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  #ifdef CONFIG_NFS_FSCACHE
35  #include <linux/netfs.h>
36  #endif
37  
38  #include <linux/nfs.h>
39  #include <linux/nfs2.h>
40  #include <linux/nfs3.h>
41  #include <linux/nfs4.h>
42  #include <linux/nfs_xdr.h>
43  #include <linux/nfs_fs_sb.h>
44  
45  #include <linux/mempool.h>
46  
47  /*
48   * These are the default for number of transports to different server IPs
49   */
50  #define NFS_MAX_TRANSPORTS 16
51  
52  /*
53   * Size of the NFS directory verifier
54   */
55  #define NFS_DIR_VERIFIER_SIZE		2
56  
57  /*
58   * NFSv3/v4 Access mode cache entry
59   */
60  struct nfs_access_entry {
61  	struct rb_node		rb_node;
62  	struct list_head	lru;
63  	kuid_t			fsuid;
64  	kgid_t			fsgid;
65  	struct group_info	*group_info;
66  	u64			timestamp;
67  	__u32			mask;
68  	struct rcu_head		rcu_head;
69  };
70  
71  struct nfs_lock_context {
72  	refcount_t count;
73  	struct list_head list;
74  	struct nfs_open_context *open_context;
75  	fl_owner_t lockowner;
76  	atomic_t io_count;
77  	struct rcu_head	rcu_head;
78  };
79  
80  struct nfs4_state;
81  struct nfs_open_context {
82  	struct nfs_lock_context lock_context;
83  	fl_owner_t flock_owner;
84  	struct dentry *dentry;
85  	const struct cred *cred;
86  	struct rpc_cred __rcu *ll_cred;	/* low-level cred - use to check for expiry */
87  	struct nfs4_state *state;
88  	fmode_t mode;
89  
90  	unsigned long flags;
91  #define NFS_CONTEXT_BAD			(2)
92  #define NFS_CONTEXT_UNLOCK	(3)
93  #define NFS_CONTEXT_FILE_OPEN		(4)
94  	int error;
95  
96  	struct list_head list;
97  	struct nfs4_threshold	*mdsthreshold;
98  	struct rcu_head	rcu_head;
99  };
100  
101  struct nfs_open_dir_context {
102  	struct list_head list;
103  	atomic_t cache_hits;
104  	atomic_t cache_misses;
105  	unsigned long attr_gencount;
106  	__be32	verf[NFS_DIR_VERIFIER_SIZE];
107  	__u64 dir_cookie;
108  	__u64 last_cookie;
109  	pgoff_t page_index;
110  	unsigned int dtsize;
111  	bool force_clear;
112  	bool eof;
113  	struct rcu_head rcu_head;
114  };
115  
116  /*
117   * NFSv4 delegation
118   */
119  struct nfs_delegation;
120  
121  struct posix_acl;
122  
123  struct nfs4_xattr_cache;
124  
125  /*
126   * nfs fs inode data in memory
127   */
128  struct nfs_inode {
129  	/*
130  	 * The 64bit 'inode number'
131  	 */
132  	__u64 fileid;
133  
134  	/*
135  	 * NFS file handle
136  	 */
137  	struct nfs_fh		fh;
138  
139  	/*
140  	 * Various flags
141  	 */
142  	unsigned long		flags;			/* atomic bit ops */
143  	unsigned long		cache_validity;		/* bit mask */
144  
145  	/*
146  	 * read_cache_jiffies is when we started read-caching this inode.
147  	 * attrtimeo is for how long the cached information is assumed
148  	 * to be valid. A successful attribute revalidation doubles
149  	 * attrtimeo (up to acregmax/acdirmax), a failure resets it to
150  	 * acregmin/acdirmin.
151  	 *
152  	 * We need to revalidate the cached attrs for this inode if
153  	 *
154  	 *	jiffies - read_cache_jiffies >= attrtimeo
155  	 *
156  	 * Please note the comparison is greater than or equal
157  	 * so that zero timeout values can be specified.
158  	 */
159  	unsigned long		read_cache_jiffies;
160  	unsigned long		attrtimeo;
161  	unsigned long		attrtimeo_timestamp;
162  
163  	unsigned long		attr_gencount;
164  
165  	struct rb_root		access_cache;
166  	struct list_head	access_cache_entry_lru;
167  	struct list_head	access_cache_inode_lru;
168  
169  	union {
170  		/* Directory */
171  		struct {
172  			/* "Generation counter" for the attribute cache.
