include/linux/nfs_fs.h

   1 /*
   2  *  linux/include/linux/nfs_fs.h
   3  *
   4  *  Copyright (C) 1992  Rick Sladkey
   5  *
   6  *  OS-specific nfs filesystem definitions and declarations
   7  */
   8
   9 #ifndef _LINUX_NFS_FS_H
  10 #define _LINUX_NFS_FS_H
  11
  12 #include <linux/magic.h>
  13
  14 /* Default timeout values */
  15 #define NFS_DEF_UDP_TIMEO       (11)
  16 #define NFS_DEF_UDP_RETRANS     (3)
  17 #define NFS_DEF_TCP_TIMEO       (600)
  18 #define NFS_DEF_TCP_RETRANS     (2)
  19
  20 #define NFS_MAX_UDP_TIMEOUT     (60*HZ)
  21 #define NFS_MAX_TCP_TIMEOUT     (600*HZ)
  22
  23 #define NFS_DEF_ACREGMIN        (3)
  24 #define NFS_DEF_ACREGMAX        (60)
  25 #define NFS_DEF_ACDIRMIN        (30)
  26 #define NFS_DEF_ACDIRMAX        (60)
  27
  28 /*
  29  * When flushing a cluster of dirty pages, there can be different
  30  * strategies:
  31  */
  32 #define FLUSH_SYNC              1       /* file being synced, or contention */
  33 #define FLUSH_STABLE            4       /* commit to stable storage */
  34 #define FLUSH_LOWPRI            8       /* low priority background flush */
  35 #define FLUSH_HIGHPRI           16      /* high priority memory reclaim flush */
  36 #define FLUSH_NOCOMMIT          32      /* Don't send the NFSv3/v4 COMMIT */
  37 #define FLUSH_INVALIDATE        64      /* Invalidate the page cache */
  38 #define FLUSH_NOWRITEPAGE       128     /* Don't call writepage() */
  39
  40 #ifdef __KERNEL__
  41
  42 #include <linux/in.h>
  43 #include <linux/mm.h>
  44 #include <linux/pagemap.h>
  45 #include <linux/rbtree.h>
  46 #include <linux/rwsem.h>
  47 #include <linux/wait.h>
  48
  49 #include <linux/sunrpc/debug.h>
  50 #include <linux/sunrpc/auth.h>
  51 #include <linux/sunrpc/clnt.h>
  52
  53 #include <linux/nfs.h>
  54 #include <linux/nfs2.h>
  55 #include <linux/nfs3.h>
  56 #include <linux/nfs4.h>
  57 #include <linux/nfs_xdr.h>
  58 #include <linux/nfs_fs_sb.h>
  59
  60 #include <linux/mempool.h>
  61
  62 /*
  63  * These are the default flags for swap requests
  64  */
  65 #define NFS_RPC_SWAPFLAGS               (RPC_TASK_SWAPPER|RPC_TASK_ROOTCREDS)
  66
  67 /*
  68  * NFSv3/v4 Access mode cache entry
  69  */
  70 struct nfs_access_entry {
  71         struct rb_node          rb_node;
  72         struct list_head        lru;
  73         unsigned long           jiffies;
  74         struct rpc_cred *       cred;
  75         int                     mask;
  76 };
  77
  78 struct nfs4_state;
  79 struct nfs_open_context {
  80         atomic_t count;
  81         struct path path;
  82         struct rpc_cred *cred;
  83         struct nfs4_state *state;
  84         fl_owner_t lockowner;
  85         fmode_t mode;
  86
  87         unsigned long flags;
  88 #define NFS_CONTEXT_ERROR_WRITE         (0)
  89         int error;
  90
  91         struct list_head list;
  92
  93         __u64 dir_cookie;
  94 };
  95
  96 /*
  97  * NFSv4 delegation
  98  */
  99 struct nfs_delegation;
 100
 101 struct posix_acl;
 102
 103 /*
 104  * nfs fs inode data in memory
 105  */
 106 struct nfs_inode {
 107         /*
 108          * The 64bit 'inode number'
 109          */
 110         __u64 fileid;
 111
 112         /*
 113          * NFS file handle
 114          */
 115         struct nfs_fh           fh;
 116
 117         /*
 118          * Various flags
 119          */
 120         unsigned long           flags;                  /* atomic bit ops */
 121         unsigned long           cache_validity;         /* bit mask */
 122
 123         /*
 124          * read_cache_jiffies is when we started read-caching this inode.
