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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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/config.h>
13#include <linux/in.h>
14#include <linux/mm.h>
15#include <linux/pagemap.h>
16#include <linux/rwsem.h>
17#include <linux/wait.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
19#include <linux/nfs_fs_sb.h>
20
21#include <linux/sunrpc/debug.h>
22#include <linux/sunrpc/auth.h>
23#include <linux/sunrpc/clnt.h>
24
25#include <linux/nfs.h>
26#include <linux/nfs2.h>
27#include <linux/nfs3.h>
28#include <linux/nfs4.h>
29#include <linux/nfs_xdr.h>
30#include <linux/rwsem.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/mempool.h>
32
33/*
34 * Enable debugging support for nfs client.
35 * Requires RPC_DEBUG.
36 */
37#ifdef RPC_DEBUG
38# define NFS_DEBUG
39#endif
40
41#define NFS_MAX_FILE_IO_BUFFER_SIZE 32768
42#define NFS_DEF_FILE_IO_BUFFER_SIZE 4096
43
44/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 * superblock magic number for NFS
46 */
47#define NFS_SUPER_MAGIC 0x6969
48
49/*
50 * These are the default flags for swap requests
51 */
52#define NFS_RPC_SWAPFLAGS (RPC_TASK_SWAPPER|RPC_TASK_ROOTCREDS)
53
Linus Torvalds1da177e2005-04-16 15:20:36 -070054/*
55 * When flushing a cluster of dirty pages, there can be different
56 * strategies:
57 */
58#define FLUSH_AGING 0 /* only flush old buffers */
59#define FLUSH_SYNC 1 /* file being synced, or contention */
60#define FLUSH_WAIT 2 /* wait for completion */
61#define FLUSH_STABLE 4 /* commit to stable storage */
62#define FLUSH_LOWPRI 8 /* low priority background flush */
63#define FLUSH_HIGHPRI 16 /* high priority memory reclaim flush */
64
65#ifdef __KERNEL__
66
67/*
68 * NFSv3/v4 Access mode cache entry
69 */
70struct nfs_access_entry {
71 unsigned long jiffies;
72 struct rpc_cred * cred;
73 int mask;
74};
75
76struct nfs4_state;
77struct nfs_open_context {
78 atomic_t count;
79 struct dentry *dentry;
80 struct rpc_cred *cred;
81 struct nfs4_state *state;
82 fl_owner_t lockowner;
83 int mode;
84 int error;
85
86 struct list_head list;
Olivier Galibert00a92642005-06-22 17:16:29 +000087
Olivier Galibert00a92642005-06-22 17:16:29 +000088 __u64 dir_cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -070089};
90
91/*
92 * NFSv4 delegation
93 */
94struct nfs_delegation;
95
Andreas Gruenbacher5c6a9f72005-06-22 17:16:27 +000096struct posix_acl;
97
Linus Torvalds1da177e2005-04-16 15:20:36 -070098/*
99 * nfs fs inode data in memory
100 */
101struct nfs_inode {
102 /*
103 * The 64bit 'inode number'
104 */
105 __u64 fileid;
106
107 /*
108 * NFS file handle
109 */
110 struct nfs_fh fh;
111
112 /*
113 * Various flags
114 */
Chuck Lever412d5822005-08-18 11:24:11 -0700115 unsigned long flags; /* atomic bit ops */
116 unsigned long cache_validity; /* bit mask */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
118 /*
119 * read_cache_jiffies is when we started read-caching this inode,
120 * and read_cache_mtime is the mtime of the inode at that time.
121 * attrtimeo is for how long the cached information is assumed
122 * to be valid. A successful attribute revalidation doubles
123 * attrtimeo (up to acregmax/acdirmax), a failure resets it to
124 * acregmin/acdirmin.
125 *
126 * We need to revalidate the cached attrs for this inode if
127 *
128 * jiffies - read_cache_jiffies > attrtimeo
129 *
130 * and invalidate any cached data/flush out any dirty pages if
131 * we find that
132 *
133 * mtime != read_cache_mtime
134 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 unsigned long read_cache_jiffies;
136 unsigned long attrtimeo;
137 unsigned long attrtimeo_timestamp;
138 __u64 change_attr; /* v4 only */
139
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 * Counter indicating the number of outstanding requests that
147 * will cause a file data update.
