xref: /openbmc/linux/fs/nfs/internal.h (revision c819e2cf)
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 	return 1;
35 }
36 
37 struct nfs_clone_mount {
38 	const struct super_block *sb;
39 	const struct dentry *dentry;
40 	struct nfs_fh *fh;
41 	struct nfs_fattr *fattr;
42 	char *hostname;
43 	char *mnt_path;
44 	struct sockaddr *addr;
45 	size_t addrlen;
46 	rpc_authflavor_t authflavor;
47 };
48 
49 /*
50  * Note: RFC 1813 doesn't limit the number of auth flavors that
51  * a server can return, so make something up.
52  */
53 #define NFS_MAX_SECFLAVORS	(12)
54 
55 /*
56  * Value used if the user did not specify a port value.
57  */
58 #define NFS_UNSPEC_PORT		(-1)
59 
60 /*
61  * Maximum number of pages that readdir can use for creating
62  * a vmapped array of pages.
63  */
64 #define NFS_MAX_READDIR_PAGES 8
65 
66 struct nfs_client_initdata {
67 	unsigned long init_flags;
68 	const char *hostname;
69 	const struct sockaddr *addr;
70 	size_t addrlen;
71 	struct nfs_subversion *nfs_mod;
72 	int proto;
73 	u32 minorversion;
74 	struct net *net;
75 };
76 
77 /*
78  * In-kernel mount arguments
79  */
80 struct nfs_parsed_mount_data {
81 	int			flags;
82 	unsigned int		rsize, wsize;
83 	unsigned int		timeo, retrans;
84 	unsigned int		acregmin, acregmax,
85 				acdirmin, acdirmax;
86 	unsigned int		namlen;
87 	unsigned int		options;
88 	unsigned int		bsize;
89 	struct nfs_auth_info	auth_info;
90 	rpc_authflavor_t	selected_flavor;
91 	char			*client_address;
92 	unsigned int		version;
93 	unsigned int		minorversion;
94 	char			*fscache_uniq;
95 	bool			need_mount;
96 
97 	struct {
98 		struct sockaddr_storage	address;
99 		size_t			addrlen;
100 		char			*hostname;
101 		u32			version;
102 		int			port;
103 		unsigned short		protocol;
104 	} mount_server;
105 
106 	struct {
107 		struct sockaddr_storage	address;
108 		size_t			addrlen;
109 		char			*hostname;
110 		char			*export_path;
111 		int			port;
112 		unsigned short		protocol;
113 	} nfs_server;
114 
115 	struct security_mnt_opts lsm_opts;
116 	struct net		*net;
117 };
118 
119 /* mount_clnt.c */
120 struct nfs_mount_request {
121 	struct sockaddr		*sap;
122 	size_t			salen;
123 	char			*hostname;
124 	char			*dirpath;
125 	u32			version;
126 	unsigned short		protocol;
127 	struct nfs_fh		*fh;
128 	int			noresvport;
129 	unsigned int		*auth_flav_len;
130 	rpc_authflavor_t	*auth_flavs;
131 	struct net		*net;
132 };
133 
134 struct nfs_mount_info {
135 	void (*fill_super)(struct super_block *, struct nfs_mount_info *);
136 	int (*set_security)(struct super_block *, struct dentry *, struct nfs_mount_info *);
137 	struct nfs_parsed_mount_data *parsed;
138 	struct nfs_clone_mount *cloned;
139 	struct nfs_fh *mntfh;
140 };
141 
142 extern int nfs_mount(struct nfs_mount_request *info);
143 extern void nfs_umount(const struct nfs_mount_request *info);
144 
145 /* client.c */
146 extern const struct rpc_program nfs_program;
147 extern void nfs_clients_init(struct net *net);
148 extern struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *);
149 int nfs_create_rpc_client(struct nfs_client *, const struct rpc_timeout *, rpc_authflavor_t);
150 struct nfs_client *nfs_get_client(const struct nfs_client_initdata *,
151 				  const struct rpc_timeout *, const char *,
152 				  rpc_authflavor_t);
153 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *, struct nfs_fattr *);
154 void nfs_server_insert_lists(struct nfs_server *);
155 void nfs_server_remove_lists(struct nfs_server *);
156 void nfs_init_timeout_values(struct rpc_timeout *, int, unsigned int, unsigned int);
157 int nfs_init_server_rpcclient(struct nfs_server *, const struct rpc_timeout *t,
158 		rpc_authflavor_t);
159 struct nfs_server *nfs_alloc_server(void);
160 void nfs_server_copy_userdata(struct nfs_server *, struct nfs_server *);
161 
162 extern void nfs_cleanup_cb_ident_idr(struct net *);
163 extern void nfs_put_client(struct nfs_client *);
164 extern void nfs_free_client(struct nfs_client *);
165 extern struct nfs_client *nfs4_find_client_ident(struct net *, int);
166 extern struct nfs_client *
167 nfs4_find_client_sessionid(struct net *, const struct sockaddr *,
