xref: /openbmc/linux/fs/nfs/internal.h (revision 5bd8e16d)
1 /*
2  * NFS internal definitions
3  */
4 
5 #include "nfs4_fs.h"
6 #include <linux/mount.h>
7 #include <linux/security.h>
8 #include <linux/crc32.h>
9 
10 #define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
11 
12 struct nfs_string;
13 
14 /* Maximum number of readahead requests
15  * FIXME: this should really be a sysctl so that users may tune it to suit
16  *        their needs. People that do NFS over a slow network, might for
17  *        instance want to reduce it to something closer to 1 for improved
18  *        interactive response.
19  */
20 #define NFS_MAX_READAHEAD	(RPC_DEF_SLOT_TABLE - 1)
21 
22 static inline void nfs_attr_check_mountpoint(struct super_block *parent, struct nfs_fattr *fattr)
23 {
24 	if (!nfs_fsid_equal(&NFS_SB(parent)->fsid, &fattr->fsid))
25 		fattr->valid |= NFS_ATTR_FATTR_MOUNTPOINT;
26 }
27 
28 static inline int nfs_attr_use_mounted_on_fileid(struct nfs_fattr *fattr)
29 {
30 	if (((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) == 0) ||
31 	    (((fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT) == 0) &&
32 	     ((fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) == 0)))
33 		return 0;
34 
35 	fattr->fileid = fattr->mounted_on_fileid;
36 	return 1;
37 }
38 
39 struct nfs_clone_mount {
40 	const struct super_block *sb;
41 	const struct dentry *dentry;
42 	struct nfs_fh *fh;
43 	struct nfs_fattr *fattr;
44 	char *hostname;
45 	char *mnt_path;
46 	struct sockaddr *addr;
47 	size_t addrlen;
48 	rpc_authflavor_t authflavor;
49 };
50 
51 /*
52  * Note: RFC 1813 doesn't limit the number of auth flavors that
53  * a server can return, so make something up.
54  */
55 #define NFS_MAX_SECFLAVORS	(12)
56 
57 /*
58  * Value used if the user did not specify a port value.
59  */
60 #define NFS_UNSPEC_PORT		(-1)
61 
62 /*
63  * Maximum number of pages that readdir can use for creating
64  * a vmapped array of pages.
65  */
66 #define NFS_MAX_READDIR_PAGES 8
67 
68 struct nfs_client_initdata {
69 	unsigned long init_flags;
70 	const char *hostname;
71 	const struct sockaddr *addr;
72 	size_t addrlen;
73 	struct nfs_subversion *nfs_mod;
74 	int proto;
75 	u32 minorversion;
76 	struct net *net;
77 };
78 
79 /*
80  * In-kernel mount arguments
81  */
82 struct nfs_parsed_mount_data {
83 	int			flags;
84 	unsigned int		rsize, wsize;
85 	unsigned int		timeo, retrans;
86 	unsigned int		acregmin, acregmax,
87 				acdirmin, acdirmax;
88 	unsigned int		namlen;
89 	unsigned int		options;
90 	unsigned int		bsize;
91 	unsigned int		auth_flavor_len;
92 	rpc_authflavor_t	auth_flavors[1];
93 	char			*client_address;
94 	unsigned int		version;
95 	unsigned int		minorversion;
96 	char			*fscache_uniq;
97 	bool			need_mount;
98 
99 	struct {
100 		struct sockaddr_storage	address;
101 		size_t			addrlen;
102 		char			*hostname;
103 		u32			version;
104 		int			port;
105 		unsigned short		protocol;
106 	} mount_server;
107 
108 	struct {
109 		struct sockaddr_storage	address;
110 		size_t			addrlen;
111 		char			*hostname;
112 		char			*export_path;
113 		int			port;
114 		unsigned short		protocol;
115 	} nfs_server;
116 
117 	struct security_mnt_opts lsm_opts;
118 	struct net		*net;
119 };
120 
121 /* mount_clnt.c */
122 struct nfs_mount_request {
123 	struct sockaddr		*sap;
124 	size_t			salen;
125 	char			*hostname;
126 	char			*dirpath;
127 	u32			version;
128 	unsigned short		protocol;
129 	struct nfs_fh		*fh;
130 	int			noresvport;
131 	unsigned int		*auth_flav_len;
132 	rpc_authflavor_t	*auth_flavs;
133 	struct net		*net;
134 };
135 
136 struct nfs_mount_info {
137 	void (*fill_super)(struct super_block *, struct nfs_mount_info *);
138 	int (*set_security)(struct super_block *, struct dentry *, struct nfs_mount_info *);
139 	struct nfs_parsed_mount_data *parsed;
140 	struct nfs_clone_mount *cloned;
141 	struct nfs_fh *mntfh;
142 };
143 
144 extern int nfs_mount(struct nfs_mount_request *info);
145 extern void nfs_umount(const struct nfs_mount_request *info);
146 
147 /* client.c */
148 extern const struct rpc_program nfs_program;
149 extern void nfs_clients_init(struct net *net);
150 extern struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *);
151 int nfs_create_rpc_client(struct nfs_client *, const struct rpc_timeout *, rpc_authflavor_t);