 125          * attrtimeo is for how long the cached information is assumed
 126          * to be valid. A successful attribute revalidation doubles
 127          * attrtimeo (up to acregmax/acdirmax), a failure resets it to
 128          * acregmin/acdirmin.
 129          *
 130          * We need to revalidate the cached attrs for this inode if
 131          *
 132          *      jiffies - read_cache_jiffies >= attrtimeo
 133          *
 134          * Please note the comparison is greater than or equal
 135          * so that zero timeout values can be specified.
 136          */
 137         unsigned long           read_cache_jiffies;
 138         unsigned long           attrtimeo;
 139         unsigned long           attrtimeo_timestamp;
 140         __u64                   change_attr;            /* v4 only */
 141
 142         unsigned long           attr_gencount;
 143         /* "Generation counter" for the attribute cache. This is
 144          * bumped whenever we update the metadata on the
 145          * server.
 146          */
 147         unsigned long           cache_change_attribute;
 148
 149         struct rb_root          access_cache;
 150         struct list_head        access_cache_entry_lru;
 151         struct list_head        access_cache_inode_lru;
 152 #ifdef CONFIG_NFS_V3_ACL
 153         struct posix_acl        *acl_access;
 154         struct posix_acl        *acl_default;
 155 #endif
 156
 157         /*
 158          * This is the cookie verifier used for NFSv3 readdir
 159          * operations
 160          */
 161         __be32                  cookieverf[2];
 162
 163         /*
 164          * This is the list of dirty unwritten pages.
 165          */
 166         struct radix_tree_root  nfs_page_tree;
 167
 168         unsigned long           npages;
 169
 170         /* Open contexts for shared mmap writes */
 171         struct list_head        open_files;
 172
 173         /* Number of in-flight sillydelete RPC calls */
 174         atomic_t                silly_count;
 175         /* List of deferred sillydelete requests */
 176         struct hlist_head       silly_list;
 177         wait_queue_head_t       waitqueue;
 178
 179 #ifdef CONFIG_NFS_V4
 180         struct nfs4_cached_acl  *nfs4_acl;
 181         /* NFSv4 state */
 182         struct list_head        open_states;
 183         struct nfs_delegation   *delegation;
 184         fmode_t                  delegation_state;
 185         struct rw_semaphore     rwsem;
 186 #endif /* CONFIG_NFS_V4*/
 187 #ifdef CONFIG_NFS_FSCACHE
 188         struct fscache_cookie   *fscache;
 189 #endif
 190         struct inode            vfs_inode;
 191 };
 192
 193 /*
 194  * Cache validity bit flags
 195  */
 196 #define NFS_INO_INVALID_ATTR    0x0001          /* cached attrs are invalid */
 197 #define NFS_INO_INVALID_DATA    0x0002          /* cached data is invalid */
 198 #define NFS_INO_INVALID_ATIME   0x0004          /* cached atime is invalid */
 199 #define NFS_INO_INVALID_ACCESS  0x0008          /* cached access cred invalid */
 200 #define NFS_INO_INVALID_ACL     0x0010          /* cached acls are invalid */
 201 #define NFS_INO_REVAL_PAGECACHE 0x0020          /* must revalidate pagecache */
 202 #define NFS_INO_REVAL_FORCED    0x0040          /* force revalidation ignoring a delegation */
 203
 204 /*
 205  * Bit offsets in flags field
 206  */
 207 #define NFS_INO_ADVISE_RDPLUS   (0)             /* advise readdirplus */
 208 #define NFS_INO_STALE           (1)             /* possible stale inode */
