Free Electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
/*
 * NFS internal definitions
 */

#include "nfs4_fs.h"
#include <linux/mount.h>
#include <linux/security.h>
#include <linux/crc32.h>
#include <linux/nfs_page.h>

#define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)

struct nfs_string;

/* Maximum number of readahead requests
 * FIXME: this should really be a sysctl so that users may tune it to suit
 *        their needs. People that do NFS over a slow network, might for
 *        instance want to reduce it to something closer to 1 for improved
 *        interactive response.
 */
#define NFS_MAX_READAHEAD	(RPC_DEF_SLOT_TABLE - 1)

static inline void nfs_attr_check_mountpoint(struct super_block *parent, struct nfs_fattr *fattr)
{
	if (!nfs_fsid_equal(&NFS_SB(parent)->fsid, &fattr->fsid))
		fattr->valid |= NFS_ATTR_FATTR_MOUNTPOINT;
}

static inline int nfs_attr_use_mounted_on_fileid(struct nfs_fattr *fattr)
{
	if (((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) == 0) ||
	    (((fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT) == 0) &&
	     ((fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) == 0)))
		return 0;
	return 1;
}

struct nfs_clone_mount {
	const struct super_block *sb;
	const struct dentry *dentry;
	struct nfs_fh *fh;
	struct nfs_fattr *fattr;
	char *hostname;
	char *mnt_path;
	struct sockaddr *addr;
	size_t addrlen;
	rpc_authflavor_t authflavor;
};

/*
 * Note: RFC 1813 doesn't limit the number of auth flavors that
 * a server can return, so make something up.
 */
#define NFS_MAX_SECFLAVORS	(12)

/*
 * Value used if the user did not specify a port value.
 */
#define NFS_UNSPEC_PORT		(-1)

/*
 * Maximum number of pages that readdir can use for creating
 * a vmapped array of pages.
 */
#define NFS_MAX_READDIR_PAGES 8

struct nfs_client_initdata {
	unsigned long init_flags;
	const char *hostname;
	const struct sockaddr *addr;
	size_t addrlen;
	struct nfs_subversion *nfs_mod;
	int proto;
	u32 minorversion;
	struct net *net;
};

/*
 * In-kernel mount arguments
 */
struct nfs_parsed_mount_data {
	int			flags;
	unsigned int		rsize, wsize;
	unsigned int		timeo, retrans;
	unsigned int		acregmin, acregmax,
				acdirmin, acdirmax;
	unsigned int		namlen;
	unsigned int		options;
	unsigned int		bsize;
	struct nfs_auth_info	auth_info;
	rpc_authflavor_t	selected_flavor;
	char			*client_address;
	unsigned int		version;
	unsigned int		minorversion;
	char			*fscache_uniq;
	bool			need_mount;

	struct {
		struct sockaddr_storage	address;
		size_t			addrlen;
		char			*hostname;
		u32			version;
		int			port;
		unsigned short		protocol;
	} mount_server;

	struct {
		struct sockaddr_storage	address;
		size_t			addrlen;
		char			*hostname;
		char			*export_path;
		int			port;
		unsigned short		protocol;
	} nfs_server;

	struct security_mnt_opts lsm_opts;
	struct net		*net;
};

/* mount_clnt.c */
struct nfs_mount_request {
	struct sockaddr		*sap;
	size_t			salen;
	char			*hostname;
	char			*dirpath;
	u32			version;
	unsigned short		protocol;
	struct nfs_fh		*fh;
	int			noresvport;
	unsigned int		*auth_flav_len;
	rpc_authflavor_t	*auth_flavs;
	struct net		*net;
};

struct nfs_mount_info {
	void (*fill_super)(struct super_block *, struct nfs_mount_info *);
	int (*set_security)(struct super_block *, struct dentry *, struct nfs_mount_info *);
	struct nfs_parsed_mount_data *parsed;
	struct nfs_clone_mount *cloned;
	struct nfs_fh *mntfh;
};

extern int nfs_mount(struct nfs_mount_request *info);
extern void nfs_umount(const struct nfs_mount_request *info);