152 struct nfs_client *nfs_get_client(const struct nfs_client_initdata *,
153 				  const struct rpc_timeout *, const char *,
154 				  rpc_authflavor_t);
155 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *, struct nfs_fattr *);
156 void nfs_server_insert_lists(struct nfs_server *);
157 void nfs_init_timeout_values(struct rpc_timeout *, int, unsigned int, unsigned int);
158 int nfs_init_server_rpcclient(struct nfs_server *, const struct rpc_timeout *t,
159 		rpc_authflavor_t);
160 struct nfs_server *nfs_alloc_server(void);
161 void nfs_server_copy_userdata(struct nfs_server *, struct nfs_server *);
162 
163 extern void nfs_cleanup_cb_ident_idr(struct net *);
164 extern void nfs_put_client(struct nfs_client *);
165 extern void nfs_free_client(struct nfs_client *);
166 extern struct nfs_client *nfs4_find_client_ident(struct net *, int);
167 extern struct nfs_client *
168 nfs4_find_client_sessionid(struct net *, const struct sockaddr *,
169 				struct nfs4_sessionid *, u32);
170 extern struct nfs_server *nfs_create_server(struct nfs_mount_info *,
171 					struct nfs_subversion *);
172 extern struct nfs_server *nfs4_create_server(
173 					struct nfs_mount_info *,
174 					struct nfs_subversion *);
175 extern struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *,
176 						      struct nfs_fh *);
177 extern void nfs_free_server(struct nfs_server *server);
178 extern struct nfs_server *nfs_clone_server(struct nfs_server *,
179 					   struct nfs_fh *,
180 					   struct nfs_fattr *,
181 					   rpc_authflavor_t);
182 extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
183 extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
184 extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
185 					     const struct sockaddr *ds_addr,
186 					     int ds_addrlen, int ds_proto,
187 					     unsigned int ds_timeo,
188 					     unsigned int ds_retrans);
189 extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
190 						struct inode *);
191 #ifdef CONFIG_PROC_FS
192 extern int __init nfs_fs_proc_init(void);
193 extern void nfs_fs_proc_exit(void);
194 #else
195 static inline int nfs_fs_proc_init(void)
196 {
197 	return 0;
198 }
199 static inline void nfs_fs_proc_exit(void)
200 {
201 }
202 #endif
203 
204 #ifdef CONFIG_NFS_V4_1
205 int nfs_sockaddr_match_ipaddr(const struct sockaddr *, const struct sockaddr *);
206 #endif
207 
208 /* nfs3client.c */
209 #if IS_ENABLED(CONFIG_NFS_V3)
210 struct nfs_server *nfs3_create_server(struct nfs_mount_info *, struct nfs_subversion *);
211 struct nfs_server *nfs3_clone_server(struct nfs_server *, struct nfs_fh *,
212 				     struct nfs_fattr *, rpc_authflavor_t);
213 #endif
214 
215 /* callback_xdr.c */
216 extern struct svc_version nfs4_callback_version1;
217 extern struct svc_version nfs4_callback_version4;
218 
219 struct nfs_pageio_descriptor;
220 /* pagelist.c */
221 extern int __init nfs_init_nfspagecache(void);
222 extern void nfs_destroy_nfspagecache(void);
223 extern int __init nfs_init_readpagecache(void);
224 extern void nfs_destroy_readpagecache(void);
225 extern int __init nfs_init_writepagecache(void);
226 extern void nfs_destroy_writepagecache(void);
227 
228 extern int __init nfs_init_directcache(void);
229 extern void nfs_destroy_directcache(void);
230 extern bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount);
231 extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
232 			      struct nfs_pgio_header *hdr,
233 			      void (*release)(struct nfs_pgio_header *hdr));
234 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
235 int nfs_iocounter_wait(struct nfs_io_counter *c);
236 
237 static inline void nfs_iocounter_init(struct nfs_io_counter *c)
238 {
239 	c->flags = 0;
240 	atomic_set(&c->io_count, 0);
241 }
242 
243 /* nfs2xdr.c */
244 extern struct rpc_procinfo nfs_procedures[];
245 extern int nfs2_decode_dirent(struct xdr_stream *,
246 				struct nfs_entry *, int);
247 
248 /* nfs3xdr.c */
249 extern struct rpc_procinfo nfs3_procedures[];
250 extern int nfs3_decode_dirent(struct xdr_stream *,
251 				struct nfs_entry *, int);
252 
253 /* nfs4xdr.c */
254 #if IS_ENABLED(CONFIG_NFS_V4)
255 extern int nfs4_decode_dirent(struct xdr_stream *,
256 				struct nfs_entry *, int);
257 #endif
258 #ifdef CONFIG_NFS_V4_1
259 extern const u32 nfs41_maxread_overhead;
