xref: /openbmc/linux/fs/nfs/internal.h (revision 609e478b)
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 					struct net *net);
181 extern void nfs_free_server(struct nfs_server *server);
182 extern struct nfs_server *nfs_clone_server(struct nfs_server *,
183 					   struct nfs_fh *,
184 					   struct nfs_fattr *,
185 					   rpc_authflavor_t);
186 extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
187 extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
188 extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
189 					     const struct sockaddr *ds_addr,
190 					     int ds_addrlen, int ds_proto,
191 					     unsigned int ds_timeo,
192 					     unsigned int ds_retrans);
193 extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
194 						struct inode *);
195 #ifdef CONFIG_PROC_FS
196 extern int __init nfs_fs_proc_init(void);
197 extern void nfs_fs_proc_exit(void);
198 extern int nfs_fs_proc_net_init(struct net *net);
199 extern void nfs_fs_proc_net_exit(struct net *net);
200 #else
201 static inline int nfs_fs_proc_net_init(struct net *net)
202 {
203 	return 0;
204 }
205 static inline void nfs_fs_proc_net_exit(struct net *net)
206 {
207 }
208 static inline int nfs_fs_proc_init(void)
209 {
210 	return 0;
211 }
212 static inline void nfs_fs_proc_exit(void)
213 {
214 }
215 #endif
216 
217 #ifdef CONFIG_NFS_V4_1
218 int nfs_sockaddr_match_ipaddr(const struct sockaddr *, const struct sockaddr *);
219 #endif
220 
221 /* callback_xdr.c */
222 extern struct svc_version nfs4_callback_version1;
223 extern struct svc_version nfs4_callback_version4;
224 
225 struct nfs_pageio_descriptor;
226 /* pagelist.c */
227 extern int __init nfs_init_nfspagecache(void);
228 extern void nfs_destroy_nfspagecache(void);
229 extern int __init nfs_init_readpagecache(void);
230 extern void nfs_destroy_readpagecache(void);
231 extern int __init nfs_init_writepagecache(void);
232 extern void nfs_destroy_writepagecache(void);
233 
234 extern int __init nfs_init_directcache(void);
235 extern void nfs_destroy_directcache(void);
236 extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
237 			      struct nfs_pgio_header *hdr,
238 			      void (*release)(struct nfs_pgio_header *hdr));
239 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
240 int nfs_iocounter_wait(struct nfs_io_counter *c);
241 
242 extern const struct nfs_pageio_ops nfs_pgio_rw_ops;
243 struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *);
244 void nfs_pgio_header_free(struct nfs_pgio_header *);
245 void nfs_pgio_data_destroy(struct nfs_pgio_header *);
246 int nfs_generic_pgio(struct nfs_pageio_descriptor *, struct nfs_pgio_header *);
247 int nfs_initiate_pgio(struct rpc_clnt *, struct nfs_pgio_header *,
248 		      const struct rpc_call_ops *, int, int);
249 void nfs_free_request(struct nfs_page *req);
250 
251 static inline void nfs_iocounter_init(struct nfs_io_counter *c)
252 {
253 	c->flags = 0;
254 	atomic_set(&c->io_count, 0);
255 }
256 
257 /* nfs2xdr.c */
258 extern struct rpc_procinfo nfs_procedures[];
259 extern int nfs2_decode_dirent(struct xdr_stream *,
260 				struct nfs_entry *, int);
261 
262 /* nfs3xdr.c */
263 extern struct rpc_procinfo nfs3_procedures[];
264 extern int nfs3_decode_dirent(struct xdr_stream *,
265 				struct nfs_entry *, int);
266 
267 /* nfs4xdr.c */
268 #if IS_ENABLED(CONFIG_NFS_V4)
269 extern int nfs4_decode_dirent(struct xdr_stream *,
270 				struct nfs_entry *, int);
271 #endif
272 #ifdef CONFIG_NFS_V4_1
273 extern const u32 nfs41_maxread_overhead;
274 extern const u32 nfs41_maxwrite_overhead;
275 extern const u32 nfs41_maxgetdevinfo_overhead;
276 #endif
277 
278 /* nfs4proc.c */
279 #if IS_ENABLED(CONFIG_NFS_V4)
280 extern struct rpc_procinfo nfs4_procedures[];
281 #endif
282 
283 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
284 extern struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags);
285 static inline void nfs4_label_free(struct nfs4_label *label)
286 {
287 	if (label) {
288 		kfree(label->label);
289 		kfree(label);
290 	}
291 	return;
292 }
293 
294 static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
295 {
296 	if (nfs_server_capable(&nfsi->vfs_inode, NFS_CAP_SECURITY_LABEL))
