xref: /openbmc/linux/fs/nfs/internal.h (revision bc000245)
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 	struct nfs_auth_info	auth_info;
92 	rpc_authflavor_t	selected_flavor;
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_server_remove_lists(struct nfs_server *);
158 void nfs_init_timeout_values(struct rpc_timeout *, int, unsigned int, unsigned int);
159 int nfs_init_server_rpcclient(struct nfs_server *, const struct rpc_timeout *t,
160 		rpc_authflavor_t);
161 struct nfs_server *nfs_alloc_server(void);
162 void nfs_server_copy_userdata(struct nfs_server *, struct nfs_server *);
163 
164 extern void nfs_cleanup_cb_ident_idr(struct net *);
165 extern void nfs_put_client(struct nfs_client *);
166 extern void nfs_free_client(struct nfs_client *);
167 extern struct nfs_client *nfs4_find_client_ident(struct net *, int);
168 extern struct nfs_client *
169 nfs4_find_client_sessionid(struct net *, const struct sockaddr *,
170 				struct nfs4_sessionid *, u32);
171 extern struct nfs_server *nfs_create_server(struct nfs_mount_info *,
172 					struct nfs_subversion *);
173 extern struct nfs_server *nfs4_create_server(
174 					struct nfs_mount_info *,
175 					struct nfs_subversion *);
176 extern struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *,
177 						      struct nfs_fh *);
178 extern int nfs4_update_server(struct nfs_server *server, const char *hostname,
179 					struct sockaddr *sap, size_t salen);
180 extern void nfs_free_server(struct nfs_server *server);
181 extern struct nfs_server *nfs_clone_server(struct nfs_server *,
182 					   struct nfs_fh *,
183 					   struct nfs_fattr *,
184 					   rpc_authflavor_t);
185 extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
186 extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
187 extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
188 					     const struct sockaddr *ds_addr,
189 					     int ds_addrlen, int ds_proto,
190 					     unsigned int ds_timeo,
191 					     unsigned int ds_retrans);
192 extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
193 						struct inode *);
194 #ifdef CONFIG_PROC_FS
195 extern int __init nfs_fs_proc_init(void);
196 extern void nfs_fs_proc_exit(void);
197 #else
198 static inline int nfs_fs_proc_init(void)
199 {
200 	return 0;
201 }
202 static inline void nfs_fs_proc_exit(void)
203 {
204 }
205 #endif
206 
207 #ifdef CONFIG_NFS_V4_1
208 int nfs_sockaddr_match_ipaddr(const struct sockaddr *, const struct sockaddr *);
209 #endif
210 
211 /* nfs3client.c */
212 #if IS_ENABLED(CONFIG_NFS_V3)
213 struct nfs_server *nfs3_create_server(struct nfs_mount_info *, struct nfs_subversion *);
214 struct nfs_server *nfs3_clone_server(struct nfs_server *, struct nfs_fh *,
215 				     struct nfs_fattr *, rpc_authflavor_t);
216 #endif
217 
218 /* callback_xdr.c */
219 extern struct svc_version nfs4_callback_version1;
220 extern struct svc_version nfs4_callback_version4;
221 
222 struct nfs_pageio_descriptor;
223 /* pagelist.c */
224 extern int __init nfs_init_nfspagecache(void);
225 extern void nfs_destroy_nfspagecache(void);
226 extern int __init nfs_init_readpagecache(void);
227 extern void nfs_destroy_readpagecache(void);
228 extern int __init nfs_init_writepagecache(void);
229 extern void nfs_destroy_writepagecache(void);
230 
231 extern int __init nfs_init_directcache(void);
232 extern void nfs_destroy_directcache(void);
233 extern bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount);
234 extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
235 			      struct nfs_pgio_header *hdr,
236 			      void (*release)(struct nfs_pgio_header *hdr));
237 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
238 int nfs_iocounter_wait(struct nfs_io_counter *c);
239 
240 static inline void nfs_iocounter_init(struct nfs_io_counter *c)
241 {
242 	c->flags = 0;
243 	atomic_set(&c->io_count, 0);
244 }
245 
246 /* nfs2xdr.c */
247 extern struct rpc_procinfo nfs_procedures[];
248 extern int nfs2_decode_dirent(struct xdr_stream *,
249 				struct nfs_entry *, int);
250 
251 /* nfs3xdr.c */
252 extern struct rpc_procinfo nfs3_procedures[];
253 extern int nfs3_decode_dirent(struct xdr_stream *,
254 				struct nfs_entry *, int);
255 
256 /* nfs4xdr.c */
257 #if IS_ENABLED(CONFIG_NFS_V4)
258 extern int nfs4_decode_dirent(struct xdr_stream *,
259 				struct nfs_entry *, int);
260 #endif
261 #ifdef CONFIG_NFS_V4_1
262 extern const u32 nfs41_maxread_overhead;
263 extern const u32 nfs41_maxwrite_overhead;
