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
  37 #ifdef __KERNEL__
  38
  39 #include <linux/in.h>
  40 #include <linux/mm.h>
  41 #include <linux/pagemap.h>
  42 #include <linux/rbtree.h>
  43 #include <linux/rwsem.h>
  44 #include <linux/wait.h>
  45
  46 #include <linux/sunrpc/debug.h>
  47 #include <linux/sunrpc/auth.h>
  48 #include <linux/sunrpc/clnt.h>
  49
  50 #include <linux/nfs.h>
  51 #include <linux/nfs2.h>
  52 #include <linux/nfs3.h>
  53 #include <linux/nfs4.h>
  54 #include <linux/nfs_xdr.h>
  55 #include <linux/nfs_fs_sb.h>
  56
  57 #include <linux/mempool.h>
  58
  59 /*
  60  * These are the default flags for swap requests
  61  */
  62 #define NFS_RPC_SWAPFLAGS               (RPC_TASK_SWAPPER|RPC_TASK_ROOTCREDS)
  63
  64 /*
  65  * NFSv3/v4 Access mode cache entry
  66  */
  67 struct nfs_access_entry {
  68         struct rb_node          rb_node;
  69         struct list_head        lru;
  70         unsigned long           jiffies;
  71         struct rpc_cred *       cred;
  72         int                     mask;
  73 };
  74
  75 struct nfs4_state;
  76 struct nfs_open_context {
  77         atomic_t count;
  78         struct path path;
  79         struct rpc_cred *cred;
  80         struct nfs4_state *state;
  81         fl_owner_t lockowner;
  82         fmode_t mode;
  83
  84         unsigned long flags;
  85 #define NFS_CONTEXT_ERROR_WRITE         (0)
  86         int error;
  87
  88         struct list_head list;
  89
  90         __u64 dir_cookie;
  91 };
  92
  93 /*
  94  * NFSv4 delegation
  95  */
  96 struct nfs_delegation;
  97
  98 struct posix_acl;
  99
 100 /*
 101  * nfs fs inode data in memory
 102  */
 103 struct nfs_inode {
 104         /*
 105          * The 64bit 'inode number'
 106          */
 107         __u64 fileid;
 108
 109         /*
 110          * NFS file handle
 111          */
 112         struct nfs_fh           fh;
 113
 114         /*
 115          * Various flags
 116          */
 117         unsigned long           flags;                  /* atomic bit ops */
 118         unsigned long           cache_validity;         /* bit mask */
 119
 120         /*
 121          * read_cache_jiffies is when we started read-caching this inode.
 122          * attrtimeo is for how long the cached information is assumed
 123          * to be valid. A successful attribute revalidation doubles
 124          * attrtimeo (up to acregmax/acdirmax), a failure resets it to
 125          * acregmin/acdirmin.
 126          *
 127          * We need to revalidate the cached attrs for this inode if
 128          *
 129          *      jiffies - read_cache_jiffies >= attrtimeo
 130          *
 131          * Please note the comparison is greater than or equal
 132          * so that zero timeout values can be specified.
 133          */
 134         unsigned long           read_cache_jiffies;
 135         unsigned long           attrtimeo;
 136         unsigned long           attrtimeo_timestamp;
 137         __u64                   change_attr;            /* v4 only */
 138
 139         unsigned long           attr_gencount;
 140         /* "Generation counter" for the attribute cache. This is
 141          * bumped whenever we update the metadata on the
 142          * server.
 143          */
 144         unsigned long           cache_change_attribute;
 145
 146         struct rb_root          access_cache;
 147         struct list_head        access_cache_entry_lru;
 148         struct list_head        access_cache_inode_lru;
 149 #ifdef CONFIG_NFS_V3_ACL
 150         struct posix_acl        *acl_access;
 151         struct posix_acl        *acl_default;
 152 #endif
 153
 154         /*
 155          * This is the cookie verifier used for NFSv3 readdir
 156          * operations
 157          */
 158         __be32                  cookieverf[2];
 159
 160         /*
 161          * This is the list of dirty unwritten pages.