/* client.c */
extern const struct rpc_program nfs_program;
extern void nfs_clients_init(struct net *net);
extern struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *);
int nfs_create_rpc_client(struct nfs_client *, const struct rpc_timeout *, rpc_authflavor_t);
struct nfs_client *nfs_get_client(const struct nfs_client_initdata *,
				  const struct rpc_timeout *, const char *,
				  rpc_authflavor_t);
int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *, struct nfs_fattr *);
void nfs_server_insert_lists(struct nfs_server *);
void nfs_server_remove_lists(struct nfs_server *);
void nfs_init_timeout_values(struct rpc_timeout *, int, unsigned int, unsigned int);
int nfs_init_server_rpcclient(struct nfs_server *, const struct rpc_timeout *t,
		rpc_authflavor_t);
struct nfs_server *nfs_alloc_server(void);
void nfs_server_copy_userdata(struct nfs_server *, struct nfs_server *);

extern void nfs_cleanup_cb_ident_idr(struct net *);
extern void nfs_put_client(struct nfs_client *);
extern void nfs_free_client(struct nfs_client *);
extern struct nfs_client *nfs4_find_client_ident(struct net *, int);
extern struct nfs_client *
nfs4_find_client_sessionid(struct net *, const struct sockaddr *,
				struct nfs4_sessionid *, u32);
extern struct nfs_server *nfs_create_server(struct nfs_mount_info *,
					struct nfs_subversion *);
extern struct nfs_server *nfs4_create_server(
					struct nfs_mount_info *,
					struct nfs_subversion *);
extern struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *,
						      struct nfs_fh *);
extern int nfs4_update_server(struct nfs_server *server, const char *hostname,
					struct sockaddr *sap, size_t salen,
					struct net *net);
extern void nfs_free_server(struct nfs_server *server);
extern struct nfs_server *nfs_clone_server(struct nfs_server *,
					   struct nfs_fh *,
					   struct nfs_fattr *,
					   rpc_authflavor_t);
extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
					     const struct sockaddr *ds_addr,
					     int ds_addrlen, int ds_proto,
					     unsigned int ds_timeo,
					     unsigned int ds_retrans,
					     u32 minor_version,
					     rpc_authflavor_t au_flavor);
extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
						struct inode *);
extern struct nfs_client *nfs3_set_ds_client(struct nfs_client *mds_clp,
			const struct sockaddr *ds_addr, int ds_addrlen,
			int ds_proto, unsigned int ds_timeo,
			unsigned int ds_retrans, rpc_authflavor_t au_flavor);
#ifdef CONFIG_PROC_FS
extern int __init nfs_fs_proc_init(void);
extern void nfs_fs_proc_exit(void);
extern int nfs_fs_proc_net_init(struct net *net);
extern void nfs_fs_proc_net_exit(struct net *net);
#else
static inline int nfs_fs_proc_net_init(struct net *net)
{
	return 0;
}
static inline void nfs_fs_proc_net_exit(struct net *net)
{
}
static inline int nfs_fs_proc_init(void)
{
	return 0;
}
static inline void nfs_fs_proc_exit(void)
{
}
#endif

#ifdef CONFIG_NFS_V4_1
int nfs_sockaddr_match_ipaddr(const struct sockaddr *, const struct sockaddr *);
#endif

/* callback_xdr.c */
extern struct svc_version nfs4_callback_version1;
extern struct svc_version nfs4_callback_version4;

struct nfs_pageio_descriptor;
/* pagelist.c */
extern int __init nfs_init_nfspagecache(void);
extern void nfs_destroy_nfspagecache(void);
extern int __init nfs_init_readpagecache(void);
extern void nfs_destroy_readpagecache(void);
extern int __init nfs_init_writepagecache(void);
extern void nfs_destroy_writepagecache(void);

extern int __init nfs_init_directcache(void);
extern void nfs_destroy_directcache(void);
extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
			      struct nfs_pgio_header *hdr,
			      void (*release)(struct nfs_pgio_header *hdr));
void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
int nfs_iocounter_wait(struct nfs_io_counter *c);

extern const struct nfs_pageio_ops nfs_pgio_rw_ops;
struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *);
void nfs_pgio_header_free(struct nfs_pgio_header *);
void nfs_pgio_data_destroy(struct nfs_pgio_header *);
int nfs_generic_pgio(struct nfs_pageio_descriptor *, struct nfs_pgio_header *);
int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
		      struct rpc_cred *cred, const struct nfs_rpc_ops *rpc_ops,
		      const struct rpc_call_ops *call_ops, int how, int flags);
void nfs_free_request(struct nfs_page *req);
struct nfs_pgio_mirror *
nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc);

static inline void nfs_iocounter_init(struct nfs_io_counter *c)
{
	c->flags = 0;
	atomic_set(&c->io_count, 0);
}

static inline bool nfs_pgio_has_mirroring(struct nfs_pageio_descriptor *desc)
{
	WARN_ON_ONCE(desc->pg_mirror_count < 1);
	return desc->pg_mirror_count > 1;
}