173  			 * This is bumped whenever we update the metadata
174  			 * on the server.
175  			 */
176  			unsigned long	cache_change_attribute;
177  			/*
178  			 * This is the cookie verifier used for NFSv3 readdir
179  			 * operations
180  			 */
181  			__be32		cookieverf[NFS_DIR_VERIFIER_SIZE];
182  			/* Readers: in-flight sillydelete RPC calls */
183  			/* Writers: rmdir */
184  			struct rw_semaphore	rmdir_sem;
185  		};
186  		/* Regular file */
187  		struct {
188  			atomic_long_t	nrequests;
189  			atomic_long_t	redirtied_pages;
190  			struct nfs_mds_commit_info commit_info;
191  			struct mutex	commit_mutex;
192  		};
193  	};
194  
195  	/* Open contexts for shared mmap writes */
196  	struct list_head	open_files;
197  
198  	/* Keep track of out-of-order replies.
199  	 * The ooo array contains start/end pairs of
200  	 * numbers from the changeid sequence when
201  	 * the inode's iversion has been updated.
202  	 * It also contains end/start pair (i.e. reverse order)
203  	 * of sections of the changeid sequence that have
204  	 * been seen in replies from the server.
205  	 * Normally these should match and when both
206  	 * A:B and B:A are found in ooo, they are both removed.
207  	 * And if a reply with A:B causes an iversion update
208  	 * of A:B, then neither are added.
209  	 * When a reply has pre_change that doesn't match
210  	 * iversion, then the changeid pair and any consequent
211  	 * change in iversion ARE added.  Later replies
212  	 * might fill in the gaps, or possibly a gap is caused
213  	 * by a change from another client.
214  	 * When a file or directory is opened, if the ooo table
215  	 * is not empty, then we assume the gaps were due to
216  	 * another client and we invalidate the cached data.
217  	 *
218  	 * We can only track a limited number of concurrent gaps.
219  	 * Currently that limit is 16.
220  	 * We allocate the table on demand.  If there is insufficient
221  	 * memory, then we probably cannot cache the file anyway
222  	 * so there is no loss.
223  	 */
224  	struct {
225  		int cnt;
226  		struct {
227  			u64 start, end;
228  		} gap[16];
229  	} *ooo;
230  
231  #if IS_ENABLED(CONFIG_NFS_V4)
232  	struct nfs4_cached_acl	*nfs4_acl;
233          /* NFSv4 state */
234  	struct list_head	open_states;
235  	struct nfs_delegation __rcu *delegation;
236  	struct rw_semaphore	rwsem;
237  
238  	/* pNFS layout information */
239  	struct pnfs_layout_hdr *layout;
240  #endif /* CONFIG_NFS_V4*/
241  	/* how many bytes have been written/read and how many bytes queued up */
242  	__u64 write_io;
243  	__u64 read_io;
244  #ifdef CONFIG_NFS_V4_2
245  	struct nfs4_xattr_cache *xattr_cache;
246  #endif
247  	union {
248  		struct inode		vfs_inode;
249  #ifdef CONFIG_NFS_FSCACHE
250  		struct netfs_inode	netfs; /* netfs context and VFS inode */
251  #endif
252  	};
253  };
254  
255  struct nfs4_copy_state {
256  	struct list_head	copies;
257  	struct list_head	src_copies;
258  	nfs4_stateid		stateid;
259  	struct completion	completion;
260  	uint64_t		count;
261  	struct nfs_writeverf	verf;
262  	int			error;
263  	int			flags;
264  	struct nfs4_state	*parent_src_state;
265  	struct nfs4_state	*parent_dst_state;
266  };
267  
268  /*
269   * Access bit flags
270   */
271  #define NFS_ACCESS_READ        0x0001
272  #define NFS_ACCESS_LOOKUP      0x0002
273  #define NFS_ACCESS_MODIFY      0x0004
274  #define NFS_ACCESS_EXTEND      0x0008
275  #define NFS_ACCESS_DELETE      0x0010
276  #define NFS_ACCESS_EXECUTE     0x0020
277  #define NFS_ACCESS_XAREAD      0x0040
278  #define NFS_ACCESS_XAWRITE     0x0080
279  #define NFS_ACCESS_XALIST      0x0100
280  
281  /*
282   * Cache validity bit flags
283   */
284  #define NFS_INO_INVALID_DATA	BIT(1)		/* cached data is invalid */
285  #define NFS_INO_INVALID_ATIME	BIT(2)		/* cached atime is invalid */
286  #define NFS_INO_INVALID_ACCESS	BIT(3)		/* cached access cred invalid */
287  #define NFS_INO_INVALID_ACL	BIT(4)		/* cached acls are invalid */
288  #define NFS_INO_REVAL_FORCED	BIT(6)		/* force revalidation ignoring a delegation */
289  #define NFS_INO_INVALID_LABEL	BIT(7)		/* cached label is invalid */
290  #define NFS_INO_INVALID_CHANGE	BIT(8)		/* cached change is invalid */
291  #define NFS_INO_INVALID_CTIME	BIT(9)		/* cached ctime is invalid */
