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_COND_STABLE 32 /* conditional stable write - only stable 37 * if everything fits in one RPC */ 38 39 #ifdef __KERNEL__ 40 41 /* 42 * Enable dprintk() debugging support for nfs client. 43 */ 44 #ifdef CONFIG_NFS_DEBUG 45 # define NFS_DEBUG 46 #endif 47 48 #include <linux/in.h> 49 #include <linux/mm.h> 50 #include <linux/pagemap.h> 51 #include <linux/rbtree.h> 52 #include <linux/rwsem.h> 53 #include <linux/wait.h> 54 55 #include <linux/sunrpc/debug.h> 56 #include <linux/sunrpc/auth.h> 57 #include <linux/sunrpc/clnt.h> 58 59 #include <linux/nfs.h> 60 #include <linux/nfs2.h> 61 #include <linux/nfs3.h> 62 #include <linux/nfs4.h> 63 #include <linux/nfs_xdr.h> 64 #include <linux/nfs_fs_sb.h> 65 66 #include <linux/mempool.h> 67 68 /* 69 * These are the default flags for swap requests 70 */ 71 #define NFS_RPC_SWAPFLAGS (RPC_TASK_SWAPPER|RPC_TASK_ROOTCREDS) 72 73 /* 74 * NFSv3/v4 Access mode cache entry 75 */ 76 struct nfs_access_entry { 77 struct rb_node rb_node; 78 struct list_head lru; 79 unsigned long jiffies; 80 struct rpc_cred * cred; 81 int mask; 82 }; 83 84 struct nfs_lock_context { 85 atomic_t count; 86 struct list_head list; 87 struct nfs_open_context *open_context; 88 fl_owner_t lockowner; 89 pid_t pid; 90 }; 91 92 struct nfs4_state; 93 struct nfs_open_context { 94 struct nfs_lock_context lock_context; 95 struct dentry *dentry; 96 struct rpc_cred *cred; 97 struct nfs4_state *state; 98 fmode_t mode; 99 100 unsigned long flags; 101 #define NFS_CONTEXT_ERROR_WRITE (0) 102 int error; 103 104 struct list_head list; 105 struct nfs4_threshold *mdsthreshold; 106 }; 107 108 struct nfs_open_dir_context { 109 struct rpc_cred *cred; 110 unsigned long attr_gencount; 111 __u64 dir_cookie; 112 __u64 dup_cookie; 113 signed char duped; 114 }; 115 116 /* 117 * NFSv4 delegation 118 */ 119 struct nfs_delegation; 120 121 struct posix_acl; 122 123 /* 124 * nfs fs inode data in memory 125 */ 126 struct nfs_inode { 127 /* 128 * The 64bit 'inode number' 129 */ 130 __u64 fileid; 131 132 /* 133 * NFS file handle 134 */ 135 struct nfs_fh fh; 136 137 /* 138 * Various flags 139 */ 140 unsigned long flags; /* atomic bit ops */ 141 unsigned long cache_validity; /* bit mask */ 142 143 /* 144 * read_cache_jiffies is when we started read-caching this inode. 145 * attrtimeo is for how long the cached information is assumed 146 * to be valid. A successful attribute revalidation doubles 147 * attrtimeo (up to acregmax/acdirmax), a failure resets it to 148 * acregmin/acdirmin. 149 * 150 * We need to revalidate the cached attrs for this inode if 151 * 152 * jiffies - read_cache_jiffies >= attrtimeo 153 * 154 * Please note the comparison is greater than or equal 155 * so that zero timeout values can be specified. 156 */ 157 unsigned long read_cache_jiffies; 158 unsigned long attrtimeo; 159 unsigned long attrtimeo_timestamp; 160 161 unsigned long attr_gencount; 162 /* "Generation counter" for the attribute cache. This is 163 * bumped whenever we update the metadata on the 164 * server. 165 */ 166 unsigned long cache_change_attribute; 167 168 struct rb_root access_cache; 169 struct list_head access_cache_entry_lru; 170 struct list_head access_cache_inode_lru; 171 #ifdef CONFIG_NFS_V3_ACL 172 struct posix_acl *acl_access; 173 struct posix_acl *acl_default; 174 #endif 175 176 /* 177 * This is the cookie verifier used for NFSv3 readdir 178 * operations 179 */ 180 __be32 cookieverf[2]; 181 182 unsigned long npages; 183 struct nfs_mds_commit_info commit_info; 184 185 /* Open contexts for shared mmap writes */ 186 struct list_head open_files; 187 188 /* Number of in-flight sillydelete RPC calls */ 189 atomic_t silly_count; 190 /* List of deferred sillydelete requests */ 191 struct hlist_head silly_list; 192 wait_queue_head_t waitqueue; 193 194 #ifdef