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