297 		nfsi->cache_validity |= NFS_INO_INVALID_LABEL;
298 }
299 #else
300 static inline struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags) { return NULL; }
301 static inline void nfs4_label_free(void *label) {}
302 static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
303 {
304 }
305 #endif /* CONFIG_NFS_V4_SECURITY_LABEL */
306 
307 /* proc.c */
308 void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
309 extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
310 			   const struct rpc_timeout *timeparms,
311 			   const char *ip_addr);
312 
313 /* dir.c */
314 extern void nfs_force_use_readdirplus(struct inode *dir);
315 extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
316 					    struct shrink_control *sc);
317 extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
318 					   struct shrink_control *sc);
319 struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
320 int nfs_create(struct inode *, struct dentry *, umode_t, bool);
321 int nfs_mkdir(struct inode *, struct dentry *, umode_t);
322 int nfs_rmdir(struct inode *, struct dentry *);
323 int nfs_unlink(struct inode *, struct dentry *);
324 int nfs_symlink(struct inode *, struct dentry *, const char *);
325 int nfs_link(struct dentry *, struct inode *, struct dentry *);
326 int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
327 int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
328 
329 /* file.c */
330 int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
331 loff_t nfs_file_llseek(struct file *, loff_t, int);
332 int nfs_file_flush(struct file *, fl_owner_t);
333 ssize_t nfs_file_read(struct kiocb *, struct iov_iter *);
334 ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
335 			     size_t, unsigned int);
336 int nfs_file_mmap(struct file *, struct vm_area_struct *);
337 ssize_t nfs_file_write(struct kiocb *, struct iov_iter *);
338 int nfs_file_release(struct inode *, struct file *);
339 int nfs_lock(struct file *, int, struct file_lock *);
340 int nfs_flock(struct file *, int, struct file_lock *);
341 int nfs_check_flags(int);
342 
343 /* inode.c */
344 extern struct workqueue_struct *nfsiod_workqueue;
345 extern struct inode *nfs_alloc_inode(struct super_block *sb);
346 extern void nfs_destroy_inode(struct inode *);
347 extern int nfs_write_inode(struct inode *, struct writeback_control *);
348 extern int nfs_drop_inode(struct inode *);
349 extern void nfs_clear_inode(struct inode *);
350 extern void nfs_evict_inode(struct inode *);
351 void nfs_zap_acl_cache(struct inode *inode);
352 extern int nfs_wait_bit_killable(struct wait_bit_key *key);
353 
354 /* super.c */
355 extern const struct super_operations nfs_sops;
356 extern struct file_system_type nfs_fs_type;
357 extern struct file_system_type nfs_xdev_fs_type;
358 #if IS_ENABLED(CONFIG_NFS_V4)
359 extern struct file_system_type nfs4_xdev_fs_type;
360 extern struct file_system_type nfs4_referral_fs_type;
361 #endif
362 bool nfs_auth_info_match(const struct nfs_auth_info *, rpc_authflavor_t);
363 struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
364 			struct nfs_subversion *);
365 void nfs_initialise_sb(struct super_block *);
366 int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
367 int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
368 struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
369 				   struct nfs_mount_info *, struct nfs_subversion *);
370 struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
371 struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
372 		const char *, struct nfs_mount_info *);
373 void nfs_kill_super(struct super_block *);
374 void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
375 
376 extern struct rpc_stat nfs_rpcstat;
377 
378 extern int __init register_nfs_fs(void);
379 extern void __exit unregister_nfs_fs(void);
380 extern void nfs_sb_active(struct super_block *sb);
381 extern void nfs_sb_deactive(struct super_block *sb);
382 
383 /* namespace.c */
384 #define NFS_PATH_CANONICAL 1
385 extern char *nfs_path(char **p, struct dentry *dentry,
386 		      char *buffer, ssize_t buflen, unsigned flags);
387 extern struct vfsmount *nfs_d_automount(struct path *path);