292  #define NFS_INO_INVALID_MTIME	BIT(10)		/* cached mtime is invalid */
293  #define NFS_INO_INVALID_SIZE	BIT(11)		/* cached size is invalid */
294  #define NFS_INO_INVALID_OTHER	BIT(12)		/* other attrs are invalid */
295  #define NFS_INO_DATA_INVAL_DEFER	\
296  				BIT(13)		/* Deferred cache invalidation */
297  #define NFS_INO_INVALID_BLOCKS	BIT(14)         /* cached blocks are invalid */
298  #define NFS_INO_INVALID_XATTR	BIT(15)		/* xattrs are invalid */
299  #define NFS_INO_INVALID_NLINK	BIT(16)		/* cached nlinks is invalid */
300  #define NFS_INO_INVALID_MODE	BIT(17)		/* cached mode is invalid */
301  
302  #define NFS_INO_INVALID_ATTR	(NFS_INO_INVALID_CHANGE \
303  		| NFS_INO_INVALID_CTIME \
304  		| NFS_INO_INVALID_MTIME \
305  		| NFS_INO_INVALID_SIZE \
306  		| NFS_INO_INVALID_NLINK \
307  		| NFS_INO_INVALID_MODE \
308  		| NFS_INO_INVALID_OTHER)	/* inode metadata is invalid */
309  
310  /*
311   * Bit offsets in flags field
312   */
313  #define NFS_INO_STALE		(1)		/* possible stale inode */
314  #define NFS_INO_ACL_LRU_SET	(2)		/* Inode is on the LRU list */
315  #define NFS_INO_INVALIDATING	(3)		/* inode is being invalidated */
316  #define NFS_INO_PRESERVE_UNLINKED (4)		/* preserve file if removed while open */
317  #define NFS_INO_LAYOUTCOMMIT	(9)		/* layoutcommit required */
318  #define NFS_INO_LAYOUTCOMMITTING (10)		/* layoutcommit inflight */
319  #define NFS_INO_LAYOUTSTATS	(11)		/* layoutstats inflight */
320  #define NFS_INO_ODIRECT		(12)		/* I/O setting is O_DIRECT */
321  
NFS_I(const struct inode * inode)322  static inline struct nfs_inode *NFS_I(const struct inode *inode)
323  {
324  	return container_of(inode, struct nfs_inode, vfs_inode);
325  }
326  
NFS_SB(const struct super_block * s)327  static inline struct nfs_server *NFS_SB(const struct super_block *s)
328  {
329  	return (struct nfs_server *)(s->s_fs_info);
330  }
331  
NFS_FH(const struct inode * inode)332  static inline struct nfs_fh *NFS_FH(const struct inode *inode)
333  {
334  	return &NFS_I(inode)->fh;
335  }
336  
NFS_SERVER(const struct inode * inode)337  static inline struct nfs_server *NFS_SERVER(const struct inode *inode)
338  {
339  	return NFS_SB(inode->i_sb);
340  }
341  
NFS_CLIENT(const struct inode * inode)342  static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode)
343  {
344  	return NFS_SERVER(inode)->client;
345  }
346  
NFS_PROTO(const struct inode * inode)347  static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode)
348  {
349  	return NFS_SERVER(inode)->nfs_client->rpc_ops;
350  }
351  
NFS_MINATTRTIMEO(const struct inode * inode)352  static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode)
353  {
354  	struct nfs_server *nfss = NFS_SERVER(inode);
355  	return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin;
356  }
357  
NFS_MAXATTRTIMEO(const struct inode * inode)358  static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode)
359  {
360  	struct nfs_server *nfss = NFS_SERVER(inode);
361  	return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax;
362  }
363  
NFS_STALE(const struct inode * inode)364  static inline int NFS_STALE(const struct inode *inode)
365  {
366  	return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
367  }
368  
NFS_FILEID(const struct inode * inode)369  static inline __u64 NFS_FILEID(const struct inode *inode)
370  {
371  	return NFS_I(inode)->fileid;
372  }
373  
set_nfs_fileid(struct inode * inode,__u64 fileid)374  static inline void set_nfs_fileid(struct inode *inode, __u64 fileid)
375  {
376  	NFS_I(inode)->fileid = fileid;
377  }
378  
nfs_mark_for_revalidate(struct inode * inode)379  static inline void nfs_mark_for_revalidate(struct inode *inode)
380  {
381  	struct nfs_inode *nfsi = NFS_I(inode);
382  
383  	spin_lock(&inode->i_lock);
384  	nfsi->cache_validity |= NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL |
385  				NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME |
386  				NFS_INO_INVALID_SIZE;
387  	if (S_ISDIR(inode->i_mode))
388  		nfsi->cache_validity |= NFS_INO_INVALID_DATA;
389  	spin_unlock(&inode->i_lock);
390  }
391  
nfs_server_capable(const struct inode * inode,int cap)392  static inline int nfs_server_capable(const struct inode *inode, int cap)
393  {
394  	return NFS_SERVER(inode)->caps & cap;
395  }
396  
397  /**
398   * nfs_save_change_attribute - Returns the inode attribute change cookie
