1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * linux/include/linux/nfs_fs.h
4 *
5 * Copyright (C) 1992 Rick Sladkey
6 *
7 * OS-specific nfs filesystem definitions and declarations
8 */
9 #ifndef _LINUX_NFS_FS_H
10 #define _LINUX_NFS_FS_H
11
12 #include <uapi/linux/nfs_fs.h>
13
14
15 /*
16 * Enable dprintk() debugging support for nfs client.
17 */
18 #ifdef CONFIG_NFS_DEBUG
19 # define NFS_DEBUG
20 #endif
21
22 #include <linux/in.h>
23 #include <linux/mm.h>
24 #include <linux/pagemap.h>
25 #include <linux/rbtree.h>
26 #include <linux/refcount.h>
27 #include <linux/rwsem.h>
28 #include <linux/wait.h>
29
30 #include <linux/sunrpc/debug.h>
31 #include <linux/sunrpc/auth.h>
32 #include <linux/sunrpc/clnt.h>
33
34 #include <linux/nfs.h>
35 #include <linux/nfs2.h>
36 #include <linux/nfs3.h>
37 #include <linux/nfs4.h>
38 #include <linux/nfs_xdr.h>
39 #include <linux/nfs_fs_sb.h>
40
41 #include <linux/mempool.h>
42
43 /*
44 * These are the default flags for swap requests
45 */
46 #define NFS_RPC_SWAPFLAGS (RPC_TASK_SWAPPER|RPC_TASK_ROOTCREDS)
47
48 /*
49 * NFSv3/v4 Access mode cache entry
50 */
51 struct nfs_access_entry {
52 struct rb_node rb_node;
53 struct list_head lru;
54 const struct cred * cred;
55 __u32 mask;
56 struct rcu_head rcu_head;
57 };
58
59 struct nfs_lock_context {
60 refcount_t count;
61 struct list_head list;
62 struct nfs_open_context *open_context;
63 fl_owner_t lockowner;
64 atomic_t io_count;
65 struct rcu_head rcu_head;
66 };
67
68 struct nfs4_state;
69 struct nfs_open_context {
70 struct nfs_lock_context lock_context;
71 fl_owner_t flock_owner;
72 struct dentry *dentry;
73 const struct cred *cred;
74 struct rpc_cred *ll_cred; /* low-level cred - use to check for expiry */
75 struct nfs4_state *state;
76 fmode_t mode;
77
78 unsigned long flags;
79 #define NFS_CONTEXT_RESEND_WRITES (1)
80 #define NFS_CONTEXT_BAD (2)
81 #define NFS_CONTEXT_UNLOCK (3)
82 #define NFS_CONTEXT_FILE_OPEN (4)
83 int error;
84
85 struct list_head list;
86 struct nfs4_threshold *mdsthreshold;
87 struct rcu_head rcu_head;
88 };
89
90 struct nfs_open_dir_context {
91 struct list_head list;
92 const struct cred *cred;
93 unsigned long attr_gencount;
94 __u64 dir_cookie;
95 __u64 dup_cookie;
96 signed char duped;
97 };
98
99 /*
100 * NFSv4 delegation
101 */
102 struct nfs_delegation;
103
104 struct posix_acl;
105
106 struct nfs4_xattr_cache;
107
108 /*
109 * nfs fs inode data in memory
110 */
111 struct nfs_inode {
112 /*
113 * The 64bit 'inode number'
114 */
115 __u64 fileid;
116
117 /*
118 * NFS file handle
119 */
120 struct nfs_fh fh;
121
122 /*
123 * Various flags
124 */
125 unsigned long flags; /* atomic bit ops */
126 unsigned long cache_validity; /* bit mask */
127
128 /*
129 * read_cache_jiffies is when we started read-caching this inode.
130 * attrtimeo is for how long the cached information is assumed
131 * to be valid. A successful attribute revalidation doubles
132 * attrtimeo (up to acregmax/acdirmax), a failure resets it to
133 * acregmin/acdirmin.
134 *
135 * We need to revalidate the cached attrs for this inode if
136 *
137 * jiffies - read_cache_jiffies >= attrtimeo
138 *
139 * Please note the comparison is greater than or equal
140 * so that zero timeout values can be specified.
141 */
142 unsigned long read_cache_jiffies;
143 unsigned long attrtimeo;
144 unsigned long attrtimeo_timestamp;
145
146 unsigned long attr_gencount;
147 /* "Generation counter" for the attribute cache. This is
148 * bumped whenever we update the metadata on the
149 * server.