 209 #define NFS_INO_ACL_LRU_SET     (2)             /* Inode is on the LRU list */
 210 #define NFS_INO_MOUNTPOINT      (3)             /* inode is remote mountpoint */
 211 #define NFS_INO_FLUSHING        (4)             /* inode is flushing out data */
 212 #define NFS_INO_FSCACHE         (5)             /* inode can be cached by FS-Cache */
 213 #define NFS_INO_FSCACHE_LOCK    (6)             /* FS-Cache cookie management lock */
 214
 215 static inline struct nfs_inode *NFS_I(const struct inode *inode)
 216 {
 217         return container_of(inode, struct nfs_inode, vfs_inode);
 218 }
 219
 220 static inline struct nfs_server *NFS_SB(const struct super_block *s)
 221 {
 222         return (struct nfs_server *)(s->s_fs_info);
 223 }
 224
 225 static inline struct nfs_fh *NFS_FH(const struct inode *inode)
 226 {
 227         return &NFS_I(inode)->fh;
 228 }
 229
 230 static inline struct nfs_server *NFS_SERVER(const struct inode *inode)
 231 {
 232         return NFS_SB(inode->i_sb);
 233 }
 234
 235 static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode)
 236 {
 237         return NFS_SERVER(inode)->client;
 238 }
 239
 240 static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode)
 241 {
 242         return NFS_SERVER(inode)->nfs_client->rpc_ops;
 243 }
 244
 245 static inline __be32 *NFS_COOKIEVERF(const struct inode *inode)
 246 {
 247         return NFS_I(inode)->cookieverf;
 248 }
 249
 250 static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode)
 251 {
 252         struct nfs_server *nfss = NFS_SERVER(inode);
 253         return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin;
 254 }
 255
 256 static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode)
 257 {
 258         struct nfs_server *nfss = NFS_SERVER(inode);
 259         return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax;
 260 }
 261
 262 static inline int NFS_STALE(const struct inode *inode)
 263 {
 264         return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
 265 }
 266
 267 static inline int NFS_FSCACHE(const struct inode *inode)
 268 {
 269         return test_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags);
 270 }
 271
 272 static inline __u64 NFS_FILEID(const struct inode *inode)
 273 {
 274         return NFS_I(inode)->fileid;
 275 }
 276
 277 static inline void set_nfs_fileid(struct inode *inode, __u64 fileid)
 278 {
 279         NFS_I(inode)->fileid = fileid;
 280 }
 281
 282 static inline void nfs_mark_for_revalidate(struct inode *inode)
 283 {
 284         struct nfs_inode *nfsi = NFS_I(inode);
 285
 286         spin_lock(&inode->i_lock);
 287         nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS;
 288         if (S_ISDIR(inode->i_mode))
 289                 nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_DATA;
 290         spin_unlock(&inode->i_lock);
 291 }
 292
 293 static inline int nfs_server_capable(struct inode *inode, int cap)
 294 {
 295         return NFS_SERVER(inode)->caps & cap;
 296 }
 297
 298 static inline int NFS_USE_READDIRPLUS(struct inode *inode)
 299 {
 300         return test_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
 301 }
 302
 303 static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
 304 {
 305         dentry->d_time = verf;
 306 }
 307
 308 /**
 309  * nfs_save_change_attribute - Returns the inode attribute change cookie
 310  * @dir - pointer to parent directory inode
 311  * The "change attribute" is updated every time we finish an operation
 312  * that will result in a metadata change on the server.