168 				struct nfs4_sessionid *, u32);
169 extern struct nfs_server *nfs_create_server(struct nfs_mount_info *,
170 					struct nfs_subversion *);
171 extern struct nfs_server *nfs4_create_server(
172 					struct nfs_mount_info *,
173 					struct nfs_subversion *);
174 extern struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *,
175 						      struct nfs_fh *);
176 extern int nfs4_update_server(struct nfs_server *server, const char *hostname,
177 					struct sockaddr *sap, size_t salen,
178 					struct net *net);
179 extern void nfs_free_server(struct nfs_server *server);
180 extern struct nfs_server *nfs_clone_server(struct nfs_server *,
181 					   struct nfs_fh *,
182 					   struct nfs_fattr *,
183 					   rpc_authflavor_t);
184 extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
185 extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
186 extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
187 					     const struct sockaddr *ds_addr,
188 					     int ds_addrlen, int ds_proto,
189 					     unsigned int ds_timeo,
190 					     unsigned int ds_retrans);
191 extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
192 						struct inode *);
193 #ifdef CONFIG_PROC_FS
194 extern int __init nfs_fs_proc_init(void);
195 extern void nfs_fs_proc_exit(void);
196 extern int nfs_fs_proc_net_init(struct net *net);
197 extern void nfs_fs_proc_net_exit(struct net *net);
198 #else
199 static inline int nfs_fs_proc_net_init(struct net *net)
200 {
201 	return 0;
202 }
203 static inline void nfs_fs_proc_net_exit(struct net *net)
204 {
205 }
206 static inline int nfs_fs_proc_init(void)
207 {
208 	return 0;
209 }
210 static inline void nfs_fs_proc_exit(void)
211 {
212 }
213 #endif
214 
215 #ifdef CONFIG_NFS_V4_1
216 int nfs_sockaddr_match_ipaddr(const struct sockaddr *, const struct sockaddr *);
217 #endif
218 
219 /* callback_xdr.c */
220 extern struct svc_version nfs4_callback_version1;
221 extern struct svc_version nfs4_callback_version4;
222 
223 struct nfs_pageio_descriptor;
224 /* pagelist.c */
225 extern int __init nfs_init_nfspagecache(void);
226 extern void nfs_destroy_nfspagecache(void);
227 extern int __init nfs_init_readpagecache(void);
228 extern void nfs_destroy_readpagecache(void);
229 extern int __init nfs_init_writepagecache(void);
230 extern void nfs_destroy_writepagecache(void);
231 
232 extern int __init nfs_init_directcache(void);
233 extern void nfs_destroy_directcache(void);
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 extern const struct nfs_pageio_ops nfs_pgio_rw_ops;
241 struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *);
242 void nfs_pgio_header_free(struct nfs_pgio_header *);
243 void nfs_pgio_data_destroy(struct nfs_pgio_header *);
244 int nfs_generic_pgio(struct nfs_pageio_descriptor *, struct nfs_pgio_header *);
245 int nfs_initiate_pgio(struct rpc_clnt *, struct nfs_pgio_header *,
246 		      const struct rpc_call_ops *, int, int);
247 void nfs_free_request(struct nfs_page *req);
248 
249 static inline void nfs_iocounter_init(struct nfs_io_counter *c)
250 {
251 	c->flags = 0;
252 	atomic_set(&c->io_count, 0);
253 }
254 
255 /* nfs2xdr.c */
256 extern struct rpc_procinfo nfs_procedures[];
257 extern int nfs2_decode_dirent(struct xdr_stream *,
258 				struct nfs_entry *, int);
259 
260 /* nfs3xdr.c */
261 extern struct rpc_procinfo nfs3_procedures[];
262 extern int nfs3_decode_dirent(struct xdr_stream *,
263 				struct nfs_entry *, int);
264 
265 /* nfs4xdr.c */
266 #if IS_ENABLED(CONFIG_NFS_V4)
267 extern int nfs4_decode_dirent(struct xdr_stream *,
268 				struct nfs_entry *, int);
269 #endif
270 #ifdef CONFIG_NFS_V4_1
271 extern const u32 nfs41_maxread_overhead;
272 extern const u32 nfs41_maxwrite_overhead;
273 extern const u32 nfs41_maxgetdevinfo_overhead;
274 #endif
275 
276 /* nfs4proc.c */
277 #if IS_ENABLED(CONFIG_NFS_V4)
278 extern struct rpc_procinfo nfs4_procedures[];
279 #endif
280 
281 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
282 extern struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags);
283 static inline void nfs4_label_free(struct nfs4_label *label)
284 {
285 	if (label) {
286 		kfree(label->label);
287 		kfree(label);
