 179         /*
 180          * sysfs and lifetime management.
 181          * this is not a small structure and it may be a waste of memory in case
 182          * of sysfs is disabled, particulary when many aufs-es are mounted.
 183          * but using sysfs is majority.
 184          */
 185         struct kobject          si_kobj;
 186 #ifdef CONFIG_DEBUG_FS
 187         struct dentry            *si_dbgaufs;
 188         struct dentry            *si_dbgaufs_plink;
 189         struct dentry            *si_dbgaufs_xib;
 190 #ifdef CONFIG_AUFS_EXPORT
 191         struct dentry            *si_dbgaufs_xigen;
 192 #endif
 193 #endif
 194
 195 #ifdef CONFIG_AUFS_SBILIST
 196         struct hlist_node       si_list;
 197 #endif
 198
 199         /* dirty, necessary for unmounting, sysfs and sysrq */
 200         struct super_block      *si_sb;
 201 };
 202
 203 /* sbinfo status flags */
 204 /*
 205  * set true when refresh_dirs() failed at remount time.
 206  * then try refreshing dirs at access time again.
 207  * if it is false, refreshing dirs at access time is unnecesary
 208  */
 209 #define AuSi_FAILED_REFRESH_DIR 1
 210 #define AuSi_FHSM               (1 << 1)        /* fhsm is active now */
 211 #define AuSi_NO_DREVAL          (1 << 2)        /* disable all d_revalidate */
 212
 213 #ifndef CONFIG_AUFS_FHSM
 214 #undef AuSi_FHSM
 215 #define AuSi_FHSM               0
 216 #endif
 217
 218 static inline unsigned char au_do_ftest_si(struct au_sbinfo *sbi,
 219                                            unsigned int flag)
 220 {
 221         AuRwMustAnyLock(&sbi->si_rwsem);
 222         return sbi->au_si_status & flag;
 223 }
 224 #define au_ftest_si(sbinfo, name)       au_do_ftest_si(sbinfo, AuSi_##name)
 225 #define au_fset_si(sbinfo, name) do { \
 226         AuRwMustWriteLock(&(sbinfo)->si_rwsem); \
 227         (sbinfo)->au_si_status |= AuSi_##name; \
 228 } while (0)
 229 #define au_fclr_si(sbinfo, name) do { \
 230         AuRwMustWriteLock(&(sbinfo)->si_rwsem); \
 231         (sbinfo)->au_si_status &= ~AuSi_##name; \
 232 } while (0)
 233
 234 /* ---------------------------------------------------------------------- */
 235
 236 /* policy to select one among writable branches */
 237 #define AuWbrCopyup(sbinfo, ...) \
 238         ((sbinfo)->si_wbr_copyup_ops->copyup(__VA_ARGS__))
 239 #define AuWbrCreate(sbinfo, ...) \
 240         ((sbinfo)->si_wbr_create_ops->create(__VA_ARGS__))
 241
 242 /* flags for si_read_lock()/aufs_read_lock()/di_read_lock() */
 243 #define AuLock_DW               1               /* write-lock dentry */
 244 #define AuLock_IR               (1 << 1)        /* read-lock inode */
 245 #define AuLock_IW               (1 << 2)        /* write-lock inode */
 246 #define AuLock_FLUSH            (1 << 3)        /* wait for 'nowait' tasks */
 247 #define AuLock_DIRS             (1 << 4)        /* target is a pair of dirs */
 248                                                 /* except RENAME_EXCHANGE */
 249 #define AuLock_NOPLM            (1 << 5)        /* return err in plm mode */
 250 #define AuLock_NOPLMW           (1 << 6)        /* wait for plm mode ends */
 251 #define AuLock_GEN              (1 << 7)        /* test digen/iigen */
 252 #define au_ftest_lock(flags, name)      ((flags) & AuLock_##name)