150 */
151 unsigned long cache_change_attribute;
152
153 struct rb_root access_cache;
154 struct list_head access_cache_entry_lru;
155 struct list_head access_cache_inode_lru;
156
157 /*
158 * This is the cookie verifier used for NFSv3 readdir
159 * operations
160 */
161 __be32 cookieverf[2];
162
163 atomic_long_t nrequests;
164 struct nfs_mds_commit_info commit_info;
165
166 /* Open contexts for shared mmap writes */
167 struct list_head open_files;
168
169 /* Readers: in-flight sillydelete RPC calls */
170 /* Writers: rmdir */
171 struct rw_semaphore rmdir_sem;
172 struct mutex commit_mutex;
173
174 /* track last access to cached pages */
175 unsigned long page_index;
176
177 #if IS_ENABLED(CONFIG_NFS_V4)
178 struct nfs4_cached_acl *nfs4_acl;
179 /* NFSv4 state */
180 struct list_head open_states;
181 struct nfs_delegation __rcu *delegation;
182 struct rw_semaphore rwsem;
183
184 /* pNFS layout information */
185 struct pnfs_layout_hdr *layout;
186 #endif /* CONFIG_NFS_V4*/
187 /* how many bytes have been written/read and how many bytes queued up */
188 __u64 write_io;
189 __u64 read_io;
190 #ifdef CONFIG_NFS_FSCACHE
191 struct fscache_cookie *fscache;
192 #endif
193 struct inode vfs_inode;
194
195 #ifdef CONFIG_NFS_V4_2
196 struct nfs4_xattr_cache *xattr_cache;
197 #endif
198 };
199
200 struct nfs4_copy_state {
201 struct list_head copies;
202 struct list_head src_copies;
203 nfs4_stateid stateid;
204 struct completion completion;
205 uint64_t count;
206 struct nfs_writeverf verf;
207 int error;
208 int flags;
209 struct nfs4_state *parent_src_state;
210 struct nfs4_state *parent_dst_state;
211 };
212
213 /*
214 * Access bit flags
215 */
216 #define NFS_ACCESS_READ 0x0001
217 #define NFS_ACCESS_LOOKUP 0x0002
218 #define NFS_ACCESS_MODIFY 0x0004
219 #define NFS_ACCESS_EXTEND 0x0008
220 #define NFS_ACCESS_DELETE 0x0010
221 #define NFS_ACCESS_EXECUTE 0x0020
222 #define NFS_ACCESS_XAREAD 0x0040
223 #define NFS_ACCESS_XAWRITE 0x0080
224 #define NFS_ACCESS_XALIST 0x0100
225
226 /*
227 * Cache validity bit flags
228 */
229 #define NFS_INO_INVALID_DATA BIT(1) /* cached data is invalid */
230 #define NFS_INO_INVALID_ATIME BIT(2) /* cached atime is invalid */
231 #define NFS_INO_INVALID_ACCESS BIT(3) /* cached access cred invalid */
232 #define NFS_INO_INVALID_ACL BIT(4) /* cached acls are invalid */
233 #define NFS_INO_REVAL_PAGECACHE BIT(5) /* must revalidate pagecache */
234 #define NFS_INO_REVAL_FORCED BIT(6) /* force revalidation ignoring a delegation */
235 #define NFS_INO_INVALID_LABEL BIT(7) /* cached label is invalid */
236 #define NFS_INO_INVALID_CHANGE BIT(8) /* cached change is invalid */
237 #define NFS_INO_INVALID_CTIME BIT(9) /* cached ctime is invalid */
238 #define NFS_INO_INVALID_MTIME BIT(10) /* cached mtime is invalid */
239 #define NFS_INO_INVALID_SIZE BIT(11) /* cached size is invalid */
240 #define NFS_INO_INVALID_OTHER BIT(12) /* other attrs are invalid */
241 #define NFS_INO_DATA_INVAL_DEFER \
242 BIT(13) /* Deferred cache invalidation */
243 #define NFS_INO_INVALID_BLOCKS BIT(14) /* cached blocks are invalid */
244 #define NFS_INO_INVALID_XATTR BIT(15) /* xattrs are invalid */
245
246 #define NFS_INO_INVALID_ATTR (NFS_INO_INVALID_CHANGE \
247 | NFS_INO_INVALID_CTIME \
248 | NFS_INO_INVALID_MTIME \
249 | NFS_INO_INVALID_SIZE \
250 | NFS_INO_INVALID_OTHER) /* inode metadata is invalid */
251
252 /*
253 * Bit offsets in flags field
254 */
255 #define NFS_INO_ADVISE_RDPLUS (0) /* advise readdirplus */
256 #define NFS_INO_STALE (1) /* possible stale inode */
257 #define NFS_INO_ACL_LRU_SET (2) /* Inode is on the LRU list */
