xref: /openbmc/linux/fs/nfs/internal.h (revision 3d9b448b)
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 #include <linux/nfs_page.h>
10 
11 #define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
12 
13 struct nfs_string;
14 
15 /* Maximum number of readahead requests
16  * FIXME: this should really be a sysctl so that users may tune it to suit
17  *        their needs. People that do NFS over a slow network, might for
18  *        instance want to reduce it to something closer to 1 for improved
19  *        interactive response.
20  */
21 #define NFS_MAX_READAHEAD	(RPC_DEF_SLOT_TABLE - 1)
22 
23 static inline void nfs_attr_check_mountpoint(struct super_block *parent, struct nfs_fattr *fattr)
24 {
25 	if (!nfs_fsid_equal(&NFS_SB(parent)->fsid, &fattr->fsid))
26 		fattr->valid |= NFS_ATTR_FATTR_MOUNTPOINT;
27 }
28 
29 static inline int nfs_attr_use_mounted_on_fileid(struct nfs_fattr *fattr)
30 {
31 	if (((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) == 0) ||
32 	    (((fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT) == 0) &&
33 	     ((fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) == 0)))
34 		return 0;
35 	return 1;
36 }
37 
38 struct nfs_clone_mount {
39 	const struct super_block *sb;
40 	const struct dentry *dentry;
41 	struct nfs_fh *fh;
42 	struct nfs_fattr *fattr;
43 	char *hostname;
44 	char *mnt_path;
45 	struct sockaddr *addr;
46 	size_t addrlen;
47 	rpc_authflavor_t authflavor;
48 };
49 
50 /*
51  * Note: RFC 1813 doesn't limit the number of auth flavors that
52  * a server can return, so make something up.
53  */
54 #define NFS_MAX_SECFLAVORS	(12)
55 
56 /*
57  * Value used if the user did not specify a port value.
58  */
59 #define NFS_UNSPEC_PORT		(-1)
60 
61 /*
62  * Maximum number of pages that readdir can use for creating
63  * a vmapped array of pages.
64  */
65 #define NFS_MAX_READDIR_PAGES 8
66 
67 struct nfs_client_initdata {
68 	unsigned long init_flags;
69 	const char *hostname;
70 	const struct sockaddr *addr;
71 	size_t addrlen;
72 	struct nfs_subversion *nfs_mod;
73 	int proto;
74 	u32 minorversion;
75 	struct net *net;
76 };
77 
78 /*
79  * In-kernel mount arguments
80  */
81 struct nfs_parsed_mount_data {
82 	int			flags;
83 	unsigned int		rsize, wsize;
84 	unsigned int		timeo, retrans;
85 	unsigned int		acregmin, acregmax,
86 				acdirmin, acdirmax;
87 	unsigned int		namlen;
88 	unsigned int		options;
89 	unsigned int		bsize;
90 	struct nfs_auth_info	auth_info;
91 	rpc_authflavor_t	selected_flavor;
92 	char			*client_address;
93 	unsigned int		version;
94 	unsigned int		minorversion;
95 	char			*fscache_uniq;
96 	bool			need_mount;
97 
98 	struct {
99 		struct sockaddr_storage	address;
100 		size_t			addrlen;
101 		char			*hostname;
102 		u32			version;
103 		int			port;
104 		unsigned short		protocol;
105 	} mount_server;
106 
107 	struct {
108 		struct sockaddr_storage	address;
109 		size_t			addrlen;
110 		char			*hostname;
111 		char			*export_path;
112 		int			port;
113 		unsigned short		protocol;
114 	} nfs_server;
115 
116 	struct security_mnt_opts lsm_opts;
117 	struct net		*net;
118 };
119 
120 /* mount_clnt.c */
121 struct nfs_mount_request {
122 	struct sockaddr		*sap;
123 	size_t			salen;
124 	char			*hostname;
125 	char			*dirpath;
126 	u32			version;
127 	unsigned short		protocol;
128 	struct nfs_fh		*fh;
129 	int			noresvport;
130 	unsigned int		*auth_flav_len;
131 	rpc_authflavor_t	*auth_flavs;
132 	struct net		*net;
133 };
134 
135 struct nfs_mount_info {
136 	void (*fill_super)(struct super_block *, struct nfs_mount_info *);
137 	int (*set_security)(struct super_block *, struct dentry *, struct nfs_mount_info *);
138 	struct nfs_parsed_mount_data *parsed;
139 	struct nfs_clone_mount *cloned;
140 	struct nfs_fh *mntfh;
141 };
142 
143 extern int nfs_mount(struct nfs_mount_request *info);
