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nfs: use generic posix ACL infrastructure for v3 Posix ACLs
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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