 162          */
 163         struct radix_tree_root  nfs_page_tree;
 164
 165         unsigned long           npages;
 166         unsigned long           ncommit;
 167
 168         /* Open contexts for shared mmap writes */
 169         struct list_head        open_files;
 170
 171         /* Number of in-flight sillydelete RPC calls */
 172         atomic_t                silly_count;
 173         /* List of deferred sillydelete requests */
 174         struct hlist_head       silly_list;
 175         wait_queue_head_t       waitqueue;
 176
 177 #ifdef CONFIG_NFS_V4
 178         struct nfs4_cached_acl  *nfs4_acl;
 179         /* NFSv4 state */
 180         struct list_head        open_states;
 181         struct nfs_delegation   *delegation;
 182         fmode_t                  delegation_state;
 183         struct rw_semaphore     rwsem;
 184 #endif /* CONFIG_NFS_V4*/
 185 #ifdef CONFIG_NFS_FSCACHE
 186         struct fscache_cookie   *fscache;
 187 #endif
 188         struct inode            vfs_inode;
 189 };
 190
 191 /*
 192  * Cache validity bit flags
 193  */
 194 #define NFS_INO_INVALID_ATTR    0x0001          /* cached attrs are invalid */
 195 #define NFS_INO_INVALID_DATA    0x0002          /* cached data is invalid */
 196 #define NFS_INO_INVALID_ATIME   0x0004          /* cached atime is invalid */
 197 #define NFS_INO_INVALID_ACCESS  0x0008          /* cached access cred invalid */
 198 #define NFS_INO_INVALID_ACL     0x0010          /* cached acls are invalid */
 199 #define NFS_INO_REVAL_PAGECACHE 0x0020          /* must revalidate pagecache */
 200 #define NFS_INO_REVAL_FORCED    0x0040          /* force revalidation ignoring a delegation */
 201
 202 /*
 203  * Bit offsets in flags field
 204  */
 205 #define NFS_INO_ADVISE_RDPLUS   (0)             /* advise readdirplus */
 206 #define NFS_INO_STALE           (1)             /* possible stale inode */
 207 #define NFS_INO_ACL_LRU_SET     (2)             /* Inode is on the LRU list */
 208 #define NFS_INO_MOUNTPOINT      (3)             /* inode is remote mountpoint */
 209 #define NFS_INO_FLUSHING        (4)             /* inode is flushing out data */
 210 #define NFS_INO_FSCACHE         (5)             /* inode can be cached by FS-Cache */
 211 #define NFS_INO_FSCACHE_LOCK    (6)             /* FS-Cache cookie management lock */
 212 #define NFS_INO_COMMIT          (7)             /* inode is committing unstable writes */
 213
 214 static inline struct nfs_inode *NFS_I(const struct inode *inode)
 215 {
 216         return container_of(inode, struct nfs_inode, vfs_inode);
 217 }
 218
 219 static inline struct nfs_server *NFS_SB(const struct super_block *s)
 220 {
 221         return (struct nfs_server *)(s->s_fs_info);
 222 }
 223
 224 static inline struct nfs_fh *NFS_FH(const struct inode *inode)
 225 {
 226         return &NFS_I(inode)->fh;
 227 }
 228
 229 static inline struct nfs_server *NFS_SERVER(const struct inode *inode)
 230 {
 231         return NFS_SB(inode->i_sb);
 232 }
 233
 234 static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode)
 235 {
 236         return NFS_SERVER(inode)->client;
 237 }
 238
 239 static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode)
 240 {
 241         return NFS_SERVER(inode)->nfs_client->rpc_ops;
 242 }
 243
 244 static inline __be32 *NFS_COOKIEVERF(const struct inode *inode)
 245 {
 246         return NFS_I(inode)->cookieverf;
 247 }
 248
 249 static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode)
 250 {
 251         struct nfs_server *nfss = NFS_SERVER(inode);
 252         return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin;
 253 }
 254
 255 static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode)
 256 {
 257         struct nfs_server *nfss = NFS_SERVER(inode);
 258         return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax;
 259 }
 260
 261 static inline int NFS_STALE(const struct inode *inode)
 262 {
 263         return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
 264 }
 265
 266 static inline int NFS_FSCACHE(const struct inode *inode)
 267 {
 268         return test_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags);
 269 }
 270
 271 static inline __u64 NFS_FILEID(const struct inode *inode)
 272 {
 273         return NFS_I(inode)->fileid;
 274 }
 275
 276 static inline void set_nfs_fileid(struct inode *inode, __u64 fileid)
 277 {
 278         NFS_I(inode)->fileid = fileid;
 279 }
 280
 281 static inline void nfs_mark_for_revalidate(struct inode *inode)
 282 {
 283         struct nfs_inode *nfsi = NFS_I(inode);
 284
 285         spin_lock(&inode->i_lock);
 286         nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS;
 287         if (S_ISDIR(inode->i_mode))
 288                 nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_DATA;
 289         spin_unlock(&inode->i_lock);
 290 }
 291
 292 static inline int nfs_server_capable(struct inode *inode, int cap)
 293 {
 294         return NFS_SERVER(inode)->caps & cap;
 295 }
 296
 297 static inline int NFS_USE_READDIRPLUS(struct inode *inode)
 298 {
 299         return test_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
 300 }
 301
 302 static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
 303 {
 304         dentry->d_time = verf;
 305 }
 306
 307 /**
 308  * nfs_save_change_attribute - Returns the inode attribute change cookie
 309  * @dir - pointer to parent directory inode
 310  * The "change attribute" is updated every time we finish an operation
 311  * that will result in a metadata change on the server.