144 extern void nfs_umount(const struct nfs_mount_request *info);
145 
146 /* client.c */
147 extern const struct rpc_program nfs_program;
148 extern void nfs_clients_init(struct net *net);
149 extern struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *);
150 int nfs_create_rpc_client(struct nfs_client *, const struct rpc_timeout *, rpc_authflavor_t);
151 struct nfs_client *nfs_get_client(const struct nfs_client_initdata *,
152 				  const struct rpc_timeout *, const char *,
153 				  rpc_authflavor_t);
154 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *, struct nfs_fattr *);
155 void nfs_server_insert_lists(struct nfs_server *);
156 void nfs_server_remove_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 int nfs4_update_server(struct nfs_server *server, const char *hostname,
178 					struct sockaddr *sap, size_t salen,
179 					struct net *net);
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 					     u32 minor_version,
193 					     rpc_authflavor_t au_flavor);
194 extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
195 						struct inode *);
196 extern struct nfs_client *nfs3_set_ds_client(struct nfs_client *mds_clp,
197 			const struct sockaddr *ds_addr, int ds_addrlen,
198 			int ds_proto, unsigned int ds_timeo,
199 			unsigned int ds_retrans, rpc_authflavor_t au_flavor);
200 #ifdef CONFIG_PROC_FS
201 extern int __init nfs_fs_proc_init(void);
202 extern void nfs_fs_proc_exit(void);
203 extern int nfs_fs_proc_net_init(struct net *net);
204 extern void nfs_fs_proc_net_exit(struct net *net);
205 #else
206 static inline int nfs_fs_proc_net_init(struct net *net)
207 {
208 	return 0;
209 }
210 static inline void nfs_fs_proc_net_exit(struct net *net)
211 {
212 }
213 static inline int nfs_fs_proc_init(void)
214 {
215 	return 0;
216 }
217 static inline void nfs_fs_proc_exit(void)
218 {
219 }
220 #endif
221 
222 #ifdef CONFIG_NFS_V4_1
223 int nfs_sockaddr_match_ipaddr(const struct sockaddr *, const struct sockaddr *);
224 #endif
225 
226 /* callback_xdr.c */
227 extern struct svc_version nfs4_callback_version1;
228 extern struct svc_version nfs4_callback_version4;
229 
230 struct nfs_pageio_descriptor;
231 /* pagelist.c */
232 extern int __init nfs_init_nfspagecache(void);
233 extern void nfs_destroy_nfspagecache(void);
234 extern int __init nfs_init_readpagecache(void);
235 extern void nfs_destroy_readpagecache(void);
236 extern int __init nfs_init_writepagecache(void);
237 extern void nfs_destroy_writepagecache(void);
238 
239 extern int __init nfs_init_directcache(void);
240 extern void nfs_destroy_directcache(void);
241 extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
242 			      struct nfs_pgio_header *hdr,
243 			      void (*release)(struct nfs_pgio_header *hdr));
244 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
245 int nfs_iocounter_wait(struct nfs_io_counter *c);
246 
247 extern const struct nfs_pageio_ops nfs_pgio_rw_ops;
248 struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *);
249 void nfs_pgio_header_free(struct nfs_pgio_header *);
250 void nfs_pgio_data_destroy(struct nfs_pgio_header *);
251 int nfs_generic_pgio(struct nfs_pageio_descriptor *, struct nfs_pgio_header *);
252 int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
253 		      struct rpc_cred *cred, const struct nfs_rpc_ops *rpc_ops,
254 		      const struct rpc_call_ops *call_ops, int how, int flags);
255 void nfs_free_request(struct nfs_page *req);
256 struct nfs_pgio_mirror *
257 nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc);
258 
259 static inline void nfs_iocounter_init(struct nfs_io_counter *c)
260 {
261 	c->flags = 0;
262 	atomic_set(&c->io_count, 0);
263 }
264 
265 static inline bool nfs_pgio_has_mirroring(struct nfs_pageio_descriptor *desc)
266 {
267 	WARN_ON_ONCE(desc->pg_mirror_count < 1);
268 	return desc->pg_mirror_count > 1;
269 }
270 
271 /* nfs2xdr.c */