260 extern const u32 nfs41_maxwrite_overhead;
261 extern const u32 nfs41_maxgetdevinfo_overhead;
262 #endif
263 
264 /* nfs4proc.c */
265 #if IS_ENABLED(CONFIG_NFS_V4)
266 extern struct rpc_procinfo nfs4_procedures[];
267 #endif
268 
269 /* proc.c */
270 void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
271 extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
272 			   const struct rpc_timeout *timeparms,
273 			   const char *ip_addr);
274 
275 /* dir.c */
276 extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
277 					    struct shrink_control *sc);
278 extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
279 					   struct shrink_control *sc);
280 struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
281 int nfs_create(struct inode *, struct dentry *, umode_t, bool);
282 int nfs_mkdir(struct inode *, struct dentry *, umode_t);
283 int nfs_rmdir(struct inode *, struct dentry *);
284 int nfs_unlink(struct inode *, struct dentry *);
285 int nfs_symlink(struct inode *, struct dentry *, const char *);
286 int nfs_link(struct dentry *, struct inode *, struct dentry *);
287 int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
288 int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
289 
290 /* file.c */
291 int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
292 loff_t nfs_file_llseek(struct file *, loff_t, int);
293 int nfs_file_flush(struct file *, fl_owner_t);
294 ssize_t nfs_file_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
295 ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
296 			     size_t, unsigned int);
297 int nfs_file_mmap(struct file *, struct vm_area_struct *);
298 ssize_t nfs_file_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
299 int nfs_file_release(struct inode *, struct file *);
300 int nfs_lock(struct file *, int, struct file_lock *);
301 int nfs_flock(struct file *, int, struct file_lock *);
302 ssize_t nfs_file_splice_write(struct pipe_inode_info *, struct file *, loff_t *,
303 			      size_t, unsigned int);
304 int nfs_check_flags(int);
305 int nfs_setlease(struct file *, long, struct file_lock **);
306 
307 /* inode.c */
308 extern struct workqueue_struct *nfsiod_workqueue;
309 extern struct inode *nfs_alloc_inode(struct super_block *sb);
310 extern void nfs_destroy_inode(struct inode *);
311 extern int nfs_write_inode(struct inode *, struct writeback_control *);
312 extern int nfs_drop_inode(struct inode *);
313 extern void nfs_clear_inode(struct inode *);
314 extern void nfs_evict_inode(struct inode *);
315 void nfs_zap_acl_cache(struct inode *inode);
316 extern int nfs_wait_bit_killable(void *word);
317 
318 /* super.c */
319 extern const struct super_operations nfs_sops;
320 extern struct file_system_type nfs_fs_type;
321 extern struct file_system_type nfs_xdev_fs_type;
322 #if IS_ENABLED(CONFIG_NFS_V4)
323 extern struct file_system_type nfs4_xdev_fs_type;
324 extern struct file_system_type nfs4_referral_fs_type;
325 #endif
326 struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
327 			struct nfs_subversion *);
328 void nfs_initialise_sb(struct super_block *);
329 int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
330 int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
331 struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
332 				   struct nfs_mount_info *, struct nfs_subversion *);
333 struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
334 struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
335 		const char *, struct nfs_mount_info *);
336 void nfs_kill_super(struct super_block *);
337 void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
338 
339 extern struct rpc_stat nfs_rpcstat;
340 
341 extern int __init register_nfs_fs(void);
342 extern void __exit unregister_nfs_fs(void);
343 extern void nfs_sb_active(struct super_block *sb);
344 extern void nfs_sb_deactive(struct super_block *sb);
345 
346 /* namespace.c */
347 #define NFS_PATH_CANONICAL 1
348 extern char *nfs_path(char **p, struct dentry *dentry,
349 		      char *buffer, ssize_t buflen, unsigned flags);
350 extern struct vfsmount *nfs_d_automount(struct path *path);
351 struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
352 			      struct nfs_fh *, struct nfs_fattr *);
353 struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
354 				 struct nfs_fattr *, rpc_authflavor_t);