288 	}
289 	return;
290 }
291 
292 static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
293 {
294 	if (nfs_server_capable(&nfsi->vfs_inode, NFS_CAP_SECURITY_LABEL))
295 		nfsi->cache_validity |= NFS_INO_INVALID_LABEL;
296 }
297 #else
298 static inline struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags) { return NULL; }
299 static inline void nfs4_label_free(void *label) {}
300 static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
301 {
302 }
303 #endif /* CONFIG_NFS_V4_SECURITY_LABEL */
304 
305 /* proc.c */
306 void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
307 extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
308 			   const struct rpc_timeout *timeparms,
309 			   const char *ip_addr);
310 
311 /* dir.c */
312 extern void nfs_force_use_readdirplus(struct inode *dir);
313 extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
314 					    struct shrink_control *sc);
315 extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
316 					   struct shrink_control *sc);
317 struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
318 int nfs_create(struct inode *, struct dentry *, umode_t, bool);
319 int nfs_mkdir(struct inode *, struct dentry *, umode_t);
320 int nfs_rmdir(struct inode *, struct dentry *);
321 int nfs_unlink(struct inode *, struct dentry *);
322 int nfs_symlink(struct inode *, struct dentry *, const char *);
323 int nfs_link(struct dentry *, struct inode *, struct dentry *);
324 int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
325 int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
326 
327 /* file.c */
328 int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
329 loff_t nfs_file_llseek(struct file *, loff_t, int);
330 int nfs_file_flush(struct file *, fl_owner_t);
331 ssize_t nfs_file_read(struct kiocb *, struct iov_iter *);
332 ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
333 			     size_t, unsigned int);
334 int nfs_file_mmap(struct file *, struct vm_area_struct *);
335 ssize_t nfs_file_write(struct kiocb *, struct iov_iter *);
336 int nfs_file_release(struct inode *, struct file *);
337 int nfs_lock(struct file *, int, struct file_lock *);
338 int nfs_flock(struct file *, int, struct file_lock *);
339 int nfs_check_flags(int);
340 
341 /* inode.c */
342 extern struct workqueue_struct *nfsiod_workqueue;
343 extern struct inode *nfs_alloc_inode(struct super_block *sb);
344 extern void nfs_destroy_inode(struct inode *);
345 extern int nfs_write_inode(struct inode *, struct writeback_control *);
346 extern int nfs_drop_inode(struct inode *);
347 extern void nfs_clear_inode(struct inode *);
348 extern void nfs_evict_inode(struct inode *);
349 void nfs_zap_acl_cache(struct inode *inode);
350 extern int nfs_wait_bit_killable(struct wait_bit_key *key);
351 
352 /* super.c */
353 extern const struct super_operations nfs_sops;
354 extern struct file_system_type nfs_fs_type;
355 extern struct file_system_type nfs_xdev_fs_type;
356 #if IS_ENABLED(CONFIG_NFS_V4)
357 extern struct file_system_type nfs4_xdev_fs_type;
358 extern struct file_system_type nfs4_referral_fs_type;
359 #endif
360 bool nfs_auth_info_match(const struct nfs_auth_info *, rpc_authflavor_t);
361 struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
362 			struct nfs_subversion *);
363 void nfs_initialise_sb(struct super_block *);
364 int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
365 int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
366 struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
367 				   struct nfs_mount_info *, struct nfs_subversion *);
368 struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
369 struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
370 		const char *, struct nfs_mount_info *);
371 void nfs_kill_super(struct super_block *);
372 void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
373 
374 extern struct rpc_stat nfs_rpcstat;
375 
376 extern int __init register_nfs_fs(void);
377 extern void __exit unregister_nfs_fs(void);
378 extern void nfs_sb_active(struct super_block *sb);
379 extern void nfs_sb_deactive(struct super_block *sb);
380 
381 /* namespace.c */
382 #define NFS_PATH_CANONICAL 1