272 extern struct rpc_procinfo nfs_procedures[];
273 extern int nfs2_decode_dirent(struct xdr_stream *,
274 				struct nfs_entry *, int);
275 
276 /* nfs3xdr.c */
277 extern struct rpc_procinfo nfs3_procedures[];
278 extern int nfs3_decode_dirent(struct xdr_stream *,
279 				struct nfs_entry *, int);
280 
281 /* nfs4xdr.c */
282 #if IS_ENABLED(CONFIG_NFS_V4)
283 extern int nfs4_decode_dirent(struct xdr_stream *,
284 				struct nfs_entry *, int);
285 #endif
286 #ifdef CONFIG_NFS_V4_1
287 extern const u32 nfs41_maxread_overhead;
288 extern const u32 nfs41_maxwrite_overhead;
289 extern const u32 nfs41_maxgetdevinfo_overhead;
290 #endif
291 
292 /* nfs4proc.c */
293 #if IS_ENABLED(CONFIG_NFS_V4)
294 extern struct rpc_procinfo nfs4_procedures[];
295 #endif
296 
297 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
298 extern struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags);
299 static inline void nfs4_label_free(struct nfs4_label *label)
300 {
301 	if (label) {
302 		kfree(label->label);
303 		kfree(label);
304 	}
305 	return;
306 }
307 
308 static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
309 {
310 	if (nfs_server_capable(&nfsi->vfs_inode, NFS_CAP_SECURITY_LABEL))
311 		nfsi->cache_validity |= NFS_INO_INVALID_LABEL;
312 }
313 #else
314 static inline struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags) { return NULL; }
315 static inline void nfs4_label_free(void *label) {}
316 static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
317 {
318 }
319 #endif /* CONFIG_NFS_V4_SECURITY_LABEL */
320 
321 /* proc.c */
322 void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
323 extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
324 			   const struct rpc_timeout *timeparms,
325 			   const char *ip_addr);
326 
327 /* dir.c */
328 extern void nfs_force_use_readdirplus(struct inode *dir);
329 extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
330 					    struct shrink_control *sc);
331 extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
332 					   struct shrink_control *sc);
333 struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
334 int nfs_create(struct inode *, struct dentry *, umode_t, bool);
335 int nfs_mkdir(struct inode *, struct dentry *, umode_t);
336 int nfs_rmdir(struct inode *, struct dentry *);
337 int nfs_unlink(struct inode *, struct dentry *);
338 int nfs_symlink(struct inode *, struct dentry *, const char *);
339 int nfs_link(struct dentry *, struct inode *, struct dentry *);
340 int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
341 int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
342 
343 /* file.c */
344 int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
345 loff_t nfs_file_llseek(struct file *, loff_t, int);
346 int nfs_file_flush(struct file *, fl_owner_t);
347 ssize_t nfs_file_read(struct kiocb *, struct iov_iter *);
348 ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
349 			     size_t, unsigned int);
350 int nfs_file_mmap(struct file *, struct vm_area_struct *);
351 ssize_t nfs_file_write(struct kiocb *, struct iov_iter *);
352 int nfs_file_release(struct inode *, struct file *);
353 int nfs_lock(struct file *, int, struct file_lock *);
354 int nfs_flock(struct file *, int, struct file_lock *);
355 int nfs_check_flags(int);
356 
357 /* inode.c */
358 extern struct workqueue_struct *nfsiod_workqueue;
359 extern struct inode *nfs_alloc_inode(struct super_block *sb);
360 extern void nfs_destroy_inode(struct inode *);
361 extern int nfs_write_inode(struct inode *, struct writeback_control *);
362 extern int nfs_drop_inode(struct inode *);
363 extern void nfs_clear_inode(struct inode *);
364 extern void nfs_evict_inode(struct inode *);
365 void nfs_zap_acl_cache(struct inode *inode);
366 extern int nfs_wait_bit_killable(struct wait_bit_key *key);
367 
368 /* super.c */
369 extern const struct super_operations nfs_sops;