355 
356 /* getroot.c */
357 extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
358 				   const char *);
359 #if IS_ENABLED(CONFIG_NFS_V4)
360 extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
361 				    const char *);
362 
363 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool);
364 #endif
365 
366 struct nfs_pgio_completion_ops;
367 /* read.c */
368 extern struct nfs_read_header *nfs_readhdr_alloc(void);
369 extern void nfs_readhdr_free(struct nfs_pgio_header *hdr);
370 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
371 			struct inode *inode,
372 			const struct nfs_pgio_completion_ops *compl_ops);
373 extern int nfs_initiate_read(struct rpc_clnt *clnt,
374 			     struct nfs_read_data *data,
375 			     const struct rpc_call_ops *call_ops, int flags);
376 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
377 extern int nfs_generic_pagein(struct nfs_pageio_descriptor *desc,
378 			      struct nfs_pgio_header *hdr);
379 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
380 extern void nfs_readdata_release(struct nfs_read_data *rdata);
381 
382 /* super.c */
383 void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
384 void nfs_umount_begin(struct super_block *);
385 int  nfs_statfs(struct dentry *, struct kstatfs *);
386 int  nfs_show_options(struct seq_file *, struct dentry *);
387 int  nfs_show_devname(struct seq_file *, struct dentry *);
388 int  nfs_show_path(struct seq_file *, struct dentry *);
389 int  nfs_show_stats(struct seq_file *, struct dentry *);
390 void nfs_put_super(struct super_block *);
391 int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
392 
393 /* write.c */
394 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
395 			struct inode *inode, int ioflags,
396 			const struct nfs_pgio_completion_ops *compl_ops);
397 extern struct nfs_write_header *nfs_writehdr_alloc(void);
398 extern void nfs_writehdr_free(struct nfs_pgio_header *hdr);
399 extern int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
400 			     struct nfs_pgio_header *hdr);
401 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
402 extern void nfs_writedata_release(struct nfs_write_data *wdata);
403 extern void nfs_commit_free(struct nfs_commit_data *p);
404 extern int nfs_initiate_write(struct rpc_clnt *clnt,
405 			      struct nfs_write_data *data,
406 			      const struct rpc_call_ops *call_ops,
407 			      int how, int flags);
408 extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
409 extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
410 extern int nfs_initiate_commit(struct rpc_clnt *clnt,
411 			       struct nfs_commit_data *data,
412 			       const struct rpc_call_ops *call_ops,
413 			       int how, int flags);
414 extern void nfs_init_commit(struct nfs_commit_data *data,
415 			    struct list_head *head,
416 			    struct pnfs_layout_segment *lseg,
417 			    struct nfs_commit_info *cinfo);
418 int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
419 			 struct nfs_commit_info *cinfo, int max);
420 int nfs_scan_commit(struct inode *inode, struct list_head *dst,
421 		    struct nfs_commit_info *cinfo);
422 void nfs_mark_request_commit(struct nfs_page *req,
423 			     struct pnfs_layout_segment *lseg,
424 			     struct nfs_commit_info *cinfo);
425 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
426 			    int how, struct nfs_commit_info *cinfo);
427 void nfs_retry_commit(struct list_head *page_list,
428 		      struct pnfs_layout_segment *lseg,
429 		      struct nfs_commit_info *cinfo);
430 void nfs_commitdata_release(struct nfs_commit_data *data);
431 void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
432 				 struct nfs_commit_info *cinfo);
433 void nfs_request_remove_commit_list(struct nfs_page *req,
434 				    struct nfs_commit_info *cinfo);
435 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
436 		    struct inode *inode,
437 		    struct nfs_direct_req *dreq);
438 int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
439 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
440 
441 #ifdef CONFIG_MIGRATION
442 extern int nfs_migrate_page(struct address_space *,
443 		struct page *, struct page *, enum migrate_mode);
444 #else
445 #define nfs_migrate_page NULL
446 #endif
447 
448 /* direct.c */