264 extern const u32 nfs41_maxgetdevinfo_overhead;
265 #endif
266 
267 /* nfs4proc.c */
268 #if IS_ENABLED(CONFIG_NFS_V4)
269 extern struct rpc_procinfo nfs4_procedures[];
270 #endif
271 
272 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
273 extern struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags);
274 static inline void nfs4_label_free(struct nfs4_label *label)
275 {
276 	if (label) {
277 		kfree(label->label);
278 		kfree(label);
279 	}
280 	return;
281 }
282 #else
283 static inline struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags) { return NULL; }
284 static inline void nfs4_label_free(void *label) {}
285 #endif /* CONFIG_NFS_V4_SECURITY_LABEL */
286 
287 /* proc.c */
288 void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
289 extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
290 			   const struct rpc_timeout *timeparms,
291 			   const char *ip_addr);
292 
293 /* dir.c */
294 extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
295 					    struct shrink_control *sc);
296 extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
297 					   struct shrink_control *sc);
298 struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
299 int nfs_create(struct inode *, struct dentry *, umode_t, bool);
300 int nfs_mkdir(struct inode *, struct dentry *, umode_t);
301 int nfs_rmdir(struct inode *, struct dentry *);
302 int nfs_unlink(struct inode *, struct dentry *);
303 int nfs_symlink(struct inode *, struct dentry *, const char *);
304 int nfs_link(struct dentry *, struct inode *, struct dentry *);
305 int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
306 int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
307 
308 /* file.c */
309 int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
310 loff_t nfs_file_llseek(struct file *, loff_t, int);
311 int nfs_file_flush(struct file *, fl_owner_t);
312 ssize_t nfs_file_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
313 ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
314 			     size_t, unsigned int);
315 int nfs_file_mmap(struct file *, struct vm_area_struct *);
316 ssize_t nfs_file_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
317 int nfs_file_release(struct inode *, struct file *);
318 int nfs_lock(struct file *, int, struct file_lock *);
319 int nfs_flock(struct file *, int, struct file_lock *);
320 ssize_t nfs_file_splice_write(struct pipe_inode_info *, struct file *, loff_t *,
321 			      size_t, unsigned int);
322 int nfs_check_flags(int);
323 int nfs_setlease(struct file *, long, struct file_lock **);
324 
325 /* inode.c */
326 extern struct workqueue_struct *nfsiod_workqueue;
327 extern struct inode *nfs_alloc_inode(struct super_block *sb);
328 extern void nfs_destroy_inode(struct inode *);
329 extern int nfs_write_inode(struct inode *, struct writeback_control *);
330 extern int nfs_drop_inode(struct inode *);
331 extern void nfs_clear_inode(struct inode *);
332 extern void nfs_evict_inode(struct inode *);
333 void nfs_zap_acl_cache(struct inode *inode);
334 extern int nfs_wait_bit_killable(void *word);
335 
336 /* super.c */
337 extern const struct super_operations nfs_sops;
338 extern struct file_system_type nfs_fs_type;
339 extern struct file_system_type nfs_xdev_fs_type;
340 #if IS_ENABLED(CONFIG_NFS_V4)
341 extern struct file_system_type nfs4_xdev_fs_type;
342 extern struct file_system_type nfs4_referral_fs_type;
343 #endif
344 bool nfs_auth_info_match(const struct nfs_auth_info *, rpc_authflavor_t);
345 struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
346 			struct nfs_subversion *);
347 void nfs_initialise_sb(struct super_block *);
348 int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
349 int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
350 struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
351 				   struct nfs_mount_info *, struct nfs_subversion *);
352 struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
353 struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
354 		const char *, struct nfs_mount_info *);
355 void nfs_kill_super(struct super_block *);
356 void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
357 
358 extern struct rpc_stat nfs_rpcstat;
359 
360 extern int __init register_nfs_fs(void);
361 extern void __exit unregister_nfs_fs(void);
362 extern void nfs_sb_active(struct super_block *sb);
363 extern void nfs_sb_deactive(struct super_block *sb);
364 
365 /* namespace.c */
366 #define NFS_PATH_CANONICAL 1
367 extern char *nfs_path(char **p, struct dentry *dentry,