370 extern struct file_system_type nfs_fs_type;
371 extern struct file_system_type nfs_xdev_fs_type;
372 #if IS_ENABLED(CONFIG_NFS_V4)
373 extern struct file_system_type nfs4_xdev_fs_type;
374 extern struct file_system_type nfs4_referral_fs_type;
375 #endif
376 bool nfs_auth_info_match(const struct nfs_auth_info *, rpc_authflavor_t);
377 struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
378 			struct nfs_subversion *);
379 void nfs_initialise_sb(struct super_block *);
380 int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
381 int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
382 struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
383 				   struct nfs_mount_info *, struct nfs_subversion *);
384 struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
385 struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
386 		const char *, struct nfs_mount_info *);
387 void nfs_kill_super(struct super_block *);
388 void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
389 
390 extern struct rpc_stat nfs_rpcstat;
391 
392 extern int __init register_nfs_fs(void);
393 extern void __exit unregister_nfs_fs(void);
394 extern bool nfs_sb_active(struct super_block *sb);
395 extern void nfs_sb_deactive(struct super_block *sb);
396 
397 /* namespace.c */
398 #define NFS_PATH_CANONICAL 1
399 extern char *nfs_path(char **p, struct dentry *dentry,
400 		      char *buffer, ssize_t buflen, unsigned flags);
401 extern struct vfsmount *nfs_d_automount(struct path *path);
402 struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
403 			      struct nfs_fh *, struct nfs_fattr *);
404 struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
405 				 struct nfs_fattr *, rpc_authflavor_t);
406 
407 /* getroot.c */
408 extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
409 				   const char *);
410 #if IS_ENABLED(CONFIG_NFS_V4)
411 extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
412 				    const char *);
413 
414 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool);
415 #endif
416 
417 struct nfs_pgio_completion_ops;
418 /* read.c */
419 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
420 			struct inode *inode, bool force_mds,
421 			const struct nfs_pgio_completion_ops *compl_ops);
422 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
423 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
424 
425 /* super.c */
426 void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
427 void nfs_umount_begin(struct super_block *);
428 int  nfs_statfs(struct dentry *, struct kstatfs *);
429 int  nfs_show_options(struct seq_file *, struct dentry *);
430 int  nfs_show_devname(struct seq_file *, struct dentry *);
431 int  nfs_show_path(struct seq_file *, struct dentry *);
432 int  nfs_show_stats(struct seq_file *, struct dentry *);
433 int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
434 
435 /* write.c */
436 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
437 			struct inode *inode, int ioflags, bool force_mds,
438 			const struct nfs_pgio_completion_ops *compl_ops);
439 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
440 extern void nfs_commit_free(struct nfs_commit_data *p);
441 extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
442 extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
443 extern int nfs_initiate_commit(struct rpc_clnt *clnt,
444 			       struct nfs_commit_data *data,
445 			       const struct nfs_rpc_ops *nfs_ops,
446 			       const struct rpc_call_ops *call_ops,
447 			       int how, int flags);
448 extern void nfs_init_commit(struct nfs_commit_data *data,
449 			    struct list_head *head,
450 			    struct pnfs_layout_segment *lseg,
451 			    struct nfs_commit_info *cinfo);
452 int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
453 			 struct nfs_commit_info *cinfo, int max);