449 void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
450 			      struct nfs_direct_req *dreq);
451 static inline void nfs_inode_dio_wait(struct inode *inode)
452 {
453 	inode_dio_wait(inode);
454 }
455 extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
456 
457 /* nfs4proc.c */
458 extern void __nfs4_read_done_cb(struct nfs_read_data *);
459 extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
460 			    const struct rpc_timeout *timeparms,
461 			    const char *ip_addr);
462 extern int nfs40_walk_client_list(struct nfs_client *clp,
463 				struct nfs_client **result,
464 				struct rpc_cred *cred);
465 extern int nfs41_walk_client_list(struct nfs_client *clp,
466 				struct nfs_client **result,
467 				struct rpc_cred *cred);
468 
469 /*
470  * Determine the device name as a string
471  */
472 static inline char *nfs_devname(struct dentry *dentry,
473 				char *buffer, ssize_t buflen)
474 {
475 	char *dummy;
476 	return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
477 }
478 
479 /*
480  * Determine the actual block size (and log2 thereof)
481  */
482 static inline
483 unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
484 {
485 	/* make sure blocksize is a power of two */
486 	if ((bsize & (bsize - 1)) || nrbitsp) {
487 		unsigned char	nrbits;
488 
489 		for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
490 			;
491 		bsize = 1 << nrbits;
492 		if (nrbitsp)
493 			*nrbitsp = nrbits;
494 	}
495 
496 	return bsize;
497 }
498 
499 /*
500  * Calculate the number of 512byte blocks used.
501  */
502 static inline blkcnt_t nfs_calc_block_size(u64 tsize)
503 {
504 	blkcnt_t used = (tsize + 511) >> 9;
505 	return (used > ULONG_MAX) ? ULONG_MAX : used;
506 }
507 
508 /*
509  * Compute and set NFS server blocksize
510  */
511 static inline
512 unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
513 {
514 	if (bsize < NFS_MIN_FILE_IO_SIZE)
515 		bsize = NFS_DEF_FILE_IO_SIZE;
516 	else if (bsize >= NFS_MAX_FILE_IO_SIZE)
517 		bsize = NFS_MAX_FILE_IO_SIZE;
518 
519 	return nfs_block_bits(bsize, nrbitsp);
520 }
521 
522 /*
523  * Determine the maximum file size for a superblock
524  */
525 static inline
526 void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
527 {
528 	sb->s_maxbytes = (loff_t)maxfilesize;
529 	if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
530 		sb->s_maxbytes = MAX_LFS_FILESIZE;
531 }
532 
533 /*
534  * Determine the number of bytes of data the page contains
535  */
536 static inline
537 unsigned int nfs_page_length(struct page *page)
538 {
539 	loff_t i_size = i_size_read(page_file_mapping(page)->host);
540 
541 	if (i_size > 0) {
542 		pgoff_t page_index = page_file_index(page);
543 		pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
544 		if (page_index < end_index)
545 			return PAGE_CACHE_SIZE;
546 		if (page_index == end_index)
547 			return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
548 	}
549 	return 0;
550 }
551 
552 /*
553  * Convert a umode to a dirent->d_type
554  */
555 static inline
556 unsigned char nfs_umode_to_dtype(umode_t mode)
557 {
558 	return (mode >> 12) & 15;
559 }
560 
561 /*
562  * Determine the number of pages in an array of length 'len' and
563  * with a base offset of 'base'
564  */
565 static inline
566 unsigned int nfs_page_array_len(unsigned int base, size_t len)
567 {
568 	return ((unsigned long)len + (unsigned long)base +
569 		PAGE_SIZE - 1) >> PAGE_SHIFT;
570 }
571 
572 /*
573  * Convert a struct timespec into a 64-bit change attribute
574  *
575  * This does approximately the same thing as timespec_to_ns(),
576  * but for calculation efficiency, we multiply the seconds by
577  * 1024*1024*1024.
578  */
579 static inline
580 u64 nfs_timespec_to_change_attr(const struct timespec *ts)
581 {
582 	return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
583 }
584 
585 #ifdef CONFIG_CRC32
586 /**
587  * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
588  * @fh - pointer to filehandle
589  *
590  * returns a crc32 hash for the filehandle that is compatible with
591  * the one displayed by "wireshark".
592  */
593 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
594 {
595 	return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
596 }
597 #else
598 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
599 {
600 	return 0;
601 }
602 #endif
603