 312  */
 313 static inline unsigned long nfs_save_change_attribute(struct inode *dir)
 314 {
 315         return NFS_I(dir)->cache_change_attribute;
 316 }
 317
 318 /**
 319  * nfs_verify_change_attribute - Detects NFS remote directory changes
 320  * @dir - pointer to parent directory inode
 321  * @chattr - previously saved change attribute
 322  * Return "false" if the verifiers doesn't match the change attribute.
 323  * This would usually indicate that the directory contents have changed on
 324  * the server, and that any dentries need revalidating.
 325  */
 326 static inline int nfs_verify_change_attribute(struct inode *dir, unsigned long chattr)
 327 {
 328         return chattr == NFS_I(dir)->cache_change_attribute;
 329 }
 330
 331 /*
 332  * linux/fs/nfs/inode.c
 333  */
 334 extern int nfs_sync_mapping(struct address_space *mapping);
 335 extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping);
 336 extern void nfs_zap_caches(struct inode *);
 337 extern void nfs_invalidate_atime(struct inode *);
 338 extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
 339                                 struct nfs_fattr *);
 340 extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
 341 extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
 342 extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
 343 extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
 344 extern int nfs_permission(struct inode *, int);
 345 extern int nfs_open(struct inode *, struct file *);
 346 extern int nfs_release(struct inode *, struct file *);
 347 extern int nfs_attribute_timeout(struct inode *inode);
 348 extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode);
 349 extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
 350 extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
 351 extern int nfs_setattr(struct dentry *, struct iattr *);
 352 extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr);
 353 extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
 354 extern void put_nfs_open_context(struct nfs_open_context *ctx);
 355 extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode);
 356 extern u64 nfs_compat_user_ino64(u64 fileid);
 357 extern void nfs_fattr_init(struct nfs_fattr *fattr);
 358
 359 extern struct nfs_fattr *nfs_alloc_fattr(void);
 360
 361 static inline void nfs_free_fattr(const struct nfs_fattr *fattr)
 362 {
 363         kfree(fattr);
 364 }
 365
 366 extern struct nfs_fh *nfs_alloc_fhandle(void);
 367
 368 static inline void nfs_free_fhandle(const struct nfs_fh *fh)
 369 {
 370         kfree(fh);
 371 }
 372
 373 /* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
 374 extern __be32 root_nfs_parse_addr(char *name); /*__init*/
 375 extern unsigned long nfs_inc_attr_generation_counter(void);
 376
 377 /*
 378  * linux/fs/nfs/file.c
 379  */
 380 extern const struct inode_operations nfs_file_inode_operations;
 381 #ifdef CONFIG_NFS_V3
 382 extern const struct inode_operations nfs3_file_inode_operations;
 383 #endif /* CONFIG_NFS_V3 */
 384 extern const struct file_operations nfs_file_operations;
 385 extern const struct address_space_operations nfs_file_aops;
 386
 387 static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
 388 {
 389         return filp->private_data;
 390 }
 391
 392 static inline struct rpc_cred *nfs_file_cred(struct file *file)
 393 {
 394         if (file != NULL) {
 395                 struct nfs_open_context *ctx =
 396                         nfs_file_open_context(file);