CONFIG_NFS_V4 195 struct nfs4_cached_acl *nfs4_acl; 196 /* NFSv4 state */ 197 struct list_head open_states; 198 struct nfs_delegation __rcu *delegation; 199 fmode_t delegation_state; 200 struct rw_semaphore rwsem; 201 202 /* pNFS layout information */ 203 struct pnfs_layout_hdr *layout; 204 #endif /* CONFIG_NFS_V4*/ 205 /* how many bytes have been written/read and how many bytes queued up */ 206 __u64 write_io; 207 __u64 read_io; 208 #ifdef CONFIG_NFS_FSCACHE 209 struct fscache_cookie *fscache; 210 #endif 211 struct inode vfs_inode; 212 }; 213 214 /* 215 * Cache validity bit flags 216 */ 217 #define NFS_INO_INVALID_ATTR 0x0001 /* cached attrs are invalid */ 218 #define NFS_INO_INVALID_DATA 0x0002 /* cached data is invalid */ 219 #define NFS_INO_INVALID_ATIME 0x0004 /* cached atime is invalid */ 220 #define NFS_INO_INVALID_ACCESS 0x0008 /* cached access cred invalid */ 221 #define NFS_INO_INVALID_ACL 0x0010 /* cached acls are invalid */ 222 #define NFS_INO_REVAL_PAGECACHE 0x0020 /* must revalidate pagecache */ 223 #define NFS_INO_REVAL_FORCED 0x0040 /* force revalidation ignoring a delegation */ 224 225 /* 226 * Bit offsets in flags field 227 */ 228 #define NFS_INO_ADVISE_RDPLUS (0) /* advise readdirplus */ 229 #define NFS_INO_STALE (1) /* possible stale inode */ 230 #define NFS_INO_ACL_LRU_SET (2) /* Inode is on the LRU list */ 231 #define NFS_INO_FLUSHING (4) /* inode is flushing out data */ 232 #define NFS_INO_FSCACHE (5) /* inode can be cached by FS-Cache */ 233 #define NFS_INO_FSCACHE_LOCK (6) /* FS-Cache cookie management lock */ 234 #define NFS_INO_COMMIT (7) /* inode is committing unstable writes */ 235 #define NFS_INO_LAYOUTCOMMIT (9) /* layoutcommit required */ 236 #define NFS_INO_LAYOUTCOMMITTING (10) /* layoutcommit inflight */ 237 238 static inline struct nfs_inode *NFS_I(const struct inode *inode) 239 { 240 return container_of(inode, struct nfs_inode, vfs_inode); 241 } 242 243 static inline struct nfs_server *NFS_SB(const struct super_block *s) 244 { 245 return (struct nfs_server *)(s->s_fs_info); 246 } 247 248 static inline struct nfs_fh *NFS_FH(const struct inode *inode) 249 { 250 return &NFS_I(inode)->fh; 251 } 252 253 static inline struct nfs_server *NFS_SERVER(const struct inode *inode) 254 { 255 return NFS_SB(inode->i_sb); 256 } 257 258 static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode) 259 { 260 return NFS_SERVER(inode)->client; 261 } 262 263 static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode) 264 { 265 return NFS_SERVER(inode)->nfs_client->rpc_ops; 266 } 267 268 static inline __be32 *NFS_COOKIEVERF(const struct inode *inode) 269 { 270 return NFS_I(inode)->cookieverf; 271 } 272 273 static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode) 274 { 275 struct nfs_server *nfss = NFS_SERVER(inode); 276 return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin; 277 } 278 279 static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode) 280 { 281 struct nfs_server *nfss = NFS_SERVER(inode); 282 return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax; 283 } 284 285 static inline int NFS_STALE(const struct inode *inode) 286 { 287 return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags); 288 } 289 290 static inline int NFS_FSCACHE(const struct inode *inode) 291 { 292 return test_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags); 293 } 294 295 static inline __u64 NFS_FILEID(const struct inode *inode) 296 { 297 return NFS_I(inode)->fileid; 298 } 299 300 static inline void set_nfs_fileid(struct inode *inode, __u64 fileid) 301 { 302 NFS_I(inode)->fileid = fileid; 303 } 304 305 static inline void nfs_mark_for_revalidate(struct inode *inode) 306 { 307 struct nfs_inode *nfsi = NFS_I(inode); 308 309 spin_lock(&inode->i_lock); 310 nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS; 311 if (S_ISDIR(inode->i_mode)) 