258 #define NFS_INO_INVALIDATING (3) /* inode is being invalidated */
259 #define NFS_INO_FSCACHE (5) /* inode can be cached by FS-Cache */
260 #define NFS_INO_FSCACHE_LOCK (6) /* FS-Cache cookie management lock */
261 #define NFS_INO_LAYOUTCOMMIT (9) /* layoutcommit required */
262 #define NFS_INO_LAYOUTCOMMITTING (10) /* layoutcommit inflight */
263 #define NFS_INO_LAYOUTSTATS (11) /* layoutstats inflight */
264 #define NFS_INO_ODIRECT (12) /* I/O setting is O_DIRECT */
265
NFS_I(const struct inode * inode)266 static inline struct nfs_inode *NFS_I(const struct inode *inode)
267 {
268 return container_of(inode, struct nfs_inode, vfs_inode);
269 }
270
NFS_SB(const struct super_block * s)271 static inline struct nfs_server *NFS_SB(const struct super_block *s)
272 {
273 return (struct nfs_server *)(s->s_fs_info);
274 }
275
NFS_FH(const struct inode * inode)276 static inline struct nfs_fh *NFS_FH(const struct inode *inode)
277 {
278 return &NFS_I(inode)->fh;
279 }
280
NFS_SERVER(const struct inode * inode)281 static inline struct nfs_server *NFS_SERVER(const struct inode *inode)
282 {
283 return NFS_SB(inode->i_sb);
284 }
285
NFS_CLIENT(const struct inode * inode)286 static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode)
287 {
288 return NFS_SERVER(inode)->client;
289 }
290
NFS_PROTO(const struct inode * inode)291 static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode)
292 {
293 return NFS_SERVER(inode)->nfs_client->rpc_ops;
294 }
295
NFS_MINATTRTIMEO(const struct inode * inode)296 static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode)
297 {
298 struct nfs_server *nfss = NFS_SERVER(inode);
299 return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin;
300 }
301
NFS_MAXATTRTIMEO(const struct inode * inode)302 static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode)
303 {
304 struct nfs_server *nfss = NFS_SERVER(inode);
305 return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax;
306 }
307
NFS_STALE(const struct inode * inode)308 static inline int NFS_STALE(const struct inode *inode)
309 {
310 return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
311 }
312
nfs_i_fscache(struct inode * inode)313 static inline struct fscache_cookie *nfs_i_fscache(struct inode *inode)
314 {
315 #ifdef CONFIG_NFS_FSCACHE
316 return NFS_I(inode)->fscache;
317 #else
318 return NULL;
319 #endif
320 }
321
NFS_FILEID(const struct inode * inode)322 static inline __u64 NFS_FILEID(const struct inode *inode)
323 {
324 return NFS_I(inode)->fileid;
325 }
326
set_nfs_fileid(struct inode * inode,__u64 fileid)327 static inline void set_nfs_fileid(struct inode *inode, __u64 fileid)
328 {
329 NFS_I(inode)->fileid = fileid;
330 }
331
nfs_mark_for_revalidate(struct inode * inode)332 static inline void nfs_mark_for_revalidate(struct inode *inode)
333 {
334 struct nfs_inode *nfsi = NFS_I(inode);
335
336 spin_lock(&inode->i_lock);
337 nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE
338 | NFS_INO_INVALID_ACCESS
339 | NFS_INO_INVALID_ACL
340 | NFS_INO_INVALID_CHANGE
341 | NFS_INO_INVALID_CTIME;
342 if (S_ISDIR(inode->i_mode))
343 nfsi->cache_validity |= NFS_INO_INVALID_DATA;
344 spin_unlock(&inode->i_lock);
345 }
346
nfs_server_capable(struct inode * inode,int cap)347 static inline int nfs_server_capable(struct inode *inode, int cap)
348 {
349 return NFS_SERVER(inode)->caps & cap;
350 }
351
352 /**
353 * nfs_save_change_attribute - Returns the inode attribute change cookie
354 * @dir - pointer to parent directory inode
355 * The "cache change attribute" is updated when we need to revalidate
356 * our dentry cache after a directory was seen to change on the server.
