root/include/linux/nfs_fs.h

INCLUDED FROM

DEFINITIONS

1. NFS_I
2. NFS_SB
3. NFS_FH
4. NFS_SERVER
5. NFS_CLIENT
6. NFS_PROTO
7. NFS_MINATTRTIMEO
8. NFS_MAXATTRTIMEO
9. NFS_STALE
10. nfs_i_fscache
11. NFS_FILEID
12. set_nfs_fileid
13. nfs_mark_for_revalidate
14. nfs_server_capable
15. nfs_set_verifier
16. nfs_save_change_attribute
17. nfs_verify_change_attribute
18. nfs_free_fattr
19. nfs_free_fhandle
20. nfs_display_fhandle_hash
21. nfs_display_fhandle_hash
22. nfs_display_fhandle
23. nfs_file_open_context
24. nfs_file_cred
25. nfs_have_writebacks
26. nfs_size_to_loff_t
27. nfs_fileid_to_ino_t

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *  linux/include/linux/nfs_fs.h
   4  *
   5  *  Copyright (C) 1992  Rick Sladkey
   6  *
   7  *  OS-specific nfs filesystem definitions and declarations
   8  */
   9 #ifndef _LINUX_NFS_FS_H
  10 #define _LINUX_NFS_FS_H
  11 
  12 #include <uapi/linux/nfs_fs.h>
  13 
  14 
  15 /*
  16  * Enable dprintk() debugging support for nfs client.
  17  */
  18 #ifdef CONFIG_NFS_DEBUG
  19 # define NFS_DEBUG
  20 #endif
  21 
  22 #include <linux/in.h>
  23 #include <linux/mm.h>
  24 #include <linux/pagemap.h>
  25 #include <linux/rbtree.h>
  26 #include <linux/refcount.h>
  27 #include <linux/rwsem.h>
  28 #include <linux/wait.h>
  29 
  30 #include <linux/sunrpc/debug.h>
  31 #include <linux/sunrpc/auth.h>
  32 #include <linux/sunrpc/clnt.h>
  33 
  34 #include <linux/nfs.h>
  35 #include <linux/nfs2.h>
  36 #include <linux/nfs3.h>
  37 #include <linux/nfs4.h>
  38 #include <linux/nfs_xdr.h>
  39 #include <linux/nfs_fs_sb.h>
  40 
  41 #include <linux/mempool.h>
  42 
  43 /*
  44  * These are the default flags for swap requests
  45  */
  46 #define NFS_RPC_SWAPFLAGS               (RPC_TASK_SWAPPER|RPC_TASK_ROOTCREDS)
  47 
  48 /*
  49  * NFSv3/v4 Access mode cache entry
  50  */
  51 struct nfs_access_entry {
  52         struct rb_node          rb_node;
  53         struct list_head        lru;
  54         const struct cred *     cred;
  55         __u32                   mask;
  56         struct rcu_head         rcu_head;
  57 };
  58 
  59 struct nfs_lock_context {
  60         refcount_t count;
  61         struct list_head list;
  62         struct nfs_open_context *open_context;
  63         fl_owner_t lockowner;
  64         atomic_t io_count;
  65         struct rcu_head rcu_head;
  66 };
  67 
  68 struct nfs4_state;
  69 struct nfs_open_context {
  70         struct nfs_lock_context lock_context;
  71         fl_owner_t flock_owner;
  72         struct dentry *dentry;
  73         const struct cred *cred;
  74         struct rpc_cred *ll_cred;       /* low-level cred - use to check for expiry */
  75         struct nfs4_state *state;
  76         fmode_t mode;
  77 
  78         unsigned long flags;
  79 #define NFS_CONTEXT_RESEND_WRITES       (1)
  80 #define NFS_CONTEXT_BAD                 (2)
  81 #define NFS_CONTEXT_UNLOCK      (3)
  82         int error;
  83 
  84         struct list_head list;
  85         struct nfs4_threshold   *mdsthreshold;
  86         struct rcu_head rcu_head;
  87 };
  88 
  89 struct nfs_open_dir_context {
  90         struct list_head list;
  91         const struct cred *cred;
  92         unsigned long attr_gencount;
  93         __u64 dir_cookie;
  94         __u64 dup_cookie;
  95         signed char duped;
  96 };
  97 
  98 /*
  99  * NFSv4 delegation
 100  */
 101 struct nfs_delegation;
 102 
 103 struct posix_acl;
 104 
 105 /*
 106  * nfs fs inode data in memory
 107  */
 108 struct nfs_inode {
 109         /*
 110          * The 64bit 'inode number'
 111          */
 112         __u64 fileid;
 113 
 114         /*
 115          * NFS file handle
 116          */
 117         struct nfs_fh           fh;
 118 
 119         /*
 120          * Various flags
 121          */
 122         unsigned long           flags;                  /* atomic bit ops */
 123         unsigned long           cache_validity;         /* bit mask */
 124 
 125         /*
 126          * read_cache_jiffies is when we started read-caching this inode.