 313  */
 314 static inline unsigned long nfs_save_change_attribute(struct inode *dir)
 315 {
 316         return NFS_I(dir)->cache_change_attribute;
 317 }
 318
 319 /**
 320  * nfs_verify_change_attribute - Detects NFS remote directory changes
 321  * @dir - pointer to parent directory inode
 322  * @chattr - previously saved change attribute
 323  * Return "false" if the verifiers doesn't match the change attribute.
 324  * This would usually indicate that the directory contents have changed on
 325  * the server, and that any dentries need revalidating.
 326  */
 327 static inline int nfs_verify_change_attribute(struct inode *dir, unsigned long chattr)
 328 {
 329         return chattr == NFS_I(dir)->cache_change_attribute;
 330 }
 331
 332 /*
 333  * linux/fs/nfs/inode.c
 334  */
 335 extern int nfs_sync_mapping(struct address_space *mapping);
 336 extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping);
 337 extern void nfs_zap_caches(struct inode *);
 338 extern void nfs_invalidate_atime(struct inode *);
 339 extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
 340                                 struct nfs_fattr *);
 341 extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
 342 extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
 343 extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
 344 extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
 345 extern int nfs_permission(struct inode *, int);
 346 extern int nfs_open(struct inode *, struct file *);
 347 extern int nfs_release(struct inode *, struct file *);
 348 extern int nfs_attribute_timeout(struct inode *inode);
 349 extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode);
 350 extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
 351 extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
 352 extern int nfs_revalidate_mapping_nolock(struct inode *inode, struct address_space *mapping);
 353 extern int nfs_setattr(struct dentry *, struct iattr *);
 354 extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr);
 355 extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
 356 extern void put_nfs_open_context(struct nfs_open_context *ctx);
 357 extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode);
 358 extern u64 nfs_compat_user_ino64(u64 fileid);
 359 extern void nfs_fattr_init(struct nfs_fattr *fattr);
 360
 361 /* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
 362 extern __be32 root_nfs_parse_addr(char *name); /*__init*/
 363 extern unsigned long nfs_inc_attr_generation_counter(void);
 364
 365 /*
 366  * linux/fs/nfs/file.c
 367  */
 368 extern const struct inode_operations nfs_file_inode_operations;
 369 #ifdef CONFIG_NFS_V3
 370 extern const struct inode_operations nfs3_file_inode_operations;
 371 #endif /* CONFIG_NFS_V3 */
 372 extern const struct file_operations nfs_file_operations;
 373 extern const struct address_space_operations nfs_file_aops;
 374
 375 static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
 376 {
 377         return filp->private_data;
 378 }
 379
 380 static inline struct rpc_cred *nfs_file_cred(struct file *file)
 381 {
 382         if (file != NULL) {
 383                 struct nfs_open_context *ctx =
 384                         nfs_file_open_context(file);
 385                 if (ctx)
 386                         return ctx->cred;
 387         }
 388         return NULL;
 389 }
 390
 391 /*
 392  * linux/fs/nfs/xattr.c
 393  */
 394 #ifdef CONFIG_NFS_V3_ACL
 395 extern ssize_t nfs3_listxattr(struct dentry *, char *, size_t);
 396 extern ssize_t nfs3_getxattr(struct dentry *, const char *, void *, size_t);
 397 extern int nfs3_setxattr(struct dentry *, const char *,
 398                         const void *, size_t, int);
 399 extern int nfs3_removexattr (struct dentry *, const char *name);