/* nfs2xdr.c */
extern struct rpc_procinfo nfs_procedures[];
extern int nfs2_decode_dirent(struct xdr_stream *,
				struct nfs_entry *, int);

/* nfs3xdr.c */
extern struct rpc_procinfo nfs3_procedures[];
extern int nfs3_decode_dirent(struct xdr_stream *,
				struct nfs_entry *, int);

/* nfs4xdr.c */
#if IS_ENABLED(CONFIG_NFS_V4)
extern int nfs4_decode_dirent(struct xdr_stream *,
				struct nfs_entry *, int);
#endif
#ifdef CONFIG_NFS_V4_1
extern const u32 nfs41_maxread_overhead;
extern const u32 nfs41_maxwrite_overhead;
extern const u32 nfs41_maxgetdevinfo_overhead;
#endif

/* nfs4proc.c */
#if IS_ENABLED(CONFIG_NFS_V4)
extern struct rpc_procinfo nfs4_procedures[];
#endif

#ifdef CONFIG_NFS_V4_SECURITY_LABEL
extern struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags);
static inline void nfs4_label_free(struct nfs4_label *label)
{
	if (label) {
		kfree(label->label);
		kfree(label);
	}
	return;
}

static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
{
	if (nfs_server_capable(&nfsi->vfs_inode, NFS_CAP_SECURITY_LABEL))
		nfsi->cache_validity |= NFS_INO_INVALID_LABEL;
}
#else
static inline struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags) { return NULL; }
static inline void nfs4_label_free(void *label) {}
static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
{
}
#endif /* CONFIG_NFS_V4_SECURITY_LABEL */

/* proc.c */
void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
			   const struct rpc_timeout *timeparms,
			   const char *ip_addr);

/* dir.c */
extern void nfs_force_use_readdirplus(struct inode *dir);
extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
					    struct shrink_control *sc);
extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
					   struct shrink_control *sc);
struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
int nfs_create(struct inode *, struct dentry *, umode_t, bool);
int nfs_mkdir(struct inode *, struct dentry *, umode_t);
int nfs_rmdir(struct inode *, struct dentry *);
int nfs_unlink(struct inode *, struct dentry *);
int nfs_symlink(struct inode *, struct dentry *, const char *);
int nfs_link(struct dentry *, struct inode *, struct dentry *);
int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);

/* file.c */
int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
loff_t nfs_file_llseek(struct file *, loff_t, int);
int nfs_file_flush(struct file *, fl_owner_t);
ssize_t nfs_file_read(struct kiocb *, struct iov_iter *);
ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
			     size_t, unsigned int);
int nfs_file_mmap(struct file *, struct vm_area_struct *);
ssize_t nfs_file_write(struct kiocb *, struct iov_iter *);
int nfs_file_release(struct inode *, struct file *);
int nfs_lock(struct file *, int, struct file_lock *);
int nfs_flock(struct file *, int, struct file_lock *);
int nfs_check_flags(int);

/* inode.c */
extern struct workqueue_struct *nfsiod_workqueue;
extern struct inode *nfs_alloc_inode(struct super_block *sb);
extern void nfs_destroy_inode(struct inode *);
extern int nfs_write_inode(struct inode *, struct writeback_control *);
extern int nfs_drop_inode(struct inode *);
extern void nfs_clear_inode(struct inode *);
extern void nfs_evict_inode(struct inode *);
void nfs_zap_acl_cache(struct inode *inode);
extern int nfs_wait_bit_killable(struct wait_bit_key *key);

/* super.c */
extern const struct super_operations nfs_sops;
extern struct file_system_type nfs_fs_type;
extern struct file_system_type nfs_xdev_fs_type;
#if IS_ENABLED(CONFIG_NFS_V4)
extern struct file_system_type nfs4_xdev_fs_type;
extern struct file_system_type nfs4_referral_fs_type;
#endif
bool nfs_auth_info_match(const struct nfs_auth_info *, rpc_authflavor_t);
struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
			struct nfs_subversion *);
void nfs_initialise_sb(struct super_block *);
int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
				   struct nfs_mount_info *, struct nfs_subversion *);
struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
		const char *, struct nfs_mount_info *);
void nfs_kill_super(struct super_block *);
void nfs_fill_super(struct super_block *, struct nfs_mount_info *);

extern struct rpc_stat nfs_rpcstat;

extern int __init register_nfs_fs(void);
extern void __exit unregister_nfs_fs(void);
extern bool nfs_sb_active(struct super_block *sb);
extern void nfs_sb_deactive(struct super_block *sb);