388 struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
389 			      struct nfs_fh *, struct nfs_fattr *);
390 struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
391 				 struct nfs_fattr *, rpc_authflavor_t);
392 
393 /* getroot.c */
394 extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
395 				   const char *);
396 #if IS_ENABLED(CONFIG_NFS_V4)
397 extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
398 				    const char *);
399 
400 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool);
401 #endif
402 
403 struct nfs_pgio_completion_ops;
404 /* read.c */
405 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
406 			struct inode *inode, bool force_mds,
407 			const struct nfs_pgio_completion_ops *compl_ops);
408 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
409 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
410 
411 /* super.c */
412 void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
413 void nfs_umount_begin(struct super_block *);
414 int  nfs_statfs(struct dentry *, struct kstatfs *);
415 int  nfs_show_options(struct seq_file *, struct dentry *);
416 int  nfs_show_devname(struct seq_file *, struct dentry *);
417 int  nfs_show_path(struct seq_file *, struct dentry *);
418 int  nfs_show_stats(struct seq_file *, struct dentry *);
419 void nfs_put_super(struct super_block *);
420 int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
421 
422 /* write.c */
423 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
424 			struct inode *inode, int ioflags, bool force_mds,
425 			const struct nfs_pgio_completion_ops *compl_ops);
426 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
427 extern void nfs_commit_free(struct nfs_commit_data *p);
428 extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
429 extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
430 extern int nfs_initiate_commit(struct rpc_clnt *clnt,
431 			       struct nfs_commit_data *data,
432 			       const struct rpc_call_ops *call_ops,
433 			       int how, int flags);
434 extern void nfs_init_commit(struct nfs_commit_data *data,
435 			    struct list_head *head,
436 			    struct pnfs_layout_segment *lseg,
437 			    struct nfs_commit_info *cinfo);
438 int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
439 			 struct nfs_commit_info *cinfo, int max);
440 unsigned long nfs_reqs_to_commit(struct nfs_commit_info *);
441 int nfs_scan_commit(struct inode *inode, struct list_head *dst,
442 		    struct nfs_commit_info *cinfo);
443 void nfs_mark_request_commit(struct nfs_page *req,
444 			     struct pnfs_layout_segment *lseg,
445 			     struct nfs_commit_info *cinfo);
446 int nfs_write_need_commit(struct nfs_pgio_header *);
447 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
448 			    int how, struct nfs_commit_info *cinfo);
449 void nfs_retry_commit(struct list_head *page_list,
450 		      struct pnfs_layout_segment *lseg,
451 		      struct nfs_commit_info *cinfo);
452 void nfs_commitdata_release(struct nfs_commit_data *data);
453 void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
454 				 struct nfs_commit_info *cinfo);
455 void nfs_request_remove_commit_list(struct nfs_page *req,
456 				    struct nfs_commit_info *cinfo);
457 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
458 		    struct inode *inode,
459 		    struct nfs_direct_req *dreq);
460 int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
461 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
462 
463 #ifdef CONFIG_MIGRATION
464 extern int nfs_migrate_page(struct address_space *,
465 		struct page *, struct page *, enum migrate_mode);
466 #else
467 #define nfs_migrate_page NULL
468 #endif
469 
470 /* unlink.c */
471 extern struct rpc_task *
472 nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
473 		 struct dentry *old_dentry, struct dentry *new_dentry,
474 		 void (*complete)(struct rpc_task *, struct nfs_renamedata *));
475 extern int nfs_sillyrename(struct inode *dir, struct dentry *dentry);
476 
477 /* direct.c */
478 void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
479 			      struct nfs_direct_req *dreq);
480 static inline void nfs_inode_dio_wait(struct inode *inode)