312 nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_DATA; 313 spin_unlock(&inode->i_lock); 314 } 315 316 static inline int nfs_server_capable(struct inode *inode, int cap) 317 { 318 return NFS_SERVER(inode)->caps & cap; 319 } 320 321 static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf) 322 { 323 dentry->d_time = verf; 324 } 325 326 /** 327 * nfs_save_change_attribute - Returns the inode attribute change cookie 328 * @dir - pointer to parent directory inode 329 * The "change attribute" is updated every time we finish an operation 330 * that will result in a metadata change on the server. 331 */ 332 static inline unsigned long nfs_save_change_attribute(struct inode *dir) 333 { 334 return NFS_I(dir)->cache_change_attribute; 335 } 336 337 /** 338 * nfs_verify_change_attribute - Detects NFS remote directory changes 339 * @dir - pointer to parent directory inode 340 * @chattr - previously saved change attribute 341 * Return "false" if the verifiers doesn't match the change attribute. 342 * This would usually indicate that the directory contents have changed on 343 * the server, and that any dentries need revalidating. 344 */ 345 static inline int nfs_verify_change_attribute(struct inode *dir, unsigned long chattr) 346 { 347 return chattr == NFS_I(dir)->cache_change_attribute; 348 } 349 350 /* 351 * linux/fs/nfs/inode.c 352 */ 353 extern int nfs_sync_mapping(struct address_space *mapping); 354 extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping); 355 extern void nfs_zap_caches(struct inode *); 356 extern void nfs_invalidate_atime(struct inode *); 357 extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *, 358 struct nfs_fattr *); 359 extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *); 360 extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr); 361 extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr); 362 extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *); 363 extern int nfs_permission(struct inode *, int); 364 extern int nfs_open(struct inode *, struct file *); 365 extern int nfs_release(struct inode *, struct file *); 366 extern int nfs_attribute_timeout(struct inode *inode); 367 extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode); 368 extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *); 369 extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping); 370 extern int nfs_setattr(struct dentry *, struct iattr *); 371 extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr); 372 extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx); 373 extern void put_nfs_open_context(struct nfs_open_context *ctx); 374 extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode); 375 extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode); 376 extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx); 377 extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx); 378 extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx); 379 extern u64 nfs_compat_user_ino64(u64 fileid); 380 extern void nfs_fattr_init(struct nfs_fattr *fattr); 381 extern unsigned long nfs_inc_attr_generation_counter(void); 382 383 extern struct nfs_fattr *nfs_alloc_fattr(void); 384 385 static inline void nfs_free_fattr(const struct nfs_fattr *fattr) 386 { 387 kfree(fattr); 388 } 389 390 extern struct nfs_fh *nfs_alloc_fhandle(void); 391 392 static inline void nfs_free_fhandle(const struct nfs_fh *fh) 393 { 394 kfree(fh); 395 } 396 397 #ifdef NFS_DEBUG 398 extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh); 399 static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh) 400 { 401 return _nfs_display_fhandle_hash(fh); 402 } 403 extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption); 404 #define nfs_display_fhandle(fh, caption) \ 405 do { \ 406 if (unlikely(nfs_debug & NFSDBG_FACILITY)) \ 407 _nfs_display_fhandle(fh, caption); \ 408 } while (0) 409 #else 410 static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh) 411 { 412 return 0; 413 } 414 static inline void nfs_display_fhandle(const struct nfs_fh *fh, 415 const char *caption) 416 { 417 } 418 #endif 419 420 /* 421 * linux/fs/nfs/nfsroot.c 422 */ 423 extern int nfs_root_data(char **root_device, char **root_data); /*__init*/ 424 /* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */ 425 extern __be32 root_nfs_parse_addr(char *name); /*__init*/ 426 427 /* 428 * linux/fs/nfs/file.c 429 */ 430 extern const struct inode_operations nfs_file_inode_operations; 431 #ifdef CONFIG_NFS_V3 432 extern const struct inode_operations nfs3_file_inode_operations; 433 #endif /* CONFIG_NFS_V3 */ 434 extern const struct file_operations nfs_file_operations; 435 #ifdef CONFIG_NFS_V4 436 extern const struct file_operations nfs4_file_operations; 437 #endif /* CONFIG_NFS_V4 */ 438 extern const struct address_space_operations nfs_file_aops; 439 extern const struct address_space_operations nfs_dir_aops; 440 441 static inline struct nfs_open_context *nfs_file_open_context(struct file *filp) 442 { 443 return filp->private_data; 444 } 445 446 static inline struct rpc_cred *nfs_file_cred(struct file *file) 447 { 448 if (file != NULL) { 449 struct nfs_open_context *ctx = 450 nfs_file_open_context(file); 451 if (ctx) 452 return ctx->cred; 453 } 454 return NULL; 455 } 456 457 /* 458 * linux/fs/nfs/xattr.c 459 */ 460 #ifdef CONFIG_NFS_V3_ACL 461 extern ssize_t nfs3_listxattr(struct dentry *, char *, size_t); 462 extern ssize_t nfs3_getxattr(struct dentry *, const char *, void *, size_t); 463 extern int nfs3_setxattr(struct dentry *, const char *, 464 const void *, size_t, int); 465 extern int nfs3_removexattr (struct dentry *, const char *name); 466 #else 467 # define nfs3_listxattr NULL 468 # define nfs3_getxattr NULL 469 # define nfs3_setxattr NULL 470 # define nfs3_removexattr NULL 471 #endif 472 473 /* 474 * linux/fs/nfs/direct.c 475 */ 476 extern ssize_t nfs_direct_IO(int, struct kiocb *, const struct iovec *, loff_t, 477 unsigned long); 478 extern ssize_t nfs_file_direct_read(struct kiocb *iocb, 479 const struct iovec *iov, unsigned long nr_segs, 480 loff_t pos); 481 extern ssize_t nfs_file_direct_write(struct kiocb *iocb, 482 const struct iovec *iov, unsigned long nr_segs, 483 loff_t pos); 484 485 /* 486 * linux/fs/nfs/dir.c 487 */ 488 extern const struct inode_operations nfs_dir_inode_operations; 489 #ifdef CONFIG_NFS_V3 490 extern const struct inode_operations nfs3_dir_inode_operations; 491 #endif /* CONFIG_NFS_V3 */ 492 extern const struct file_operations nfs_dir_operations; 493 extern const struct dentry_operations nfs_dentry_operations; 494 495 extern void nfs_force_lookup_revalidate(struct inode *dir); 496 extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh, struct nfs_fattr *fattr); 497 extern int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags); 498 extern void nfs_access_zap_cache(struct inode *inode); 499 500 /* 501 * linux/fs/nfs/symlink.c 502 */ 503 extern const struct inode_operations nfs_symlink_inode_operations; 504 505 /* 506 * linux/fs/nfs/sysctl.c 507 */ 508 #ifdef CONFIG_SYSCTL 509 extern int nfs_register_sysctl(void); 510 extern void nfs_unregister_sysctl(void); 511 #else 512 #define nfs_register_sysctl() 0 513 #define nfs_unregister_sysctl() do { } while(0) 514 #endif 515 516 /* 517 * linux/fs/nfs/namespace.c 518 */ 519 extern const struct inode_operations nfs_mountpoint_inode_operations; 520 extern const struct inode_operations nfs_referral_inode_operations; 521 extern int nfs_mountpoint_expiry_timeout; 522 extern void nfs_release_automount_timer(void); 523 524 /* 525 * linux/fs/nfs/unlink.c 526 */ 527 extern void nfs_complete_unlink(struct dentry *dentry, struct inode *); 528 extern void