399   * @dir - pointer to parent directory inode
400   * The "cache change attribute" is updated when we need to revalidate
401   * our dentry cache after a directory was seen to change on the server.
402   */
nfs_save_change_attribute(struct inode * dir)403  static inline unsigned long nfs_save_change_attribute(struct inode *dir)
404  {
405  	return NFS_I(dir)->cache_change_attribute;
406  }
407  
408  /*
409   * linux/fs/nfs/inode.c
410   */
411  extern int nfs_sync_mapping(struct address_space *mapping);
412  extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping);
413  extern void nfs_zap_caches(struct inode *);
414  extern void nfs_set_inode_stale(struct inode *inode);
415  extern void nfs_invalidate_atime(struct inode *);
416  extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
417  				struct nfs_fattr *);
418  struct inode *nfs_ilookup(struct super_block *sb, struct nfs_fattr *, struct nfs_fh *);
419  extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
420  extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
421  extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
422  extern int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr);
423  extern int nfs_getattr(struct mnt_idmap *, const struct path *,
424  		       struct kstat *, u32, unsigned int);
425  extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *, const struct cred *);
426  extern void nfs_access_set_mask(struct nfs_access_entry *, u32);
427  extern int nfs_permission(struct mnt_idmap *, struct inode *, int);
428  extern int nfs_open(struct inode *, struct file *);
429  extern int nfs_attribute_cache_expired(struct inode *inode);
430  extern int nfs_revalidate_inode(struct inode *inode, unsigned long flags);
431  extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
432  extern int nfs_clear_invalid_mapping(struct address_space *mapping);
433  extern bool nfs_mapping_need_revalidate_inode(struct inode *inode);
434  extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
435  extern int nfs_revalidate_mapping_rcu(struct inode *inode);
436  extern int nfs_setattr(struct mnt_idmap *, struct dentry *, struct iattr *);
437  extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *);
438  extern void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr);
439  extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
440  extern void put_nfs_open_context(struct nfs_open_context *ctx);
441  extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode);
442  extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode, struct file *filp);
443  extern void nfs_inode_attach_open_context(struct nfs_open_context *ctx);
444  extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);
445  extern void nfs_file_clear_open_context(struct file *flip);
446  extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx);
447  extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx);
448  extern u64 nfs_compat_user_ino64(u64 fileid);
449  extern void nfs_fattr_init(struct nfs_fattr *fattr);
450  extern void nfs_fattr_set_barrier(struct nfs_fattr *fattr);
451  extern unsigned long nfs_inc_attr_generation_counter(void);
452  
453  extern struct nfs_fattr *nfs_alloc_fattr(void);
454  extern struct nfs_fattr *nfs_alloc_fattr_with_label(struct nfs_server *server);
455  
nfs4_label_free(struct nfs4_label * label)456  static inline void nfs4_label_free(struct nfs4_label *label)
457  {
458  #ifdef CONFIG_NFS_V4_SECURITY_LABEL
459  	if (label) {
460  		kfree(label->label);
461  		kfree(label);
462  	}
463  #endif
464  }
465  
nfs_free_fattr(const struct nfs_fattr * fattr)466  static inline void nfs_free_fattr(const struct nfs_fattr *fattr)
467  {
468  	if (fattr)
469  		nfs4_label_free(fattr->label);
470  	kfree(fattr);
471  }
472  
473  extern struct nfs_fh *nfs_alloc_fhandle(void);
474  
nfs_free_fhandle(const struct nfs_fh * fh)475  static inline void nfs_free_fhandle(const struct nfs_fh *fh)
476  {
477  	kfree(fh);
478  }
479  
480  #ifdef NFS_DEBUG
481  extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh);
nfs_display_fhandle_hash(const struct nfs_fh * fh)482  static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
483  {
484  	return _nfs_display_fhandle_hash(fh);
485  }
486  extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption);
487  #define nfs_display_fhandle(fh, caption)			\