148 */
149 atomic_t data_updates;
150
151 struct nfs_access_entry cache_access;
Andreas Gruenbacher5c6a9f72005-06-22 17:16:27 +0000152#ifdef CONFIG_NFS_V3_ACL
153 struct posix_acl *acl_access;
154 struct posix_acl *acl_default;
155#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
157 /*
158 * This is the cookie verifier used for NFSv3 readdir
159 * operations
160 */
161 __u32 cookieverf[2];
162
163 /*
164 * This is the list of dirty unwritten pages.
165 */
166 spinlock_t req_lock;
167 struct list_head dirty;
168 struct list_head commit;
169 struct radix_tree_root nfs_page_tree;
170
171 unsigned int ndirty,
172 ncommit,
173 npages;
174
175 /* Open contexts for shared mmap writes */
176 struct list_head open_files;
177
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178#ifdef CONFIG_NFS_V4
J. Bruce Fieldse50a1c22005-06-22 17:16:23 +0000179 struct nfs4_cached_acl *nfs4_acl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 /* NFSv4 state */
181 struct list_head open_states;
182 struct nfs_delegation *delegation;
183 int delegation_state;
184 struct rw_semaphore rwsem;
185#endif /* CONFIG_NFS_V4*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 struct inode vfs_inode;
187};
188
189/*
Chuck Lever55296802005-08-18 11:24:09 -0700190 * Cache validity bit flags
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 */
Chuck Lever55296802005-08-18 11:24:09 -0700192#define NFS_INO_INVALID_ATTR 0x0001 /* cached attrs are invalid */
193#define NFS_INO_INVALID_DATA 0x0002 /* cached data is invalid */
194#define NFS_INO_INVALID_ATIME 0x0004 /* cached atime is invalid */
195#define NFS_INO_INVALID_ACCESS 0x0008 /* cached access cred invalid */
196#define NFS_INO_INVALID_ACL 0x0010 /* cached acls are invalid */
197#define NFS_INO_REVAL_PAGECACHE 0x0020 /* must revalidate pagecache */
198
199/*
Chuck Lever412d5822005-08-18 11:24:11 -0700200 * Bit offsets in flags field
Chuck Lever55296802005-08-18 11:24:09 -0700201 */
Chuck Lever412d5822005-08-18 11:24:11 -0700202#define NFS_INO_REVALIDATING (0) /* revalidating attrs */
203#define NFS_INO_ADVISE_RDPLUS (1) /* advise readdirplus */
204#define NFS_INO_STALE (2) /* possible stale inode */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
206static inline struct nfs_inode *NFS_I(struct inode *inode)
207{
208 return container_of(inode, struct nfs_inode, vfs_inode);
209}
210#define NFS_SB(s) ((struct nfs_server *)(s->s_fs_info))
211
212#define NFS_FH(inode) (&NFS_I(inode)->fh)
213#define NFS_SERVER(inode) (NFS_SB(inode->i_sb))
214#define NFS_CLIENT(inode) (NFS_SERVER(inode)->client)
215#define NFS_PROTO(inode) (NFS_SERVER(inode)->rpc_ops)
216#define NFS_ADDR(inode) (RPC_PEERADDR(NFS_CLIENT(inode)))
217#define NFS_COOKIEVERF(inode) (NFS_I(inode)->cookieverf)
218#define NFS_READTIME(inode) (NFS_I(inode)->read_cache_jiffies)
219#define NFS_CHANGE_ATTR(inode) (NFS_I(inode)->change_attr)
220#define NFS_ATTRTIMEO(inode) (NFS_I(inode)->attrtimeo)
221#define NFS_MINATTRTIMEO(inode) \
222 (S_ISDIR(inode->i_mode)? NFS_SERVER(inode)->acdirmin \
223 : NFS_SERVER(inode)->acregmin)
224#define NFS_MAXATTRTIMEO(inode) \
225 (S_ISDIR(inode->i_mode)? NFS_SERVER(inode)->acdirmax \
226 : NFS_SERVER(inode)->acregmax)
227#define NFS_ATTRTIMEO_UPDATE(inode) (NFS_I(inode)->attrtimeo_timestamp)
228
229#define NFS_FLAGS(inode) (NFS_I(inode)->flags)
Chuck Lever412d5822005-08-18 11:24:11 -0700230#define NFS_STALE(inode) (test_bit(NFS_INO_STALE, &NFS_FLAGS(inode)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
232#define NFS_FILEID(inode) (NFS_I(inode)->fileid)
233
234static inline int nfs_caches_unstable(struct inode *inode)
235{
236 return atomic_read(&NFS_I(inode)->data_updates) != 0;
237}
238