 253 #define au_fset_lock(flags, name) \
 254         do { (flags) |= AuLock_##name; } while (0)
 255 #define au_fclr_lock(flags, name) \
 256         do { (flags) &= ~AuLock_##name; } while (0)
 257
 258 /* ---------------------------------------------------------------------- */
 259
 260 /* super.c */
 261 extern struct file_system_type aufs_fs_type;
 262 struct inode *au_iget_locked(struct super_block *sb, ino_t ino);
 263 typedef unsigned long long (*au_arraycb_t)(struct super_block *sb, void *array,
 264                                            unsigned long long max, void *arg);
 265 void *au_array_alloc(unsigned long long *hint, au_arraycb_t cb,
 266                      struct super_block *sb, void *arg);
 267 struct inode **au_iarray_alloc(struct super_block *sb, unsigned long long *max);
 268 void au_iarray_free(struct inode **a, unsigned long long max);
 269
 270 /* sbinfo.c */
 271 void au_si_free(struct kobject *kobj);
 272 int au_si_alloc(struct super_block *sb);
 273 int au_sbr_realloc(struct au_sbinfo *sbinfo, int nbr, int may_shrink);
 274
 275 unsigned int au_sigen_inc(struct super_block *sb);
 276 aufs_bindex_t au_new_br_id(struct super_block *sb);
 277
 278 int si_read_lock(struct super_block *sb, int flags);
 279 int si_write_lock(struct super_block *sb, int flags);
 280 int aufs_read_lock(struct dentry *dentry, int flags);
 281 void aufs_read_unlock(struct dentry *dentry, int flags);
 282 void aufs_write_lock(struct dentry *dentry);
 283 void aufs_write_unlock(struct dentry *dentry);
 284 int aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int flags);
 285 void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2);
 286
 287 /* wbr_policy.c */
 288 extern struct au_wbr_copyup_operations au_wbr_copyup_ops[];
 289 extern struct au_wbr_create_operations au_wbr_create_ops[];
 290 int au_cpdown_dirs(struct dentry *dentry, aufs_bindex_t bdst);
 291 int au_wbr_nonopq(struct dentry *dentry, aufs_bindex_t bindex);
 292 int au_wbr_do_copyup_bu(struct dentry *dentry, aufs_bindex_t btop);
 293
 294 /* mvdown.c */
 295 int au_mvdown(struct dentry *dentry, struct aufs_mvdown __user *arg);
 296
 297 #ifdef CONFIG_AUFS_FHSM
 298 /* fhsm.c */
 299
 300 static inline pid_t au_fhsm_pid(struct au_fhsm *fhsm)
 301 {
 302         pid_t pid;
 303
 304         spin_lock(&fhsm->fhsm_spin);
 305         pid = fhsm->fhsm_pid;
 306         spin_unlock(&fhsm->fhsm_spin);
 307
 308         return pid;
 309 }
 310
 311 void au_fhsm_wrote(struct super_block *sb, aufs_bindex_t bindex, int force);
 312 void au_fhsm_wrote_all(struct super_block *sb, int force);
 313 int au_fhsm_fd(struct super_block *sb, int oflags);
 314 int au_fhsm_br_alloc(struct au_branch *br);
 315 void au_fhsm_set_bottom(struct super_block *sb, aufs_bindex_t bindex);
 316 void au_fhsm_fin(struct super_block *sb);
 317 void au_fhsm_init(struct au_sbinfo *sbinfo);
 318 void au_fhsm_set(struct au_sbinfo *sbinfo, unsigned int sec);
 319 void au_fhsm_show(struct seq_file *seq, struct au_sbinfo *sbinfo);
 320 #else
 321 AuStubVoid(au_fhsm_wrote, struct super_block *sb, aufs_bindex_t bindex,
 322            int force)
 323 AuStubVoid(au_fhsm_wrote_all, struct super_block *sb, int force)
 324 AuStub(int, au_fhsm_fd, return -EOPNOTSUPP, struct super_block *sb, int oflags)