488  	do {							\
489  		if (unlikely(nfs_debug & NFSDBG_FACILITY))	\
490  			_nfs_display_fhandle(fh, caption);	\
491  	} while (0)
492  #else
nfs_display_fhandle_hash(const struct nfs_fh * fh)493  static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
494  {
495  	return 0;
496  }
nfs_display_fhandle(const struct nfs_fh * fh,const char * caption)497  static inline void nfs_display_fhandle(const struct nfs_fh *fh,
498  				       const char *caption)
499  {
500  }
501  #endif
502  
503  /*
504   * linux/fs/nfs/nfsroot.c
505   */
506  extern int  nfs_root_data(char **root_device, char **root_data); /*__init*/
507  /* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
508  extern __be32 root_nfs_parse_addr(char *name); /*__init*/
509  
510  /*
511   * linux/fs/nfs/file.c
512   */
513  extern const struct file_operations nfs_file_operations;
514  #if IS_ENABLED(CONFIG_NFS_V4)
515  extern const struct file_operations nfs4_file_operations;
516  #endif /* CONFIG_NFS_V4 */
517  extern const struct address_space_operations nfs_file_aops;
518  extern const struct address_space_operations nfs_dir_aops;
519  
nfs_file_open_context(struct file * filp)520  static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
521  {
522  	return filp->private_data;
523  }
524  
nfs_file_cred(struct file * file)525  static inline const struct cred *nfs_file_cred(struct file *file)
526  {
527  	if (file != NULL) {
528  		struct nfs_open_context *ctx =
529  			nfs_file_open_context(file);
530  		if (ctx)
531  			return ctx->cred;
532  	}
533  	return NULL;
534  }
535  
536  /*
537   * linux/fs/nfs/direct.c
538   */
539  int nfs_swap_rw(struct kiocb *iocb, struct iov_iter *iter);
540  ssize_t nfs_file_direct_read(struct kiocb *iocb,
541  			     struct iov_iter *iter, bool swap);
542  ssize_t nfs_file_direct_write(struct kiocb *iocb,
543  			      struct iov_iter *iter, bool swap);
544  
545  /*
546   * linux/fs/nfs/dir.c
547   */
548  extern const struct file_operations nfs_dir_operations;
549  extern const struct dentry_operations nfs_dentry_operations;
550  
551  extern void nfs_force_lookup_revalidate(struct inode *dir);
552  extern void nfs_set_verifier(struct dentry * dentry, unsigned long verf);
553  #if IS_ENABLED(CONFIG_NFS_V4)
554  extern void nfs_clear_verifier_delegated(struct inode *inode);
555  #endif /* IS_ENABLED(CONFIG_NFS_V4) */
556  extern struct dentry *nfs_add_or_obtain(struct dentry *dentry,
557  			struct nfs_fh *fh, struct nfs_fattr *fattr);
558  extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh,
559  			struct nfs_fattr *fattr);
560  extern int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags);
561  extern void nfs_access_zap_cache(struct inode *inode);
562  extern int nfs_access_get_cached(struct inode *inode, const struct cred *cred,
563  				 u32 *mask, bool may_block);
564  extern int nfs_atomic_open_v23(struct inode *dir, struct dentry *dentry,
565  			       struct file *file, unsigned int open_flags,
566  			       umode_t mode);
567  
568  /*
569   * linux/fs/nfs/symlink.c
570   */
571  extern const struct inode_operations nfs_symlink_inode_operations;
572  
573  /*
574   * linux/fs/nfs/sysctl.c
575   */
576  #ifdef CONFIG_SYSCTL
577  extern int nfs_register_sysctl(void);
578  extern void nfs_unregister_sysctl(void);
579  #else
580  #define nfs_register_sysctl() 0
581  #define nfs_unregister_sysctl() do { } while(0)
582  #endif
583  
584  /*
585   * linux/fs/nfs/namespace.c
586   */
587  extern const struct inode_operations nfs_mountpoint_inode_operations;
588  extern const struct inode_operations nfs_referral_inode_operations;
589  extern int nfs_mountpoint_expiry_timeout;
590  extern void nfs_release_automount_timer(void);
591  
592  /*
593   * linux/fs/nfs/unlink.c
594   */
595  extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);
596  
597  /*
598   * linux/fs/nfs/write.c
599   */
600  extern int  nfs_congestion_kb;
601  extern int  nfs_writepages(struct address_space *, struct writeback_control *);
602  extern int  nfs_flush_incompatible(struct file *file, struct folio *folio);
603  extern int  nfs_update_folio(struct file *file, struct folio *folio,
604  			     unsigned int offset, unsigned int count);
605  
606  /*
607   * Try to write back everything synchronously (but check the
608   * return value!)