239static inline void NFS_CACHEINV(struct inode *inode)
240{
Chuck Leverdc592502005-08-18 11:24:12 -0700241 if (!nfs_caches_unstable(inode)) {
242 spin_lock(&inode->i_lock);
Chuck Lever55296802005-08-18 11:24:09 -0700243 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATTR | NFS_INO_INVALID_ACCESS;
Chuck Leverdc592502005-08-18 11:24:12 -0700244 spin_unlock(&inode->i_lock);
245 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246}
247
248static inline int nfs_server_capable(struct inode *inode, int cap)
249{
250 return NFS_SERVER(inode)->caps & cap;
251}
252
253static inline int NFS_USE_READDIRPLUS(struct inode *inode)
254{
Chuck Lever412d5822005-08-18 11:24:11 -0700255 return test_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256}
257
258/**
259 * nfs_save_change_attribute - Returns the inode attribute change cookie
260 * @inode - pointer to inode
261 * The "change attribute" is updated every time we finish an operation
262 * that will result in a metadata change on the server.
263 */
264static inline long nfs_save_change_attribute(struct inode *inode)
265{
266 return NFS_I(inode)->cache_change_attribute;
267}
268
269/**
270 * nfs_verify_change_attribute - Detects NFS inode cache updates
271 * @inode - pointer to inode
272 * @chattr - previously saved change attribute
273 * Return "false" if metadata has been updated (or is in the process of
274 * being updated) since the change attribute was saved.
275 */
276static inline int nfs_verify_change_attribute(struct inode *inode, unsigned long chattr)
277{
278 return !nfs_caches_unstable(inode)
279 && chattr == NFS_I(inode)->cache_change_attribute;
280}
281
282/*
283 * linux/fs/nfs/inode.c
284 */
285extern void nfs_zap_caches(struct inode *);
286extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
287 struct nfs_fattr *);
288extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
289extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
290extern int nfs_permission(struct inode *, int, struct nameidata *);
291extern int nfs_access_get_cached(struct inode *, struct rpc_cred *, struct nfs_access_entry *);
292extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *);
293extern int nfs_open(struct inode *, struct file *);
294extern int nfs_release(struct inode *, struct file *);
295extern int nfs_attribute_timeout(struct inode *inode);
296extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode);
297extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
Trond Myklebust7d52e862005-06-22 17:16:30 +0000298extern void nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299extern int nfs_setattr(struct dentry *, struct iattr *);
Trond Myklebust65e43082005-08-16 11:49:44 -0400300extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301extern void nfs_begin_attr_update(struct inode *);
302extern void nfs_end_attr_update(struct inode *);
303extern void nfs_begin_data_update(struct inode *);
304extern void nfs_end_data_update(struct inode *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, struct rpc_cred *cred);
306extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
307extern void put_nfs_open_context(struct nfs_open_context *ctx);
308extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);
309extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, int mode);
310extern void nfs_file_clear_open_context(struct file *filp);
311
312/* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
313extern u32 root_nfs_parse_addr(char *name); /*__init*/
314
315/*
316 * linux/fs/nfs/file.c
317 */
318extern struct inode_operations nfs_file_inode_operations;
Andreas Gruenbacherb7fa0552005-06-22 17:16:27 +0000319#ifdef CONFIG_NFS_V3
320extern struct inode_operations nfs3_file_inode_operations;