 325 AuStub(pid_t, au_fhsm_pid, return 0, struct au_fhsm *fhsm)
 326 AuStubInt0(au_fhsm_br_alloc, struct au_branch *br)
 327 AuStubVoid(au_fhsm_set_bottom, struct super_block *sb, aufs_bindex_t bindex)
 328 AuStubVoid(au_fhsm_fin, struct super_block *sb)
 329 AuStubVoid(au_fhsm_init, struct au_sbinfo *sbinfo)
 330 AuStubVoid(au_fhsm_set, struct au_sbinfo *sbinfo, unsigned int sec)
 331 AuStubVoid(au_fhsm_show, struct seq_file *seq, struct au_sbinfo *sbinfo)
 332 #endif
 333
 334 /* ---------------------------------------------------------------------- */
 335
 336 static inline struct au_sbinfo *au_sbi(struct super_block *sb)
 337 {
 338         return sb->s_fs_info;
 339 }
 340
 341 /* ---------------------------------------------------------------------- */
 342
 343 #ifdef CONFIG_AUFS_EXPORT
 344 int au_test_nfsd(void);
 345 void au_export_init(struct super_block *sb);
 346 void au_xigen_inc(struct inode *inode);
 347 int au_xigen_new(struct inode *inode);
 348 int au_xigen_set(struct super_block *sb, struct file *base);
 349 void au_xigen_clr(struct super_block *sb);
 350
 351 static inline int au_busy_or_stale(void)
 352 {
 353         if (!au_test_nfsd())
 354                 return -EBUSY;
 355         return -ESTALE;
 356 }
 357 #else
 358 AuStubInt0(au_test_nfsd, void)
 359 AuStubVoid(au_export_init, struct super_block *sb)
 360 AuStubVoid(au_xigen_inc, struct inode *inode)
 361 AuStubInt0(au_xigen_new, struct inode *inode)
 362 AuStubInt0(au_xigen_set, struct super_block *sb, struct file *base)
 363 AuStubVoid(au_xigen_clr, struct super_block *sb)
 364 AuStub(int, au_busy_or_stale, return -EBUSY, void)
 365 #endif /* CONFIG_AUFS_EXPORT */
 366
 367 /* ---------------------------------------------------------------------- */
 368
 369 #ifdef CONFIG_AUFS_SBILIST
 370 /* module.c */
 371 extern struct au_sphlhead au_sbilist;
 372
 373 static inline void au_sbilist_init(void)
 374 {
 375         au_sphl_init(&au_sbilist);
 376 }
 377
 378 static inline void au_sbilist_add(struct super_block *sb)
 379 {
 380         au_sphl_add(&au_sbi(sb)->si_list, &au_sbilist);
 381 }
 382
 383 static inline void au_sbilist_del(struct super_block *sb)
 384 {
 385         au_sphl_del(&au_sbi(sb)->si_list, &au_sbilist);
 386 }
 387
 388 #ifdef CONFIG_AUFS_MAGIC_SYSRQ
 389 static inline void au_sbilist_lock(void)
 390 {
 391         spin_lock(&au_sbilist.spin);
 392 }
 393
 394 static inline void au_sbilist_unlock(void)
 395 {
 396         spin_unlock(&au_sbilist.spin);
 397 }
 398 #define AuGFP_SBILIST   GFP_ATOMIC
 399 #else
 400 AuStubVoid(au_sbilist_lock, void)
 401 AuStubVoid(au_sbilist_unlock, void)
 402 #define AuGFP_SBILIST   GFP_NOFS
 403 #endif /* CONFIG_AUFS_MAGIC_SYSRQ */
 404 #else
 405 AuStubVoid(au_sbilist_init, void)
 406 AuStubVoid(au_sbilist_add, struct super_block *sb)
 407 AuStubVoid(au_sbilist_del, struct super_block *sb)
 408 AuStubVoid(au_sbilist_lock, void)
 409 AuStubVoid(au_sbilist_unlock, void)
 410 #define AuGFP_SBILIST   GFP_NOFS
 411 #endif
 412
 413 /* ---------------------------------------------------------------------- */
 414
 415 static inline void dbgaufs_si_null(struct au_sbinfo *sbinfo)
 416 {
 417         /*
 418          * This function is a dynamic '__init' function actually,
 419          * so the tiny check for si_rwsem is unnecessary.