 127          * attrtimeo is for how long the cached information is assumed
 128          * to be valid. A successful attribute revalidation doubles
 129          * attrtimeo (up to acregmax/acdirmax), a failure resets it to
 130          * acregmin/acdirmin.
 131          *
 132          * We need to revalidate the cached attrs for this inode if
 133          *
 134          *      jiffies - read_cache_jiffies >= attrtimeo
 135          *
 136          * Please note the comparison is greater than or equal
 137          * so that zero timeout values can be specified.
 138          */
 139         unsigned long           read_cache_jiffies;
 140         unsigned long           attrtimeo;
 141         unsigned long           attrtimeo_timestamp;
 142 
 143         unsigned long           attr_gencount;
 144         /* "Generation counter" for the attribute cache. This is
 145          * bumped whenever we update the metadata on the
 146          * server.
 147          */
 148         unsigned long           cache_change_attribute;
 149 
 150         struct rb_root          access_cache;
 151         struct list_head        access_cache_entry_lru;
 152         struct list_head        access_cache_inode_lru;
 153 
 154         /*
 155          * This is the cookie verifier used for NFSv3 readdir
 156          * operations
 157          */
 158         __be32                  cookieverf[2];
 159 
 160         atomic_long_t           nrequests;
 161         struct nfs_mds_commit_info commit_info;
 162 
 163         /* Open contexts for shared mmap writes */
 164         struct list_head        open_files;
 165 
 166         /* Readers: in-flight sillydelete RPC calls */
 167         /* Writers: rmdir */
 168         struct rw_semaphore     rmdir_sem;
 169         struct mutex            commit_mutex;
 170 
 171 #if IS_ENABLED(CONFIG_NFS_V4)
 172         struct nfs4_cached_acl  *nfs4_acl;
 173         /* NFSv4 state */
 174         struct list_head        open_states;
 175         struct nfs_delegation __rcu *delegation;
 176         struct rw_semaphore     rwsem;
 177 
 178         /* pNFS layout information */
 179         struct pnfs_layout_hdr *layout;
 180 #endif /* CONFIG_NFS_V4*/
 181         /* how many bytes have been written/read and how many bytes queued up */
 182         __u64 write_io;
 183         __u64 read_io;
 184 #ifdef CONFIG_NFS_FSCACHE
 185         struct fscache_cookie   *fscache;
 186 #endif
 187         struct inode            vfs_inode;
 188 };
 189 
 190 struct nfs4_copy_state {
 191         struct list_head        copies;
 192         nfs4_stateid            stateid;
 193         struct completion       completion;
 194         uint64_t                count;
 195         struct nfs_writeverf    verf;
 196         int                     error;
 197         int                     flags;
 198         struct nfs4_state       *parent_state;
 199 };
 200 
 201 /*
 202  * Access bit flags
 203  */
 204 #define NFS_ACCESS_READ        0x0001
 205 #define NFS_ACCESS_LOOKUP      0x0002
 206 #define NFS_ACCESS_MODIFY      0x0004
 207 #define NFS_ACCESS_EXTEND      0x0008
 208 #define NFS_ACCESS_DELETE      0x0010
 209 #define NFS_ACCESS_EXECUTE     0x0020
 210 
 211 /*
 212  * Cache validity bit flags
 213  */
 214 #define NFS_INO_INVALID_DATA    BIT(1)          /* cached data is invalid */
 215 #define NFS_INO_INVALID_ATIME   BIT(2)          /* cached atime is invalid */
 216 #define NFS_INO_INVALID_ACCESS  BIT(3)          /* cached access cred invalid */
 217 #define NFS_INO_INVALID_ACL     BIT(4)          /* cached acls are invalid */
 218 #define NFS_INO_REVAL_PAGECACHE BIT(5)          /* must revalidate pagecache */
 219 #define NFS_INO_REVAL_FORCED    BIT(6)          /* force revalidation ignoring a delegation */
 220 #define NFS_INO_INVALID_LABEL   BIT(7)          /* cached label is invalid */
 221 #define NFS_INO_INVALID_CHANGE  BIT(8)          /* cached change is invalid */
