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