 420          */
 421         /* AuRwMustWriteLock(&sbinfo->si_rwsem); */
 422 #ifdef CONFIG_DEBUG_FS
 423         sbinfo->si_dbgaufs = NULL;
 424         sbinfo->si_dbgaufs_plink = NULL;
 425         sbinfo->si_dbgaufs_xib = NULL;
 426 #ifdef CONFIG_AUFS_EXPORT
 427         sbinfo->si_dbgaufs_xigen = NULL;
 428 #endif
 429 #endif
 430 }
 431
 432 /* ---------------------------------------------------------------------- */
 433
 434 /* current->atomic_flags */
 435 /* this value should never corrupt the ones defined in linux/sched.h */
 436 #define PFA_AUFS        7
 437
 438 TASK_PFA_TEST(AUFS, test_aufs)  /* task_test_aufs */
 439 TASK_PFA_SET(AUFS, aufs)        /* task_set_aufs */
 440 TASK_PFA_CLEAR(AUFS, aufs)      /* task_clear_aufs */
 441
 442 static inline int si_pid_test(struct super_block *sb)
 443 {
 444         return !!task_test_aufs(current);
 445 }
 446
 447 static inline void si_pid_clr(struct super_block *sb)
 448 {
 449         AuDebugOn(!task_test_aufs(current));
 450         task_clear_aufs(current);
 451 }
 452
 453 static inline void si_pid_set(struct super_block *sb)
 454 {
 455         AuDebugOn(task_test_aufs(current));
 456         task_set_aufs(current);
 457 }
 458
 459 /* ---------------------------------------------------------------------- */
 460
 461 /* lock superblock. mainly for entry point functions */
 462 /*
 463  * __si_read_lock, __si_write_lock,
 464  * __si_read_unlock, __si_write_unlock, __si_downgrade_lock
 465  */
 466 AuSimpleRwsemFuncs(__si, struct super_block *sb, &au_sbi(sb)->si_rwsem);
 467
 468 #define SiMustNoWaiters(sb)     AuRwMustNoWaiters(&au_sbi(sb)->si_rwsem)
 469 #define SiMustAnyLock(sb)       AuRwMustAnyLock(&au_sbi(sb)->si_rwsem)
 470 #define SiMustWriteLock(sb)     AuRwMustWriteLock(&au_sbi(sb)->si_rwsem)
 471
 472 static inline void si_noflush_read_lock(struct super_block *sb)
 473 {
 474         __si_read_lock(sb);
 475         si_pid_set(sb);
 476 }
 477
 478 static inline int si_noflush_read_trylock(struct super_block *sb)
 479 {
 480         int locked;
 481
 482         locked = __si_read_trylock(sb);
 483         if (locked)
 484                 si_pid_set(sb);
 485         return locked;
 486 }
 487
 488 static inline void si_noflush_write_lock(struct super_block *sb)
 489 {
 490         __si_write_lock(sb);
 491         si_pid_set(sb);
 492 }
 493
 494 static inline int si_noflush_write_trylock(struct super_block *sb)
 495 {
 496         int locked;
 497
 498         locked = __si_write_trylock(sb);
 499         if (locked)
 500                 si_pid_set(sb);
 501         return locked;
 502 }
 503
 504 #if 0 /* reserved */
 505 static inline int si_read_trylock(struct super_block *sb, int flags)
 506 {
 507         if (au_ftest_lock(flags, FLUSH))
 508                 au_nwt_flush(&au_sbi(sb)->si_nowait);
 509         return si_noflush_read_trylock(sb);
 510 }
 511 #endif
 512