321#endif /* CONFIG_NFS_V3 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322extern struct file_operations nfs_file_operations;
323extern struct address_space_operations nfs_file_aops;
324
325static inline struct rpc_cred *nfs_file_cred(struct file *file)
326{
327 if (file != NULL) {
328 struct nfs_open_context *ctx;
329
330 ctx = (struct nfs_open_context*)file->private_data;
331 return ctx->cred;
332 }
333 return NULL;
334}
335
336/*
Andreas Gruenbacherb7fa0552005-06-22 17:16:27 +0000337 * linux/fs/nfs/xattr.c
338 */
339#ifdef CONFIG_NFS_V3_ACL
340extern ssize_t nfs3_listxattr(struct dentry *, char *, size_t);
341extern ssize_t nfs3_getxattr(struct dentry *, const char *, void *, size_t);
342extern int nfs3_setxattr(struct dentry *, const char *,
343 const void *, size_t, int);
344extern int nfs3_removexattr (struct dentry *, const char *name);
345#else
346# define nfs3_listxattr NULL
347# define nfs3_getxattr NULL
348# define nfs3_setxattr NULL
349# define nfs3_removexattr NULL
350#endif
351
352/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 * linux/fs/nfs/direct.c
354 */
355extern ssize_t nfs_direct_IO(int, struct kiocb *, const struct iovec *, loff_t,
356 unsigned long);
357extern ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf,
358 size_t count, loff_t pos);
359extern ssize_t nfs_file_direct_write(struct kiocb *iocb, const char __user *buf,
360 size_t count, loff_t pos);
361
362/*
363 * linux/fs/nfs/dir.c
364 */
365extern struct inode_operations nfs_dir_inode_operations;
Andreas Gruenbacherb7fa0552005-06-22 17:16:27 +0000366#ifdef CONFIG_NFS_V3
367extern struct inode_operations nfs3_dir_inode_operations;
368#endif /* CONFIG_NFS_V3 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369extern struct file_operations nfs_dir_operations;
370extern struct dentry_operations nfs_dentry_operations;
371
372extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh, struct nfs_fattr *fattr);
373
374/*
375 * linux/fs/nfs/symlink.c
376 */
377extern struct inode_operations nfs_symlink_inode_operations;
378
379/*
380 * linux/fs/nfs/unlink.c
381 */
382extern int nfs_async_unlink(struct dentry *);
383extern void nfs_complete_unlink(struct dentry *);
384
385/*
386 * linux/fs/nfs/write.c
387 */
388extern int nfs_writepage(struct page *page, struct writeback_control *wbc);
389extern int nfs_writepages(struct address_space *, struct writeback_control *);
390extern int nfs_flush_incompatible(struct file *file, struct page *page);
391extern int nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
392extern void nfs_writeback_done(struct rpc_task *task);
393
394#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
395extern void nfs_commit_done(struct rpc_task *);
396#endif
397
398/*
399 * Try to write back everything synchronously (but check the
400 * return value!)
401 */
402extern int nfs_sync_inode(struct inode *, unsigned long, unsigned int, int);
403#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
Trond Myklebust3da28eb2005-06-22 17:16:31 +0000404extern int nfs_commit_inode(struct inode *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405#else
406static inline int
Trond Myklebust3da28eb2005-06-22 17:16:31 +0000407nfs_commit_inode(struct inode *inode, int how)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408{
409 return 0;
410}
411#endif
412
413static inline int
414nfs_have_writebacks(struct inode *inode)
415{
416 return NFS_I(inode)->npages != 0;
417}
418
419static inline int
420nfs_wb_all(struct inode *inode)
421{
422 int error = nfs_sync_inode(inode, 0, 0, FLUSH_WAIT);
423 return (error < 0) ? error : 0;
424}
425
426/*
427 * Write back all requests on one page - we do this before reading it.