454 unsigned long nfs_reqs_to_commit(struct nfs_commit_info *);
455 int nfs_scan_commit(struct inode *inode, struct list_head *dst,
456 		    struct nfs_commit_info *cinfo);
457 void nfs_mark_request_commit(struct nfs_page *req,
458 			     struct pnfs_layout_segment *lseg,
459 			     struct nfs_commit_info *cinfo,
460 			     u32 ds_commit_idx);
461 int nfs_write_need_commit(struct nfs_pgio_header *);
462 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
463 			    int how, struct nfs_commit_info *cinfo);
464 void nfs_retry_commit(struct list_head *page_list,
465 		      struct pnfs_layout_segment *lseg,
466 		      struct nfs_commit_info *cinfo,
467 		      u32 ds_commit_idx);
468 void nfs_commitdata_release(struct nfs_commit_data *data);
469 void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
470 				 struct nfs_commit_info *cinfo);
471 void nfs_request_remove_commit_list(struct nfs_page *req,
472 				    struct nfs_commit_info *cinfo);
473 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
474 		    struct inode *inode,
475 		    struct nfs_direct_req *dreq);
476 int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
477 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
478 void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio);
479 
480 #ifdef CONFIG_MIGRATION
481 extern int nfs_migrate_page(struct address_space *,
482 		struct page *, struct page *, enum migrate_mode);
483 #else
484 #define nfs_migrate_page NULL
485 #endif
486 
487 /* unlink.c */
488 extern struct rpc_task *
489 nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
490 		 struct dentry *old_dentry, struct dentry *new_dentry,
491 		 void (*complete)(struct rpc_task *, struct nfs_renamedata *));
492 extern int nfs_sillyrename(struct inode *dir, struct dentry *dentry);
493 
494 /* direct.c */
495 void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
496 			      struct nfs_direct_req *dreq);
497 static inline void nfs_inode_dio_wait(struct inode *inode)
498 {
499 	inode_dio_wait(inode);
500 }
501 extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
502 extern void nfs_direct_set_resched_writes(struct nfs_direct_req *dreq);
503 
504 /* nfs4proc.c */
505 extern void __nfs4_read_done_cb(struct nfs_pgio_header *);
506 extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
507 			    const struct rpc_timeout *timeparms,
508 			    const char *ip_addr);
509 extern int nfs40_walk_client_list(struct nfs_client *clp,
510 				struct nfs_client **result,
511 				struct rpc_cred *cred);
512 extern int nfs41_walk_client_list(struct nfs_client *clp,
513 				struct nfs_client **result,
514 				struct rpc_cred *cred);
515 
516 static inline struct inode *nfs_igrab_and_active(struct inode *inode)
517 {
518 	inode = igrab(inode);
519 	if (inode != NULL && !nfs_sb_active(inode->i_sb)) {
520 		iput(inode);
521 		inode = NULL;
522 	}
523 	return inode;
524 }
525 
526 static inline void nfs_iput_and_deactive(struct inode *inode)
527 {
528 	if (inode != NULL) {
529 		struct super_block *sb = inode->i_sb;
530 
531 		iput(inode);
532 		nfs_sb_deactive(sb);
533 	}
534 }
535 
536 /*
537  * Determine the device name as a string
538  */
539 static inline char *nfs_devname(struct dentry *dentry,
540 				char *buffer, ssize_t buflen)
541 {
542 	char *dummy;
543 	return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
544 }
545 
546 /*
547  * Determine the actual block size (and log2 thereof)
548  */
549 static inline
550 unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
551 {
552 	/* make sure blocksize is a power of two */
553 	if ((bsize & (bsize - 1)) || nrbitsp) {
554 		unsigned char	nrbits;
555 
556 		for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
557 			;
558 		bsize = 1 << nrbits;
559 		if (nrbitsp)
560 			*nrbitsp = nrbits;
561 	}
562 
563 	return bsize;
564 }
565 
566 /*
567  * Calculate the number of 512byte blocks used.