nfs_block_sillyrename(struct dentry *dentry); 529 extern void nfs_unblock_sillyrename(struct dentry *dentry); 530 extern int nfs_sillyrename(struct inode *dir, struct dentry *dentry); 531 532 /* 533 * linux/fs/nfs/write.c 534 */ 535 extern int nfs_congestion_kb; 536 extern int nfs_writepage(struct page *page, struct writeback_control *wbc); 537 extern int nfs_writepages(struct address_space *, struct writeback_control *); 538 extern int nfs_flush_incompatible(struct file *file, struct page *page); 539 extern int nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int); 540 extern void nfs_writeback_done(struct rpc_task *, struct nfs_write_data *); 541 542 /* 543 * Try to write back everything synchronously (but check the 544 * return value!) 545 */ 546 extern int nfs_wb_all(struct inode *inode); 547 extern int nfs_wb_page(struct inode *inode, struct page* page); 548 extern int nfs_wb_page_cancel(struct inode *inode, struct page* page); 549 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) 550 extern int nfs_commit_inode(struct inode *, int); 551 extern struct nfs_commit_data *nfs_commitdata_alloc(void); 552 extern void nfs_commit_free(struct nfs_commit_data *data); 553 #else 554 static inline int 555 nfs_commit_inode(struct inode *inode, int how) 556 { 557 return 0; 558 } 559 #endif 560 561 static inline int 562 nfs_have_writebacks(struct inode *inode) 563 { 564 return NFS_I(inode)->npages != 0; 565 } 566 567 /* 568 * linux/fs/nfs/read.c 569 */ 570 extern int nfs_readpage(struct file *, struct page *); 571 extern int nfs_readpages(struct file *, struct address_space *, 572 struct list_head *, unsigned); 573 extern int nfs_readpage_result(struct rpc_task *, struct nfs_read_data *); 574 extern int nfs_readpage_async(struct nfs_open_context *, struct inode *, 575 struct page *); 576 577 /* 578 * linux/fs/nfs3proc.c 579 */ 580 #ifdef CONFIG_NFS_V3_ACL 581 extern struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type); 582 extern int nfs3_proc_setacl(struct inode *inode, int type, 583 struct posix_acl *acl); 584 extern int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode, 585 umode_t mode); 586 extern void nfs3_forget_cached_acls(struct inode *inode); 587 #else 588 static inline int nfs3_proc_set_default_acl(struct inode *dir, 589 struct inode *inode, 590 umode_t mode) 591 { 592 return 0; 593 } 594 595 static inline void nfs3_forget_cached_acls(struct inode *inode) 596 { 597 } 598 #endif /* CONFIG_NFS_V3_ACL */ 599 600 /* 601 * inline functions 602 */ 603 604 static inline loff_t nfs_size_to_loff_t(__u64 size) 605 { 606 if (size > (__u64) OFFSET_MAX - 1) 607 return OFFSET_MAX - 1; 608 return (loff_t) size; 609 } 610 611 static inline ino_t 612 nfs_fileid_to_ino_t(u64 fileid) 613 { 614 ino_t ino = (ino_t) fileid; 615 if (sizeof(ino_t) < sizeof(u64)) 616 ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8; 617 return ino; 618 } 619 620 #define NFS_JUKEBOX_RETRY_TIME (5 * HZ) 621 622 #endif /* __KERNEL__ */ 623 624 /* 625 * NFS debug flags 626 */ 627 #define NFSDBG_VFS 0x0001 628 #define NFSDBG_DIRCACHE 0x0002 629 #define NFSDBG_LOOKUPCACHE 0x0004 630 #define NFSDBG_PAGECACHE 0x0008 631 #define NFSDBG_PROC 0x0010 632 #define NFSDBG_XDR 0x0020 633 #define NFSDBG_FILE 0x0040 634 #define NFSDBG_ROOT 0x0080 635 #define NFSDBG_CALLBACK 0x0100 636 #define NFSDBG_CLIENT 0x0200 637 #define NFSDBG_MOUNT 0x0400 638 #define NFSDBG_FSCACHE 0x0800 639 #define NFSDBG_PNFS 0x1000 640 #define NFSDBG_PNFS_LD 0x2000 641 #define NFSDBG_STATE 0x4000 642 #define NFSDBG_ALL 0xFFFF 643 644 #ifdef __KERNEL__ 645 646 # undef ifdebug 647 # ifdef NFS_DEBUG 648 # define ifdebug(fac) if (unlikely(nfs_debug & NFSDBG_##fac)) 649 # define NFS_IFDEBUG(x) x 650 # else 651 # define ifdebug(fac) if (0) 652 # define NFS_IFDEBUG(x) 653 # endif 654 #endif /* __KERNEL */ 655 656 #endif 657