428 */
429static inline int nfs_wb_page_priority(struct inode *inode, struct page* page, int how)
430{
431 int error = nfs_sync_inode(inode, page->index, 1,
432 how | FLUSH_WAIT | FLUSH_STABLE);
433 return (error < 0) ? error : 0;
434}
435
436static inline int nfs_wb_page(struct inode *inode, struct page* page)
437{
438 return nfs_wb_page_priority(inode, page, 0);
439}
440
441/*
442 * Allocate and free nfs_write_data structures
443 */
444extern mempool_t *nfs_wdata_mempool;
445
446static inline struct nfs_write_data *nfs_writedata_alloc(void)
447{
448 struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, SLAB_NOFS);
449 if (p) {
450 memset(p, 0, sizeof(*p));
451 INIT_LIST_HEAD(&p->pages);
452 }
453 return p;
454}
455
456static inline void nfs_writedata_free(struct nfs_write_data *p)
457{
458 mempool_free(p, nfs_wdata_mempool);
459}
460
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461/*
462 * linux/fs/nfs/read.c
463 */
464extern int nfs_readpage(struct file *, struct page *);
465extern int nfs_readpages(struct file *, struct address_space *,
466 struct list_head *, unsigned);
467extern void nfs_readpage_result(struct rpc_task *);
468
469/*
470 * Allocate and free nfs_read_data structures
471 */
472extern mempool_t *nfs_rdata_mempool;
473
474static inline struct nfs_read_data *nfs_readdata_alloc(void)
475{
476 struct nfs_read_data *p = mempool_alloc(nfs_rdata_mempool, SLAB_NOFS);
477 if (p)
478 memset(p, 0, sizeof(*p));
479 return p;
480}
481
482static inline void nfs_readdata_free(struct nfs_read_data *p)
483{
484 mempool_free(p, nfs_rdata_mempool);
485}
486
487extern void nfs_readdata_release(struct rpc_task *task);
488
489/*
Andreas Gruenbacherb7fa0552005-06-22 17:16:27 +0000490 * linux/fs/nfs3proc.c
491 */
492#ifdef CONFIG_NFS_V3_ACL
493extern struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type);
494extern int nfs3_proc_setacl(struct inode *inode, int type,
495 struct posix_acl *acl);
Andreas Gruenbacher055ffbe2005-06-22 17:16:27 +0000496extern int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
497 mode_t mode);
Andreas Gruenbacher5c6a9f72005-06-22 17:16:27 +0000498extern void nfs3_forget_cached_acls(struct inode *inode);
Andreas Gruenbacher055ffbe2005-06-22 17:16:27 +0000499#else
500static inline int nfs3_proc_set_default_acl(struct inode *dir,
501 struct inode *inode,
502 mode_t mode)
503{
504 return 0;
505}
Andreas Gruenbacher5c6a9f72005-06-22 17:16:27 +0000506
507static inline void nfs3_forget_cached_acls(struct inode *inode)
508{
509}
Andreas Gruenbacherb7fa0552005-06-22 17:16:27 +0000510#endif /* CONFIG_NFS_V3_ACL */
511
512/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 * linux/fs/mount_clnt.c
514 * (Used only by nfsroot module)
515 */
516extern int nfsroot_mount(struct sockaddr_in *, char *, struct nfs_fh *,
517 int, int);
518
519/*
520 * inline functions
521 */
522
523static inline loff_t
524nfs_size_to_loff_t(__u64 size)
525{
526 loff_t maxsz = (((loff_t) ULONG_MAX) << PAGE_CACHE_SHIFT) + PAGE_CACHE_SIZE - 1;
527 if (size > maxsz)
528 return maxsz;
529 return (loff_t) size;
530}
531
532static inline ino_t
533nfs_fileid_to_ino_t(u64 fileid)
534{
535 ino_t ino = (ino_t) fileid;
536 if (sizeof(ino_t) < sizeof(u64))
537 ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;
538 return ino;
539}
540
541/* NFS root */
542
543extern void * nfs_root_data(void);
544
545#define nfs_wait_event(clnt, wq, condition) \
546({ \
547 int __retval = 0; \
548 if (clnt->cl_intr) { \
549 sigset_t oldmask; \
550 rpc_clnt_sigmask(clnt, &oldmask); \
551 __retval = wait_event_interruptible(wq, condition); \
552 rpc_clnt_sigunmask(clnt, &oldmask); \
553 } else \
554 wait_event(wq, condition); \
555 __retval; \
556})
557
558#define NFS_JUKEBOX_RETRY_TIME (5 * HZ)
559
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560#endif /* __KERNEL__ */
561
562/*
563 * NFS debug flags
564 */
565#define NFSDBG_VFS 0x0001
566#define NFSDBG_DIRCACHE 0x0002
567#define NFSDBG_LOOKUPCACHE 0x0004
568#define NFSDBG_PAGECACHE 0x0008
569#define NFSDBG_PROC 0x0010
570#define NFSDBG_XDR 0x0020
571#define NFSDBG_FILE 0x0040
572#define NFSDBG_ROOT 0x0080
573#define NFSDBG_CALLBACK 0x0100
574#define NFSDBG_ALL 0xFFFF
575
576#ifdef __KERNEL__
577# undef ifdebug
578# ifdef NFS_DEBUG
579# define ifdebug(fac) if (unlikely(nfs_debug & NFSDBG_##fac))
580# else
581# define ifdebug(fac) if (0)
582# endif
583#endif /* __KERNEL */
584
585#endif