383 extern char *nfs_path(char **p, struct dentry *dentry,
384 		      char *buffer, ssize_t buflen, unsigned flags);
385 extern struct vfsmount *nfs_d_automount(struct path *path);
386 struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
387 			      struct nfs_fh *, struct nfs_fattr *);
388 struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
389 				 struct nfs_fattr *, rpc_authflavor_t);
390 
391 /* getroot.c */
392 extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
393 				   const char *);
394 #if IS_ENABLED(CONFIG_NFS_V4)
395 extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
396 				    const char *);
397 
398 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool);
399 #endif
400 
401 struct nfs_pgio_completion_ops;
402 /* read.c */
403 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
404 			struct inode *inode, bool force_mds,
405 			const struct nfs_pgio_completion_ops *compl_ops);
406 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
407 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
408 
409 /* super.c */
410 void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
411 void nfs_umount_begin(struct super_block *);
412 int  nfs_statfs(struct dentry *, struct kstatfs *);
413 int  nfs_show_options(struct seq_file *, struct dentry *);
414 int  nfs_show_devname(struct seq_file *, struct dentry *);
415 int  nfs_show_path(struct seq_file *, struct dentry *);
416 int  nfs_show_stats(struct seq_file *, struct dentry *);
417 void nfs_put_super(struct super_block *);
418 int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
419 
420 /* write.c */
421 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
422 			struct inode *inode, int ioflags, bool force_mds,
423 			const struct nfs_pgio_completion_ops *compl_ops);
424 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
425 extern void nfs_commit_free(struct nfs_commit_data *p);
426 extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
427 extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
428 extern int nfs_initiate_commit(struct rpc_clnt *clnt,
429 			       struct nfs_commit_data *data,
430 			       const struct rpc_call_ops *call_ops,
431 			       int how, int flags);
432 extern void nfs_init_commit(struct nfs_commit_data *data,
433 			    struct list_head *head,
434 			    struct pnfs_layout_segment *lseg,
435 			    struct nfs_commit_info *cinfo);
436 int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
437 			 struct nfs_commit_info *cinfo, int max);
438 unsigned long nfs_reqs_to_commit(struct nfs_commit_info *);
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_write_need_commit(struct nfs_pgio_header *);
445 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
446 			    int how, struct nfs_commit_info *cinfo);
447 void nfs_retry_commit(struct list_head *page_list,
448 		      struct pnfs_layout_segment *lseg,
449 		      struct nfs_commit_info *cinfo);
450 void nfs_commitdata_release(struct nfs_commit_data *data);
451 void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
452 				 struct nfs_commit_info *cinfo);
453 void nfs_request_remove_commit_list(struct nfs_page *req,
454 				    struct nfs_commit_info *cinfo);
455 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
456 		    struct inode *inode,
457 		    struct nfs_direct_req *dreq);
458 int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
459 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
460 
461 #ifdef CONFIG_MIGRATION
462 extern int nfs_migrate_page(struct address_space *,
463 		struct page *, struct page *, enum migrate_mode);
464 #else
465 #define nfs_migrate_page NULL
466 #endif
467 
468 /* unlink.c */
469 extern struct rpc_task *
470 nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
471 		 struct dentry *old_dentry, struct dentry *new_dentry,
472 		 void (*complete)(struct rpc_task *, struct nfs_renamedata *));
473 extern int nfs_sillyrename(struct inode *dir, struct dentry *dentry);
474 
475 /* direct.c */
476 void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
477 			      struct nfs_direct_req *dreq);
478 static inline void nfs_inode_dio_wait(struct inode *inode)
479 {
