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