481 {
482 	inode_dio_wait(inode);
483 }
484 extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
485 
486 /* nfs4proc.c */
487 extern void __nfs4_read_done_cb(struct nfs_pgio_header *);
488 extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
489 			    const struct rpc_timeout *timeparms,
490 			    const char *ip_addr);
491 extern int nfs40_walk_client_list(struct nfs_client *clp,
492 				struct nfs_client **result,
493 				struct rpc_cred *cred);
494 extern int nfs41_walk_client_list(struct nfs_client *clp,
495 				struct nfs_client **result,
496 				struct rpc_cred *cred);
497 
498 /*
499  * Determine the device name as a string
500  */
501 static inline char *nfs_devname(struct dentry *dentry,
502 				char *buffer, ssize_t buflen)
503 {
504 	char *dummy;
505 	return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
506 }
507 
508 /*
509  * Determine the actual block size (and log2 thereof)
510  */
511 static inline
512 unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
513 {
514 	/* make sure blocksize is a power of two */
515 	if ((bsize & (bsize - 1)) || nrbitsp) {
516 		unsigned char	nrbits;
517 
518 		for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
519 			;
520 		bsize = 1 << nrbits;
521 		if (nrbitsp)
522 			*nrbitsp = nrbits;
523 	}
524 
525 	return bsize;
526 }
527 
528 /*
529  * Calculate the number of 512byte blocks used.
530  */
531 static inline blkcnt_t nfs_calc_block_size(u64 tsize)
532 {
533 	blkcnt_t used = (tsize + 511) >> 9;
534 	return (used > ULONG_MAX) ? ULONG_MAX : used;
535 }
536 
537 /*
538  * Compute and set NFS server blocksize
539  */
540 static inline
541 unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
542 {
543 	if (bsize < NFS_MIN_FILE_IO_SIZE)
544 		bsize = NFS_DEF_FILE_IO_SIZE;
545 	else if (bsize >= NFS_MAX_FILE_IO_SIZE)
546 		bsize = NFS_MAX_FILE_IO_SIZE;
547 
548 	return nfs_block_bits(bsize, nrbitsp);
549 }
550 
551 /*
552  * Determine the maximum file size for a superblock
553  */
554 static inline
555 void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
556 {
557 	sb->s_maxbytes = (loff_t)maxfilesize;
558 	if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
559 		sb->s_maxbytes = MAX_LFS_FILESIZE;
560 }
561 
562 /*
563  * Determine the number of bytes of data the page contains
564  */
565 static inline
566 unsigned int nfs_page_length(struct page *page)
567 {
568 	loff_t i_size = i_size_read(page_file_mapping(page)->host);
569 
570 	if (i_size > 0) {
571 		pgoff_t page_index = page_file_index(page);
572 		pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
573 		if (page_index < end_index)
574 			return PAGE_CACHE_SIZE;
575 		if (page_index == end_index)
576 			return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
577 	}
578 	return 0;
579 }
580 
581 /*
582  * Convert a umode to a dirent->d_type
583  */
584 static inline
585 unsigned char nfs_umode_to_dtype(umode_t mode)
586 {
587 	return (mode >> 12) & 15;
588 }
589 
590 /*
591  * Determine the number of pages in an array of length 'len' and
592  * with a base offset of 'base'
593  */
594 static inline
595 unsigned int nfs_page_array_len(unsigned int base, size_t len)
596 {
597 	return ((unsigned long)len + (unsigned long)base +
598 		PAGE_SIZE - 1) >> PAGE_SHIFT;
599 }
600 
601 /*
602  * Convert a struct timespec into a 64-bit change attribute
603  *
604  * This does approximately the same thing as timespec_to_ns(),
605  * but for calculation efficiency, we multiply the seconds by
606  * 1024*1024*1024.
607  */
608 static inline
609 u64 nfs_timespec_to_change_attr(const struct timespec *ts)
610 {
611 	return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
612 }
613 
614 #ifdef CONFIG_CRC32
615 /**
616  * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
617  * @fh - pointer to filehandle
618  *
619  * returns a crc32 hash for the filehandle that is compatible with
620  * the one displayed by "wireshark".
621  */
622 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
623 {
624 	return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
625 }
626 #else
627 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
628 {
629 	return 0;
630 }
631 #endif
632