480 	inode_dio_wait(inode);
481 }
482 extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
483 
484 /* nfs4proc.c */
485 extern void __nfs4_read_done_cb(struct nfs_pgio_header *);
486 extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
487 			    const struct rpc_timeout *timeparms,
488 			    const char *ip_addr);
489 extern int nfs40_walk_client_list(struct nfs_client *clp,
490 				struct nfs_client **result,
491 				struct rpc_cred *cred);
492 extern int nfs41_walk_client_list(struct nfs_client *clp,
493 				struct nfs_client **result,
494 				struct rpc_cred *cred);
495 
496 /*
497  * Determine the device name as a string
498  */
499 static inline char *nfs_devname(struct dentry *dentry,
500 				char *buffer, ssize_t buflen)
501 {
502 	char *dummy;
503 	return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
504 }
505 
506 /*
507  * Determine the actual block size (and log2 thereof)
508  */
509 static inline
510 unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
511 {
512 	/* make sure blocksize is a power of two */
513 	if ((bsize & (bsize - 1)) || nrbitsp) {
514 		unsigned char	nrbits;
515 
516 		for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
517 			;
518 		bsize = 1 << nrbits;
519 		if (nrbitsp)
520 			*nrbitsp = nrbits;
521 	}
522 
523 	return bsize;
524 }
525 
526 /*
527  * Calculate the number of 512byte blocks used.
528  */
529 static inline blkcnt_t nfs_calc_block_size(u64 tsize)
530 {
531 	blkcnt_t used = (tsize + 511) >> 9;
532 	return (used > ULONG_MAX) ? ULONG_MAX : used;
533 }
534 
535 /*
536  * Compute and set NFS server blocksize
537  */
538 static inline
539 unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
540 {
541 	if (bsize < NFS_MIN_FILE_IO_SIZE)
542 		bsize = NFS_DEF_FILE_IO_SIZE;
543 	else if (bsize >= NFS_MAX_FILE_IO_SIZE)
544 		bsize = NFS_MAX_FILE_IO_SIZE;
545 
546 	return nfs_block_bits(bsize, nrbitsp);
547 }
548 
549 /*
550  * Determine the maximum file size for a superblock
551  */
552 static inline
553 void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
554 {
555 	sb->s_maxbytes = (loff_t)maxfilesize;
556 	if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
557 		sb->s_maxbytes = MAX_LFS_FILESIZE;
558 }
559 
560 /*
561  * Determine the number of bytes of data the page contains
562  */
563 static inline
564 unsigned int nfs_page_length(struct page *page)
565 {
566 	loff_t i_size = i_size_read(page_file_mapping(page)->host);
567 
568 	if (i_size > 0) {
569 		pgoff_t page_index = page_file_index(page);
570 		pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
571 		if (page_index < end_index)
572 			return PAGE_CACHE_SIZE;
573 		if (page_index == end_index)
574 			return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
575 	}
576 	return 0;
577 }
578 
579 /*
580  * Convert a umode to a dirent->d_type
581  */
582 static inline
583 unsigned char nfs_umode_to_dtype(umode_t mode)
584 {
585 	return (mode >> 12) & 15;
586 }
587 
588 /*
589  * Determine the number of pages in an array of length 'len' and
590  * with a base offset of 'base'
591  */
592 static inline
593 unsigned int nfs_page_array_len(unsigned int base, size_t len)
594 {
595 	return ((unsigned long)len + (unsigned long)base +
596 		PAGE_SIZE - 1) >> PAGE_SHIFT;
597 }
598 
599 /*
600  * Convert a struct timespec into a 64-bit change attribute
601  *
602  * This does approximately the same thing as timespec_to_ns(),
603  * but for calculation efficiency, we multiply the seconds by
604  * 1024*1024*1024.
605  */
606 static inline
607 u64 nfs_timespec_to_change_attr(const struct timespec *ts)
608 {
609 	return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
610 }
611 
612 #ifdef CONFIG_CRC32
613 /**
614  * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
615  * @fh - pointer to filehandle
616  *
617  * returns a crc32 hash for the filehandle that is compatible with
618  * the one displayed by "wireshark".
619  */
620 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
621 {
622 	return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
623 }
624 #else
625 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
626 {
627 	return 0;
628 }
629 #endif
630