 513 static inline void si_read_unlock(struct super_block *sb)
 514 {
 515         si_pid_clr(sb);
 516         __si_read_unlock(sb);
 517 }
 518
 519 #if 0 /* reserved */
 520 static inline int si_write_trylock(struct super_block *sb, int flags)
 521 {
 522         if (au_ftest_lock(flags, FLUSH))
 523                 au_nwt_flush(&au_sbi(sb)->si_nowait);
 524         return si_noflush_write_trylock(sb);
 525 }
 526 #endif
 527
 528 static inline void si_write_unlock(struct super_block *sb)
 529 {
 530         si_pid_clr(sb);
 531         __si_write_unlock(sb);
 532 }
 533
 534 #if 0 /* reserved */
 535 static inline void si_downgrade_lock(struct super_block *sb)
 536 {
 537         __si_downgrade_lock(sb);
 538 }
 539 #endif
 540
 541 /* ---------------------------------------------------------------------- */
 542
 543 static inline aufs_bindex_t au_sbbot(struct super_block *sb)
 544 {
 545         SiMustAnyLock(sb);
 546         return au_sbi(sb)->si_bbot;
 547 }
 548
 549 static inline unsigned int au_mntflags(struct super_block *sb)
 550 {
 551         SiMustAnyLock(sb);
 552         return au_sbi(sb)->si_mntflags;
 553 }
 554
 555 static inline unsigned int au_sigen(struct super_block *sb)
 556 {
 557         SiMustAnyLock(sb);
 558         return au_sbi(sb)->si_generation;
 559 }
 560
 561 static inline unsigned long long au_ninodes(struct super_block *sb)
 562 {
 563         s64 n = percpu_counter_sum(&au_sbi(sb)->si_ninodes);
 564
 565         BUG_ON(n < 0);
 566         return n;
 567 }
 568
 569 static inline void au_ninodes_inc(struct super_block *sb)
 570 {
 571         percpu_counter_inc(&au_sbi(sb)->si_ninodes);
 572 }
 573
 574 static inline void au_ninodes_dec(struct super_block *sb)
 575 {
 576         percpu_counter_dec(&au_sbi(sb)->si_ninodes);
 577 }
 578
 579 static inline unsigned long long au_nfiles(struct super_block *sb)
 580 {
 581         s64 n = percpu_counter_sum(&au_sbi(sb)->si_nfiles);
 582
 583         BUG_ON(n < 0);
 584         return n;
 585 }
 586
 587 static inline void au_nfiles_inc(struct super_block *sb)
 588 {
 589         percpu_counter_inc(&au_sbi(sb)->si_nfiles);
 590 }
 591
 592 static inline void au_nfiles_dec(struct super_block *sb)
 593 {
 594         percpu_counter_dec(&au_sbi(sb)->si_nfiles);
 595 }
 596
 597 static inline struct au_branch *au_sbr(struct super_block *sb,
 598                                        aufs_bindex_t bindex)
 599 {
 600         SiMustAnyLock(sb);
 601         return au_sbi(sb)->si_branch[0 + bindex];
 602 }
 603
 604 static inline void au_xino_brid_set(struct super_block *sb, aufs_bindex_t brid)
 605 {
 606         SiMustWriteLock(sb);
 607         au_sbi(sb)->si_xino_brid = brid;
 608 }
 609
 610 static inline aufs_bindex_t au_xino_brid(struct super_block *sb)
 611 {
 612         SiMustAnyLock(sb);
 613         return au_sbi(sb)->si_xino_brid;
 614 }
 615
 616 #endif /* __KERNEL__ */
 617 #endif /* __AUFS_SUPER_H__ */