368 		      char *buffer, ssize_t buflen, unsigned flags);
369 extern struct vfsmount *nfs_d_automount(struct path *path);
370 struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
371 			      struct nfs_fh *, struct nfs_fattr *);
372 struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
373 				 struct nfs_fattr *, rpc_authflavor_t);
374 
375 /* getroot.c */
376 extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
377 				   const char *);
378 #if IS_ENABLED(CONFIG_NFS_V4)
379 extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
380 				    const char *);
381 
382 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool);
383 #endif
384 
385 struct nfs_pgio_completion_ops;
386 /* read.c */
387 extern struct nfs_read_header *nfs_readhdr_alloc(void);
388 extern void nfs_readhdr_free(struct nfs_pgio_header *hdr);
389 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
390 			struct inode *inode,
391 			const struct nfs_pgio_completion_ops *compl_ops);
392 extern int nfs_initiate_read(struct rpc_clnt *clnt,
393 			     struct nfs_read_data *data,
394 			     const struct rpc_call_ops *call_ops, int flags);
395 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
396 extern int nfs_generic_pagein(struct nfs_pageio_descriptor *desc,
397 			      struct nfs_pgio_header *hdr);
398 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
399 extern void nfs_readdata_release(struct nfs_read_data *rdata);
400 
401 /* super.c */
402 void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
403 void nfs_umount_begin(struct super_block *);
404 int  nfs_statfs(struct dentry *, struct kstatfs *);
405 int  nfs_show_options(struct seq_file *, struct dentry *);
406 int  nfs_show_devname(struct seq_file *, struct dentry *);
407 int  nfs_show_path(struct seq_file *, struct dentry *);
408 int  nfs_show_stats(struct seq_file *, struct dentry *);
409 void nfs_put_super(struct super_block *);
410 int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
411 
412 /* write.c */
413 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
414 			struct inode *inode, int ioflags,
415 			const struct nfs_pgio_completion_ops *compl_ops);
416 extern struct nfs_write_header *nfs_writehdr_alloc(void);
417 extern void nfs_writehdr_free(struct nfs_pgio_header *hdr);
418 extern int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
419 			     struct nfs_pgio_header *hdr);
420 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
421 extern void nfs_writedata_release(struct nfs_write_data *wdata);
422 extern void nfs_commit_free(struct nfs_commit_data *p);
423 extern int nfs_initiate_write(struct rpc_clnt *clnt,
424 			      struct nfs_write_data *data,
425 			      const struct rpc_call_ops *call_ops,
426 			      int how, int flags);
427 extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
428 extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
429 extern int nfs_initiate_commit(struct rpc_clnt *clnt,
430 			       struct nfs_commit_data *data,
431 			       const struct rpc_call_ops *call_ops,
432 			       int how, int flags);
433 extern void nfs_init_commit(struct nfs_commit_data *data,
434 			    struct list_head *head,
435 			    struct pnfs_layout_segment *lseg,
436 			    struct nfs_commit_info *cinfo);
437 int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
438 			 struct nfs_commit_info *cinfo, int max);
439 int nfs_scan_commit(struct inode *inode, struct list_head *dst,
440 		    struct nfs_commit_info *cinfo);
441 void nfs_mark_request_commit(struct nfs_page *req,
442 			     struct pnfs_layout_segment *lseg,
443 			     struct nfs_commit_info *cinfo);
444 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
445 			    int how, struct nfs_commit_info *cinfo);
446 void nfs_retry_commit(struct list_head *page_list,
447 		      struct pnfs_layout_segment *lseg,
448 		      struct nfs_commit_info *cinfo);
449 void nfs_commitdata_release(struct nfs_commit_data *data);
450 void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
451 				 struct nfs_commit_info *cinfo);
452 void nfs_request_remove_commit_list(struct nfs_page *req,
453 				    struct nfs_commit_info *cinfo);
454 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
455 		    struct inode *inode,
456 		    struct nfs_direct_req *dreq);
457 int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
458 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
459 
460 #ifdef CONFIG_MIGRATION
461 extern int nfs_migrate_page(struct address_space *,