 400 #else
 401 # define nfs3_listxattr NULL
 402 # define nfs3_getxattr NULL
 403 # define nfs3_setxattr NULL
 404 # define nfs3_removexattr NULL
 405 #endif
 406
 407 /*
 408  * linux/fs/nfs/direct.c
 409  */
 410 extern ssize_t nfs_direct_IO(int, struct kiocb *, const struct iovec *, loff_t,
 411                         unsigned long);
 412 extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
 413                         const struct iovec *iov, unsigned long nr_segs,
 414                         loff_t pos);
 415 extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
 416                         const struct iovec *iov, unsigned long nr_segs,
 417                         loff_t pos);
 418
 419 /*
 420  * linux/fs/nfs/dir.c
 421  */
 422 extern const struct inode_operations nfs_dir_inode_operations;
 423 #ifdef CONFIG_NFS_V3
 424 extern const struct inode_operations nfs3_dir_inode_operations;
 425 #endif /* CONFIG_NFS_V3 */
 426 extern const struct file_operations nfs_dir_operations;
 427 extern const struct dentry_operations nfs_dentry_operations;
 428
 429 extern void nfs_force_lookup_revalidate(struct inode *dir);
 430 extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh, struct nfs_fattr *fattr);
 431 extern int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags);
 432 extern void nfs_access_zap_cache(struct inode *inode);
 433
 434 /*
 435  * linux/fs/nfs/symlink.c
 436  */
 437 extern const struct inode_operations nfs_symlink_inode_operations;
 438
 439 /*
 440  * linux/fs/nfs/sysctl.c
 441  */
 442 #ifdef CONFIG_SYSCTL
 443 extern int nfs_register_sysctl(void);
 444 extern void nfs_unregister_sysctl(void);
 445 #else
 446 #define nfs_register_sysctl() 0
 447 #define nfs_unregister_sysctl() do { } while(0)
 448 #endif
 449
 450 /*
 451  * linux/fs/nfs/namespace.c
 452  */
 453 extern const struct inode_operations nfs_mountpoint_inode_operations;
 454 extern const struct inode_operations nfs_referral_inode_operations;
 455 extern int nfs_mountpoint_expiry_timeout;
 456 extern void nfs_release_automount_timer(void);
 457
 458 /*
 459  * linux/fs/nfs/unlink.c
 460  */
 461 extern int  nfs_async_unlink(struct inode *dir, struct dentry *dentry);
 462 extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);
 463 extern void nfs_block_sillyrename(struct dentry *dentry);
 464 extern void nfs_unblock_sillyrename(struct dentry *dentry);
 465
 466 /*
 467  * linux/fs/nfs/write.c
 468  */
 469 extern int  nfs_congestion_kb;
 470 extern int  nfs_writepage(struct page *page, struct writeback_control *wbc);
 471 extern int  nfs_writepages(struct address_space *, struct writeback_control *);
 472 extern int  nfs_flush_incompatible(struct file *file, struct page *page);
 473 extern int  nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
 474 extern int nfs_writeback_done(struct rpc_task *, struct nfs_write_data *);
 475
 476 /*
 477  * Try to write back everything synchronously (but check the
 478  * return value!)
 479  */
 480 extern long nfs_sync_mapping_wait(struct address_space *, struct writeback_control *, int);
 481 extern int nfs_wb_all(struct inode *inode);
 482 extern int nfs_wb_nocommit(struct inode *inode);
 483 extern int nfs_wb_page(struct inode *inode, struct page* page);
 484 extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);
 485 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
 486 extern int  nfs_commit_inode(struct inode *, int);
 487 extern struct nfs_write_data *nfs_commitdata_alloc(void);
 488 extern void nfs_commit_free(struct nfs_write_data *wdata);
 489 #else
 490 static inline int
 491 nfs_commit_inode(struct inode *inode, int how)
 492 {
 493         return 0;
 494 }
 495 #endif
 496
 497 static inline int
 498 nfs_have_writebacks(struct inode *inode)