357 */
nfs_save_change_attribute(struct inode * dir)358 static inline unsigned long nfs_save_change_attribute(struct inode *dir)
359 {
360 return NFS_I(dir)->cache_change_attribute;
361 }
362
363 /*
364 * linux/fs/nfs/inode.c
365 */
366 extern int nfs_sync_mapping(struct address_space *mapping);
367 extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping);
368 extern void nfs_zap_caches(struct inode *);
369 extern void nfs_set_inode_stale(struct inode *inode);
370 extern void nfs_invalidate_atime(struct inode *);
371 extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
372 struct nfs_fattr *, struct nfs4_label *);
373 struct inode *nfs_ilookup(struct super_block *sb, struct nfs_fattr *, struct nfs_fh *);
374 extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
375 extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
376 extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
377 extern int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr);
378 extern int nfs_getattr(const struct path *, struct kstat *, u32, unsigned int);
379 extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *);
380 extern void nfs_access_set_mask(struct nfs_access_entry *, u32);
381 extern int nfs_permission(struct inode *, int);
382 extern int nfs_open(struct inode *, struct file *);
383 extern int nfs_attribute_cache_expired(struct inode *inode);
384 extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode);
385 extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
386 extern bool nfs_mapping_need_revalidate_inode(struct inode *inode);
387 extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
388 extern int nfs_revalidate_mapping_rcu(struct inode *inode);
389 extern int nfs_setattr(struct dentry *, struct iattr *);
390 extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *);
391 extern void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
392 struct nfs4_label *label);
393 extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
394 extern void put_nfs_open_context(struct nfs_open_context *ctx);
395 extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode);
396 extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode, struct file *filp);
397 extern void nfs_inode_attach_open_context(struct nfs_open_context *ctx);
398 extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);
399 extern void nfs_file_clear_open_context(struct file *flip);
400 extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx);
401 extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx);
402 extern u64 nfs_compat_user_ino64(u64 fileid);
403 extern void nfs_fattr_init(struct nfs_fattr *fattr);
404 extern void nfs_fattr_set_barrier(struct nfs_fattr *fattr);
405 extern unsigned long nfs_inc_attr_generation_counter(void);
406
407 extern struct nfs_fattr *nfs_alloc_fattr(void);
408
nfs_free_fattr(const struct nfs_fattr * fattr)409 static inline void nfs_free_fattr(const struct nfs_fattr *fattr)
410 {
411 kfree(fattr);
412 }
413
414 extern struct nfs_fh *nfs_alloc_fhandle(void);
415
nfs_free_fhandle(const struct nfs_fh * fh)416 static inline void nfs_free_fhandle(const struct nfs_fh *fh)
417 {
418 kfree(fh);
419 }
420
421 #ifdef NFS_DEBUG
422 extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh);
nfs_display_fhandle_hash(const struct nfs_fh * fh)423 static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
424 {
425 return _nfs_display_fhandle_hash(fh);
426 }
427 extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption);
428 #define nfs_display_fhandle(fh, caption) \
429 do { \
430 if (unlikely(nfs_debug & NFSDBG_FACILITY)) \
431 _nfs_display_fhandle(fh, caption); \
432 } while (0)
433 #else
nfs_display_fhandle_hash(const struct nfs_fh * fh)434 static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
435 {
436 return 0;
437 }
nfs_display_fhandle(const struct nfs_fh * fh,const char * caption)438 static inline void nfs_display_fhandle(const struct nfs_fh *fh,
439 const char *caption)
440 {
441 }
442 #endif
443
444 /*
445 * linux/fs/nfs/nfsroot.c
446 */
447 extern int nfs_root_data(char **root_device, char **root_data); /*__init*/
448 /* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
449 extern __be32 root_nfs_parse_addr(char *name); /*__init*/
450
451 /*
452 * linux/fs/nfs/file.c
453 */
454 extern const struct file_operations nfs_file_operations;
455 #if IS_ENABLED(CONFIG_NFS_V4)
456 extern const struct file_operations nfs4_file_operations;
457 #endif /* CONFIG_NFS_V4 */
458 extern const struct address_space_operations nfs_file_aops;
459 extern const struct address_space_operations nfs_dir_aops;
460