 397                 if (ctx)
 398                         return ctx->cred;
 399         }
 400         return NULL;
 401 }
 402
 403 /*
 404  * linux/fs/nfs/xattr.c
 405  */
 406 #ifdef CONFIG_NFS_V3_ACL
 407 extern ssize_t nfs3_listxattr(struct dentry *, char *, size_t);
 408 extern ssize_t nfs3_getxattr(struct dentry *, const char *, void *, size_t);
 409 extern int nfs3_setxattr(struct dentry *, const char *,
 410                         const void *, size_t, int);
 411 extern int nfs3_removexattr (struct dentry *, const char *name);
 412 #else
 413 # define nfs3_listxattr NULL
 414 # define nfs3_getxattr NULL
 415 # define nfs3_setxattr NULL
 416 # define nfs3_removexattr NULL
 417 #endif
 418
 419 /*
 420  * linux/fs/nfs/direct.c
 421  */
 422 extern ssize_t nfs_direct_IO(int, struct kiocb *, const struct iovec *, loff_t,
 423                         unsigned long);
 424 extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
 425                         const struct iovec *iov, unsigned long nr_segs,
 426                         loff_t pos);
 427 extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
 428                         const struct iovec *iov, unsigned long nr_segs,
 429                         loff_t pos);
 430
 431 /*
 432  * linux/fs/nfs/dir.c
 433  */
 434 extern const struct inode_operations nfs_dir_inode_operations;
 435 #ifdef CONFIG_NFS_V3
 436 extern const struct inode_operations nfs3_dir_inode_operations;
 437 #endif /* CONFIG_NFS_V3 */
 438 extern const struct file_operations nfs_dir_operations;
 439 extern const struct dentry_operations nfs_dentry_operations;
 440
 441 extern void nfs_force_lookup_revalidate(struct inode *dir);
 442 extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh, struct nfs_fattr *fattr);
 443 extern int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags);
 444 extern void nfs_access_zap_cache(struct inode *inode);
 445
 446 /*
 447  * linux/fs/nfs/symlink.c
 448  */
 449 extern const struct inode_operations nfs_symlink_inode_operations;
 450
 451 /*
 452  * linux/fs/nfs/sysctl.c
 453  */
 454 #ifdef CONFIG_SYSCTL
 455 extern int nfs_register_sysctl(void);
 456 extern void nfs_unregister_sysctl(void);
 457 #else
 458 #define nfs_register_sysctl() 0
 459 #define nfs_unregister_sysctl() do { } while(0)
 460 #endif
 461
 462 /*
 463  * linux/fs/nfs/namespace.c
 464  */
 465 extern const struct inode_operations nfs_mountpoint_inode_operations;
 466 extern const struct inode_operations nfs_referral_inode_operations;
 467 extern int nfs_mountpoint_expiry_timeout;
 468 extern void nfs_release_automount_timer(void);
 469
 470 /*
 471  * linux/fs/nfs/unlink.c
 472  */
 473 extern int  nfs_async_unlink(struct inode *dir, struct dentry *dentry);
 474 extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);
 475 extern void nfs_block_sillyrename(struct dentry *dentry);
 476 extern void nfs_unblock_sillyrename(struct dentry *dentry);
 477
 478 /*
 479  * linux/fs/nfs/write.c
 480  */
 481 extern int  nfs_congestion_kb;
 482 extern int  nfs_writepage(struct page *page, struct writeback_control *wbc);
 483 extern int  nfs_writepages(struct address_space *, struct writeback_control *);
 484 extern int  nfs_flush_incompatible(struct file *file, struct page *page);
 485 extern int  nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
 486 extern int nfs_writeback_done(struct rpc_task *, struct nfs_write_data *);
 487
 488 /*
 489  * Try to write back everything synchronously (but check the
 490  * return value!)