/* namespace.c */
#define NFS_PATH_CANONICAL 1
extern char *nfs_path(char **p, struct dentry *dentry,
		      char *buffer, ssize_t buflen, unsigned flags);
extern struct vfsmount *nfs_d_automount(struct path *path);
struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
			      struct nfs_fh *, struct nfs_fattr *);
struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
				 struct nfs_fattr *, rpc_authflavor_t);

/* getroot.c */
extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
				   const char *);
#if IS_ENABLED(CONFIG_NFS_V4)
extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
				    const char *);

extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool);
#endif

struct nfs_pgio_completion_ops;
/* read.c */
extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
			struct inode *inode, bool force_mds,
			const struct nfs_pgio_completion_ops *compl_ops);
extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);

/* super.c */
void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
void nfs_umount_begin(struct super_block *);
int  nfs_statfs(struct dentry *, struct kstatfs *);
int  nfs_show_options(struct seq_file *, struct dentry *);
int  nfs_show_devname(struct seq_file *, struct dentry *);
int  nfs_show_path(struct seq_file *, struct dentry *);
int  nfs_show_stats(struct seq_file *, struct dentry *);
int nfs_remount(struct super_block *sb, int *flags, char *raw_data);

/* write.c */
extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
			struct inode *inode, int ioflags, bool force_mds,
			const struct nfs_pgio_completion_ops *compl_ops);
extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
extern void nfs_commit_free(struct nfs_commit_data *p);
extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
extern int nfs_initiate_commit(struct rpc_clnt *clnt,
			       struct nfs_commit_data *data,
			       const struct nfs_rpc_ops *nfs_ops,
			       const struct rpc_call_ops *call_ops,
			       int how, int flags);
extern void nfs_init_commit(struct nfs_commit_data *data,
			    struct list_head *head,
			    struct pnfs_layout_segment *lseg,
			    struct nfs_commit_info *cinfo);
int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
			 struct nfs_commit_info *cinfo, int max);
unsigned long nfs_reqs_to_commit(struct nfs_commit_info *);
int nfs_scan_commit(struct inode *inode, struct list_head *dst,
		    struct nfs_commit_info *cinfo);
void nfs_mark_request_commit(struct nfs_page *req,
			     struct pnfs_layout_segment *lseg,
			     struct nfs_commit_info *cinfo,
			     u32 ds_commit_idx);
int nfs_write_need_commit(struct nfs_pgio_header *);
void nfs_writeback_update_inode(struct nfs_pgio_header *hdr);
int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
			    int how, struct nfs_commit_info *cinfo);
void nfs_retry_commit(struct list_head *page_list,
		      struct pnfs_layout_segment *lseg,
		      struct nfs_commit_info *cinfo,
		      u32 ds_commit_idx);
void nfs_commitdata_release(struct nfs_commit_data *data);
void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
				 struct nfs_commit_info *cinfo);
void nfs_request_remove_commit_list(struct nfs_page *req,
				    struct nfs_commit_info *cinfo);
void nfs_init_cinfo(struct nfs_commit_info *cinfo,
		    struct inode *inode,
		    struct nfs_direct_req *dreq);
int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio);

#ifdef CONFIG_MIGRATION
extern int nfs_migrate_page(struct address_space *,
		struct page *, struct page *, enum migrate_mode);
#else
#define nfs_migrate_page NULL
#endif

/* unlink.c */
extern struct rpc_task *
nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
		 struct dentry *old_dentry, struct dentry *new_dentry,
		 void (*complete)(struct rpc_task *, struct nfs_renamedata *));
extern int nfs_sillyrename(struct inode *dir, struct dentry *dentry);

/* direct.c */
void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
			      struct nfs_direct_req *dreq);
static inline void nfs_inode_dio_wait(struct inode *inode)
{
	inode_dio_wait(inode);
}
extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
extern void nfs_direct_set_resched_writes(struct nfs_direct_req *dreq);