568  */
569 static inline blkcnt_t nfs_calc_block_size(u64 tsize)
570 {
571 	blkcnt_t used = (tsize + 511) >> 9;
572 	return (used > ULONG_MAX) ? ULONG_MAX : used;
573 }
574 
575 /*
576  * Compute and set NFS server blocksize
577  */
578 static inline
579 unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
580 {
581 	if (bsize < NFS_MIN_FILE_IO_SIZE)
582 		bsize = NFS_DEF_FILE_IO_SIZE;
583 	else if (bsize >= NFS_MAX_FILE_IO_SIZE)
584 		bsize = NFS_MAX_FILE_IO_SIZE;
585 
586 	return nfs_block_bits(bsize, nrbitsp);
587 }
588 
589 /*
590  * Determine the maximum file size for a superblock
591  */
592 static inline
593 void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
594 {
595 	sb->s_maxbytes = (loff_t)maxfilesize;
596 	if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
597 		sb->s_maxbytes = MAX_LFS_FILESIZE;
598 }
599 
600 /*
601  * Record the page as unstable and mark its inode as dirty.
602  */
603 static inline
604 void nfs_mark_page_unstable(struct page *page)
605 {
606 	struct inode *inode = page_file_mapping(page)->host;
607 
608 	inc_zone_page_state(page, NR_UNSTABLE_NFS);
609 	inc_bdi_stat(inode_to_bdi(inode), BDI_RECLAIMABLE);
610 	 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
611 }
612 
613 /*
614  * Determine the number of bytes of data the page contains
615  */
616 static inline
617 unsigned int nfs_page_length(struct page *page)
618 {
619 	loff_t i_size = i_size_read(page_file_mapping(page)->host);
620 
621 	if (i_size > 0) {
622 		pgoff_t page_index = page_file_index(page);
623 		pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
624 		if (page_index < end_index)
625 			return PAGE_CACHE_SIZE;
626 		if (page_index == end_index)
627 			return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
628 	}
629 	return 0;
630 }
631 
632 /*
633  * Convert a umode to a dirent->d_type
634  */
635 static inline
636 unsigned char nfs_umode_to_dtype(umode_t mode)
637 {
638 	return (mode >> 12) & 15;
639 }
640 
641 /*
642  * Determine the number of pages in an array of length 'len' and
643  * with a base offset of 'base'
644  */
645 static inline
646 unsigned int nfs_page_array_len(unsigned int base, size_t len)
647 {
648 	return ((unsigned long)len + (unsigned long)base +
649 		PAGE_SIZE - 1) >> PAGE_SHIFT;
650 }
651 
652 /*
653  * Convert a struct timespec into a 64-bit change attribute
654  *
655  * This does approximately the same thing as timespec_to_ns(),
656  * but for calculation efficiency, we multiply the seconds by
657  * 1024*1024*1024.
658  */
659 static inline
660 u64 nfs_timespec_to_change_attr(const struct timespec *ts)
661 {
662 	return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
663 }
664 
665 #ifdef CONFIG_CRC32
666 /**
667  * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
668  * @fh - pointer to filehandle
669  *
670  * returns a crc32 hash for the filehandle that is compatible with
671  * the one displayed by "wireshark".
672  */
673 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
674 {
675 	return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
676 }
677 #else
678 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
679 {
680 	return 0;
681 }
682 #endif
683