 491  */
 492 extern int nfs_wb_all(struct inode *inode);
 493 extern int nfs_wb_page(struct inode *inode, struct page* page);
 494 extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);
 495 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
 496 extern struct nfs_write_data *nfs_commitdata_alloc(void);
 497 extern void nfs_commit_free(struct nfs_write_data *wdata);
 498 #endif
 499
 500 static inline int
 501 nfs_have_writebacks(struct inode *inode)
 502 {
 503         return NFS_I(inode)->npages != 0;
 504 }
 505
 506 /*
 507  * Allocate nfs_write_data structures
 508  */
 509 extern struct nfs_write_data *nfs_writedata_alloc(unsigned int npages);
 510 extern void nfs_writedata_free(struct nfs_write_data *);
 511
 512 /*
 513  * linux/fs/nfs/read.c
 514  */
 515 extern int  nfs_readpage(struct file *, struct page *);
 516 extern int  nfs_readpages(struct file *, struct address_space *,
 517                 struct list_head *, unsigned);
 518 extern int  nfs_readpage_result(struct rpc_task *, struct nfs_read_data *);
 519 extern int  nfs_readpage_async(struct nfs_open_context *, struct inode *,
 520                                struct page *);
 521
 522 /*
 523  * Allocate nfs_read_data structures
 524  */
 525 extern struct nfs_read_data *nfs_readdata_alloc(unsigned int npages);
 526 extern void nfs_readdata_free(struct nfs_read_data *);
 527
 528 /*
 529  * linux/fs/nfs3proc.c
 530  */
 531 #ifdef CONFIG_NFS_V3_ACL
 532 extern struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type);
 533 extern int nfs3_proc_setacl(struct inode *inode, int type,
 534                             struct posix_acl *acl);
 535 extern int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
 536                 mode_t mode);
 537 extern void nfs3_forget_cached_acls(struct inode *inode);
 538 #else
 539 static inline int nfs3_proc_set_default_acl(struct inode *dir,
 540                                             struct inode *inode,
 541                                             mode_t mode)
 542 {
 543         return 0;
 544 }
 545
 546 static inline void nfs3_forget_cached_acls(struct inode *inode)
 547 {
 548 }
 549 #endif /* CONFIG_NFS_V3_ACL */
 550
 551 /*
 552  * inline functions
 553  */
 554
 555 static inline loff_t nfs_size_to_loff_t(__u64 size)
 556 {
 557         if (size > (__u64) OFFSET_MAX - 1)
 558                 return OFFSET_MAX - 1;
 559         return (loff_t) size;
 560 }
 561
 562 static inline ino_t
 563 nfs_fileid_to_ino_t(u64 fileid)
 564 {
 565         ino_t ino = (ino_t) fileid;
 566         if (sizeof(ino_t) < sizeof(u64))
 567                 ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;
 568         return ino;
 569 }
 570
 571 /* NFS root */
 572
 573 extern void * nfs_root_data(void);
 574
 575 #define nfs_wait_event(clnt, wq, condition)                             \
 576 ({                                                                      \
 577         int __retval = wait_event_killable(wq, condition);              \
 578         __retval;                                                       \
 579 })
 580
 581 #define NFS_JUKEBOX_RETRY_TIME (5 * HZ)
 582
 583 #endif /* __KERNEL__ */
 584
 585 /*
 586  * NFS debug flags
 587  */
 588 #define NFSDBG_VFS              0x0001
 589 #define NFSDBG_DIRCACHE         0x0002
 590 #define NFSDBG_LOOKUPCACHE      0x0004
 591 #define NFSDBG_PAGECACHE        0x0008
 592 #define NFSDBG_PROC             0x0010
 593 #define NFSDBG_XDR              0x0020
 594 #define NFSDBG_FILE             0x0040
 595 #define NFSDBG_ROOT             0x0080
 596 #define NFSDBG_CALLBACK         0x0100
 597 #define NFSDBG_CLIENT           0x0200
 598 #define NFSDBG_MOUNT            0x0400
 599 #define NFSDBG_FSCACHE          0x0800
 600 #define NFSDBG_ALL              0xFFFF
 601
 602 #ifdef __KERNEL__
 603
 604 /*
 605  * Enable debugging support for nfs client.
 606  * Requires RPC_DEBUG.
 607  */
 608 #ifdef RPC_DEBUG
 609 # define NFS_DEBUG
 610 #endif
 611
 612 # undef ifdebug
 613 # ifdef NFS_DEBUG
 614 #  define ifdebug(fac)          if (unlikely(nfs_debug & NFSDBG_##fac))
 615 # else
 616 #  define ifdebug(fac)          if (0)
 617 # endif
 618 #endif /* __KERNEL */
 619
 620 #endif