 499 {
 500         return NFS_I(inode)->npages != 0;
 501 }
 502
 503 /*
 504  * Allocate nfs_write_data structures
 505  */
 506 extern struct nfs_write_data *nfs_writedata_alloc(unsigned int npages);
 507 extern void nfs_writedata_free(struct nfs_write_data *);
 508
 509 /*
 510  * linux/fs/nfs/read.c
 511  */
 512 extern int  nfs_readpage(struct file *, struct page *);
 513 extern int  nfs_readpages(struct file *, struct address_space *,
 514                 struct list_head *, unsigned);
 515 extern int  nfs_readpage_result(struct rpc_task *, struct nfs_read_data *);
 516 extern int  nfs_readpage_async(struct nfs_open_context *, struct inode *,
 517                                struct page *);
 518
 519 /*
 520  * Allocate nfs_read_data structures
 521  */
 522 extern struct nfs_read_data *nfs_readdata_alloc(unsigned int npages);
 523 extern void nfs_readdata_free(struct nfs_read_data *);
 524
 525 /*
 526  * linux/fs/nfs3proc.c
 527  */
 528 #ifdef CONFIG_NFS_V3_ACL
 529 extern struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type);
 530 extern int nfs3_proc_setacl(struct inode *inode, int type,
 531                             struct posix_acl *acl);
 532 extern int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
 533                 mode_t mode);
 534 extern void nfs3_forget_cached_acls(struct inode *inode);
 535 #else
 536 static inline int nfs3_proc_set_default_acl(struct inode *dir,
 537                                             struct inode *inode,
 538                                             mode_t mode)
 539 {
 540         return 0;
 541 }
 542
 543 static inline void nfs3_forget_cached_acls(struct inode *inode)
 544 {
 545 }
 546 #endif /* CONFIG_NFS_V3_ACL */
 547
 548 /*
 549  * inline functions
 550  */
 551
 552 static inline loff_t nfs_size_to_loff_t(__u64 size)
 553 {
 554         if (size > (__u64) OFFSET_MAX - 1)
 555                 return OFFSET_MAX - 1;
 556         return (loff_t) size;
 557 }
 558
 559 static inline ino_t
 560 nfs_fileid_to_ino_t(u64 fileid)
 561 {
 562         ino_t ino = (ino_t) fileid;
 563         if (sizeof(ino_t) < sizeof(u64))
 564                 ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;
 565         return ino;
 566 }
 567
 568 /* NFS root */
 569
 570 extern void * nfs_root_data(void);
 571
 572 #define nfs_wait_event(clnt, wq, condition)                             \
 573 ({                                                                      \
 574         int __retval = wait_event_killable(wq, condition);              \
 575         __retval;                                                       \
 576 })
 577
 578 #define NFS_JUKEBOX_RETRY_TIME (5 * HZ)
 579
 580 #endif /* __KERNEL__ */
 581
 582 /*
 583  * NFS debug flags
 584  */
 585 #define NFSDBG_VFS              0x0001
 586 #define NFSDBG_DIRCACHE         0x0002
 587 #define NFSDBG_LOOKUPCACHE      0x0004
 588 #define NFSDBG_PAGECACHE        0x0008
 589 #define NFSDBG_PROC             0x0010
 590 #define NFSDBG_XDR              0x0020
 591 #define NFSDBG_FILE             0x0040
 592 #define NFSDBG_ROOT             0x0080
 593 #define NFSDBG_CALLBACK         0x0100
 594 #define NFSDBG_CLIENT           0x0200
 595 #define NFSDBG_MOUNT            0x0400
 596 #define NFSDBG_FSCACHE          0x0800
 597 #define NFSDBG_ALL              0xFFFF
 598
 599 #ifdef __KERNEL__
 600
 601 /*
 602  * Enable debugging support for nfs client.
 603  * Requires RPC_DEBUG.
 604  */
 605 #ifdef RPC_DEBUG
 606 # define NFS_DEBUG
 607 #endif
 608
 609 # undef ifdebug
 610 # ifdef NFS_DEBUG
 611 #  define ifdebug(fac)          if (unlikely(nfs_debug & NFSDBG_##fac))
 612 # else
 613 #  define ifdebug(fac)          if (0)
 614 # endif
 615 #endif /* __KERNEL */
 616
 617 #endif