462 		struct page *, struct page *, enum migrate_mode);
463 #else
464 #define nfs_migrate_page NULL
465 #endif
466 
467 /* direct.c */
468 void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
469 			      struct nfs_direct_req *dreq);
470 static inline void nfs_inode_dio_wait(struct inode *inode)
471 {
472 	inode_dio_wait(inode);
473 }
474 extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
475 
476 /* nfs4proc.c */
477 extern void __nfs4_read_done_cb(struct nfs_read_data *);
478 extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
479 			    const struct rpc_timeout *timeparms,
480 			    const char *ip_addr);
481 extern int nfs40_walk_client_list(struct nfs_client *clp,
482 				struct nfs_client **result,
483 				struct rpc_cred *cred);
484 extern int nfs41_walk_client_list(struct nfs_client *clp,
485 				struct nfs_client **result,
486 				struct rpc_cred *cred);
487 
488 /*
489  * Determine the device name as a string
490  */
491 static inline char *nfs_devname(struct dentry *dentry,
492 				char *buffer, ssize_t buflen)
493 {
494 	char *dummy;
495 	return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
496 }
497 
498 /*
499  * Determine the actual block size (and log2 thereof)
500  */
501 static inline
502 unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
503 {
504 	/* make sure blocksize is a power of two */
505 	if ((bsize & (bsize - 1)) || nrbitsp) {
506 		unsigned char	nrbits;
507 
508 		for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
509 			;
510 		bsize = 1 << nrbits;
511 		if (nrbitsp)
512 			*nrbitsp = nrbits;
513 	}
514 
515 	return bsize;
516 }
517 
518 /*
519  * Calculate the number of 512byte blocks used.
520  */
521 static inline blkcnt_t nfs_calc_block_size(u64 tsize)
522 {
523 	blkcnt_t used = (tsize + 511) >> 9;
524 	return (used > ULONG_MAX) ? ULONG_MAX : used;
525 }
526 
527 /*
528  * Compute and set NFS server blocksize
529  */
530 static inline
531 unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
532 {
533 	if (bsize < NFS_MIN_FILE_IO_SIZE)
534 		bsize = NFS_DEF_FILE_IO_SIZE;
535 	else if (bsize >= NFS_MAX_FILE_IO_SIZE)
536 		bsize = NFS_MAX_FILE_IO_SIZE;
537 
538 	return nfs_block_bits(bsize, nrbitsp);
539 }
540 
541 /*
542  * Determine the maximum file size for a superblock
543  */
544 static inline
545 void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
546 {
547 	sb->s_maxbytes = (loff_t)maxfilesize;
548 	if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
549 		sb->s_maxbytes = MAX_LFS_FILESIZE;
550 }
551 
552 /*
553  * Determine the number of bytes of data the page contains
554  */
555 static inline
556 unsigned int nfs_page_length(struct page *page)
557 {
558 	loff_t i_size = i_size_read(page_file_mapping(page)->host);
559 
560 	if (i_size > 0) {
561 		pgoff_t page_index = page_file_index(page);
562 		pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
563 		if (page_index < end_index)
564 			return PAGE_CACHE_SIZE;
565 		if (page_index == end_index)
566 			return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
567 	}
568 	return 0;
569 }
570 
571 /*
572  * Convert a umode to a dirent->d_type
573  */
574 static inline
575 unsigned char nfs_umode_to_dtype(umode_t mode)
576 {
577 	return (mode >> 12) & 15;
578 }
579 
580 /*
581  * Determine the number of pages in an array of length 'len' and
582  * with a base offset of 'base'
583  */
584 static inline
585 unsigned int nfs_page_array_len(unsigned int base, size_t len)
586 {
587 	return ((unsigned long)len + (unsigned long)base +
588 		PAGE_SIZE - 1) >> PAGE_SHIFT;
589 }
590 
591 /*
592  * Convert a struct timespec into a 64-bit change attribute
593  *
594  * This does approximately the same thing as timespec_to_ns(),
595  * but for calculation efficiency, we multiply the seconds by
596  * 1024*1024*1024.
597  */
598 static inline
599 u64 nfs_timespec_to_change_attr(const struct timespec *ts)
600 {
601 	return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
602 }
603 
604 #ifdef CONFIG_CRC32
605 /**
606  * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
607  * @fh - pointer to filehandle
608  *
609  * returns a crc32 hash for the filehandle that is compatible with
610  * the one displayed by "wireshark".
611  */
612 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
613 {
614 	return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
615 }
616 #else
617 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
618 {
619 	return 0;
620 }
621 #endif
622