/* nfs4proc.c */
extern void __nfs4_read_done_cb(struct nfs_pgio_header *);
extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
			    const struct rpc_timeout *timeparms,
			    const char *ip_addr);
extern int nfs40_walk_client_list(struct nfs_client *clp,
				struct nfs_client **result,
				struct rpc_cred *cred);
extern int nfs41_walk_client_list(struct nfs_client *clp,
				struct nfs_client **result,
				struct rpc_cred *cred);

static inline struct inode *nfs_igrab_and_active(struct inode *inode)
{
	inode = igrab(inode);
	if (inode != NULL && !nfs_sb_active(inode->i_sb)) {
		iput(inode);
		inode = NULL;
	}
	return inode;
}

static inline void nfs_iput_and_deactive(struct inode *inode)
{
	if (inode != NULL) {
		struct super_block *sb = inode->i_sb;

		iput(inode);
		nfs_sb_deactive(sb);
	}
}

/*
 * Determine the device name as a string
 */
static inline char *nfs_devname(struct dentry *dentry,
				char *buffer, ssize_t buflen)
{
	char *dummy;
	return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
}

/*
 * Determine the actual block size (and log2 thereof)
 */
static inline
unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
{
	/* make sure blocksize is a power of two */
	if ((bsize & (bsize - 1)) || nrbitsp) {
		unsigned char	nrbits;

		for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
			;
		bsize = 1 << nrbits;
		if (nrbitsp)
			*nrbitsp = nrbits;
	}

	return bsize;
}

/*
 * Calculate the number of 512byte blocks used.
 */
static inline blkcnt_t nfs_calc_block_size(u64 tsize)
{
	blkcnt_t used = (tsize + 511) >> 9;
	return (used > ULONG_MAX) ? ULONG_MAX : used;
}

/*
 * Compute and set NFS server blocksize
 */
static inline
unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
{
	if (bsize < NFS_MIN_FILE_IO_SIZE)
		bsize = NFS_DEF_FILE_IO_SIZE;
	else if (bsize >= NFS_MAX_FILE_IO_SIZE)
		bsize = NFS_MAX_FILE_IO_SIZE;

	return nfs_block_bits(bsize, nrbitsp);
}

/*
 * Determine the maximum file size for a superblock
 */
static inline
void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
{
	sb->s_maxbytes = (loff_t)maxfilesize;
	if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
		sb->s_maxbytes = MAX_LFS_FILESIZE;
}

/*
 * Record the page as unstable and mark its inode as dirty.
 */
static inline
void nfs_mark_page_unstable(struct page *page)
{
	struct inode *inode = page_file_mapping(page)->host;

	inc_zone_page_state(page, NR_UNSTABLE_NFS);
	inc_bdi_stat(inode_to_bdi(inode), BDI_RECLAIMABLE);
	 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
}

/*
 * Determine the number of bytes of data the page contains
 */
static inline
unsigned int nfs_page_length(struct page *page)
{
	loff_t i_size = i_size_read(page_file_mapping(page)->host);

	if (i_size > 0) {
		pgoff_t page_index = page_file_index(page);
		pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
		if (page_index < end_index)
			return PAGE_CACHE_SIZE;
		if (page_index == end_index)
			return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
	}
	return 0;
}

/*
 * Convert a umode to a dirent->d_type
 */
static inline
unsigned char nfs_umode_to_dtype(umode_t mode)
{
	return (mode >> 12) & 15;
}

/*
 * Determine the number of pages in an array of length 'len' and
 * with a base offset of 'base'
 */
static inline
unsigned int nfs_page_array_len(unsigned int base, size_t len)
{
	return ((unsigned long)len + (unsigned long)base +
		PAGE_SIZE - 1) >> PAGE_SHIFT;
}

/*
 * Convert a struct timespec into a 64-bit change attribute
 *
 * This does approximately the same thing as timespec_to_ns(),
 * but for calculation efficiency, we multiply the seconds by
 * 1024*1024*1024.
 */
static inline
u64 nfs_timespec_to_change_attr(const struct timespec *ts)
{
	return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
}

#ifdef CONFIG_CRC32
/**
 * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
 * @fh - pointer to filehandle
 *
 * returns a crc32 hash for the filehandle that is compatible with
 * the one displayed by "wireshark".
 */
static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
{
	return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
}
#else
static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
{
	return 0;
}
#endif