609   */
610  extern int nfs_sync_inode(struct inode *inode);
611  extern int nfs_wb_all(struct inode *inode);
612  extern int nfs_wb_folio(struct inode *inode, struct folio *folio);
613  int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio);
614  extern int  nfs_commit_inode(struct inode *, int);
615  extern struct nfs_commit_data *nfs_commitdata_alloc(void);
616  extern void nfs_commit_free(struct nfs_commit_data *data);
617  void nfs_commit_begin(struct nfs_mds_commit_info *cinfo);
618  bool nfs_commit_end(struct nfs_mds_commit_info *cinfo);
619  
nfs_have_writebacks(const struct inode * inode)620  static inline bool nfs_have_writebacks(const struct inode *inode)
621  {
622  	if (S_ISREG(inode->i_mode))
623  		return atomic_long_read(&NFS_I(inode)->nrequests) != 0;
624  	return false;
625  }
626  
627  /*
628   * linux/fs/nfs/read.c
629   */
630  int  nfs_read_folio(struct file *, struct folio *);
631  void nfs_readahead(struct readahead_control *);
632  
633  /*
634   * inline functions
635   */
636  
nfs_size_to_loff_t(__u64 size)637  static inline loff_t nfs_size_to_loff_t(__u64 size)
638  {
639  	return min_t(u64, size, OFFSET_MAX);
640  }
641  
642  static inline ino_t
nfs_fileid_to_ino_t(u64 fileid)643  nfs_fileid_to_ino_t(u64 fileid)
644  {
645  	ino_t ino = (ino_t) fileid;
646  	if (sizeof(ino_t) < sizeof(u64))
647  		ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;
648  	return ino;
649  }
650  
nfs_ooo_clear(struct nfs_inode * nfsi)651  static inline void nfs_ooo_clear(struct nfs_inode *nfsi)
652  {
653  	nfsi->cache_validity &= ~NFS_INO_DATA_INVAL_DEFER;
654  	kfree(nfsi->ooo);
655  	nfsi->ooo = NULL;
656  }
657  
nfs_ooo_test(struct nfs_inode * nfsi)658  static inline bool nfs_ooo_test(struct nfs_inode *nfsi)
659  {
660  	return (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER) ||
661  		(nfsi->ooo && nfsi->ooo->cnt > 0);
662  
663  }
664  
665  #define NFS_JUKEBOX_RETRY_TIME (5 * HZ)
666  
667  /* We need to block new opens while a file is being unlinked.
668   * If it is opened *before* we decide to unlink, we will silly-rename
669   * instead. If it is opened *after*, then we need to create or will fail.
670   * If we allow the two to race, we could end up with a file that is open
671   * but deleted on the server resulting in ESTALE.
672   * So use ->d_fsdata to record when the unlink is happening
673   * and block dentry revalidation while it is set.
674   */
675  #define NFS_FSDATA_BLOCKED ((void*)1)
676  
677  # undef ifdebug
678  # ifdef NFS_DEBUG
679  #  define ifdebug(fac)		if (unlikely(nfs_debug & NFSDBG_##fac))
680  #  define NFS_IFDEBUG(x)	x
681  # else
682  #  define ifdebug(fac)		if (0)
683  #  define NFS_IFDEBUG(x)
684  # endif
685  #endif
686