nfs_file_open_context(struct file * filp)461 static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
462 {
463 return filp->private_data;
464 }
465
nfs_file_cred(struct file * file)466 static inline const struct cred *nfs_file_cred(struct file *file)
467 {
468 if (file != NULL) {
469 struct nfs_open_context *ctx =
470 nfs_file_open_context(file);
471 if (ctx)
472 return ctx->cred;
473 }
474 return NULL;
475 }
476
477 /*
478 * linux/fs/nfs/direct.c
479 */
480 extern ssize_t nfs_direct_IO(struct kiocb *, struct iov_iter *);
481 ssize_t nfs_file_direct_read(struct kiocb *iocb,
482 struct iov_iter *iter, bool swap);
483 ssize_t nfs_file_direct_write(struct kiocb *iocb,
484 struct iov_iter *iter, bool swap);
485
486 /*
487 * linux/fs/nfs/dir.c
488 */
489 extern const struct file_operations nfs_dir_operations;
490 extern const struct dentry_operations nfs_dentry_operations;
491
492 extern void nfs_force_lookup_revalidate(struct inode *dir);
493 extern void nfs_set_verifier(struct dentry * dentry, unsigned long verf);
494 #if IS_ENABLED(CONFIG_NFS_V4)
495 extern void nfs_clear_verifier_delegated(struct inode *inode);
496 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
497 extern struct dentry *nfs_add_or_obtain(struct dentry *dentry,
498 struct nfs_fh *fh, struct nfs_fattr *fattr,
499 struct nfs4_label *label);
500 extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh,
501 struct nfs_fattr *fattr, struct nfs4_label *label);
502 extern int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags);
503 extern void nfs_access_zap_cache(struct inode *inode);
504 extern int nfs_access_get_cached(struct inode *inode, const struct cred *cred,
505 u32 *mask, bool may_block);
506
507 /*
508 * linux/fs/nfs/symlink.c
509 */
510 extern const struct inode_operations nfs_symlink_inode_operations;
511
512 /*
513 * linux/fs/nfs/sysctl.c
514 */
515 #ifdef CONFIG_SYSCTL
516 extern int nfs_register_sysctl(void);
517 extern void nfs_unregister_sysctl(void);
518 #else
519 #define nfs_register_sysctl() 0
520 #define nfs_unregister_sysctl() do { } while(0)
521 #endif
522
523 /*
524 * linux/fs/nfs/namespace.c
525 */
526 extern const struct inode_operations nfs_mountpoint_inode_operations;
527 extern const struct inode_operations nfs_referral_inode_operations;
528 extern int nfs_mountpoint_expiry_timeout;
529 extern void nfs_release_automount_timer(void);
530
531 /*
532 * linux/fs/nfs/unlink.c
533 */
534 extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);
535
536 /*
537 * linux/fs/nfs/write.c
538 */
539 extern int nfs_congestion_kb;
540 extern int nfs_writepage(struct page *page, struct writeback_control *wbc);
541 extern int nfs_writepages(struct address_space *, struct writeback_control *);
542 extern int nfs_flush_incompatible(struct file *file, struct page *page);
543 extern int nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
544
545 /*
546 * Try to write back everything synchronously (but check the
547 * return value!)
548 */
549 extern int nfs_sync_inode(struct inode *inode);
550 extern int nfs_wb_all(struct inode *inode);
551 extern int nfs_wb_page(struct inode *inode, struct page *page);
552 extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);
553 extern int nfs_commit_inode(struct inode *, int);
554 extern struct nfs_commit_data *nfs_commitdata_alloc(void);
555 extern void nfs_commit_free(struct nfs_commit_data *data);
556 bool nfs_commit_end(struct nfs_mds_commit_info *cinfo);
557
558 static inline int
nfs_have_writebacks(struct inode * inode)559 nfs_have_writebacks(struct inode *inode)
560 {
561 return atomic_long_read(&NFS_I(inode)->nrequests) != 0;
562 }
563
564 /*
565 * linux/fs/nfs/read.c
566 */
567 extern int nfs_readpage(struct file *, struct page *);
568 extern int nfs_readpages(struct file *, struct address_space *,
569 struct list_head *, unsigned);
570 extern int nfs_readpage_async(struct nfs_open_context *, struct inode *,
571 struct page *);
572
573 /*
574 * inline functions
575 */
576
nfs_size_to_loff_t(__u64 size)577 static inline loff_t nfs_size_to_loff_t(__u64 size)
578 {
579 return min_t(u64, size, OFFSET_MAX);
580 }
581
582 static inline ino_t
nfs_fileid_to_ino_t(u64 fileid)583 nfs_fileid_to_ino_t(u64 fileid)
584 {
585 ino_t ino = (ino_t) fileid;
586 if (sizeof(ino_t) < sizeof(u64))
587 ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;
588 return ino;
589 }
590
591 #define NFS_JUKEBOX_RETRY_TIME (5 * HZ)
592
593
594 # undef ifdebug
595 # ifdef NFS_DEBUG
596 # define ifdebug(fac) if (unlikely(nfs_debug & NFSDBG_##fac))
597 # define NFS_IFDEBUG(x) x
598 # else
599 # define ifdebug(fac) if (0)
600 # define NFS_IFDEBUG(x)
601 # endif
602 #endif
603