 222 #define NFS_INO_INVALID_CTIME   BIT(9)          /* cached ctime is invalid */
 223 #define NFS_INO_INVALID_MTIME   BIT(10)         /* cached mtime is invalid */
 224 #define NFS_INO_INVALID_SIZE    BIT(11)         /* cached size is invalid */
 225 #define NFS_INO_INVALID_OTHER   BIT(12)         /* other attrs are invalid */
 226 #define NFS_INO_DATA_INVAL_DEFER        \
 227                                 BIT(13)         /* Deferred cache invalidation */
 228 
 229 #define NFS_INO_INVALID_ATTR    (NFS_INO_INVALID_CHANGE \
 230                 | NFS_INO_INVALID_CTIME \
 231                 | NFS_INO_INVALID_MTIME \
 232                 | NFS_INO_INVALID_SIZE \
 233                 | NFS_INO_INVALID_OTHER)        /* inode metadata is invalid */
 234 
 235 /*
 236  * Bit offsets in flags field
 237  */
 238 #define NFS_INO_ADVISE_RDPLUS   (0)             /* advise readdirplus */
 239 #define NFS_INO_STALE           (1)             /* possible stale inode */
 240 #define NFS_INO_ACL_LRU_SET     (2)             /* Inode is on the LRU list */
 241 #define NFS_INO_INVALIDATING    (3)             /* inode is being invalidated */
 242 #define NFS_INO_FSCACHE         (5)             /* inode can be cached by FS-Cache */
 243 #define NFS_INO_FSCACHE_LOCK    (6)             /* FS-Cache cookie management lock */
 244 #define NFS_INO_LAYOUTCOMMIT    (9)             /* layoutcommit required */
 245 #define NFS_INO_LAYOUTCOMMITTING (10)           /* layoutcommit inflight */
 246 #define NFS_INO_LAYOUTSTATS     (11)            /* layoutstats inflight */
 247 #define NFS_INO_ODIRECT         (12)            /* I/O setting is O_DIRECT */
 248 
 249 static inline struct nfs_inode *NFS_I(const struct inode *inode)
 250 {
 251         return container_of(inode, struct nfs_inode, vfs_inode);
 252 }
 253 
 254 static inline struct nfs_server *NFS_SB(const struct super_block *s)
 255 {
 256         return (struct nfs_server *)(s->s_fs_info);
 257 }
 258 
 259 static inline struct nfs_fh *NFS_FH(const struct inode *inode)
 260 {
 261         return &NFS_I(inode)->fh;
 262 }
 263 
 264 static inline struct nfs_server *NFS_SERVER(const struct inode *inode)
 265 {
 266         return NFS_SB(inode->i_sb);
 267 }
 268 
 269 static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode)
 270 {
 271         return NFS_SERVER(inode)->client;
 272 }
 273 
 274 static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode)
 275 {
 276         return NFS_SERVER(inode)->nfs_client->rpc_ops;
 277 }
 278 
 279 static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode)
 280 {
 281         struct nfs_server *nfss = NFS_SERVER(inode);
 282         return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin;
 283 }
 284 
 285 static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode)
 286 {
 287         struct nfs_server *nfss = NFS_SERVER(inode);
 288         return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax;
 289 }
 290 
 291 static inline int NFS_STALE(const struct inode *inode)
 292 {
 293         return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
 294 }
 295 
 296 static inline struct fscache_cookie *nfs_i_fscache(struct inode *inode)
 297 {
 298 #ifdef CONFIG_NFS_FSCACHE
 299         return NFS_I(inode)->fscache;
 300 #else
 301         return NULL;
 302 #endif
 303 }
 304 
 305 static inline __u64 NFS_FILEID(const struct inode *inode)
 306 {
 307         return NFS_I(inode)->fileid;
 308 }
 309 
 310 static inline void set_nfs_fileid(struct inode *inode, __u64 fileid)
 311 {
 312         NFS_I(inode)->fileid = fileid;
 313 }
 314 
 315 static inline void nfs_mark_for_revalidate(struct inode *inode)
 316 {
 317         struct nfs_inode *nfsi = NFS_I(inode);
 318 
 319         spin_lock(&inode->i_lock);
 320         nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE
 321                 | NFS_INO_INVALID_ACCESS
 322                 | NFS_INO_INVALID_ACL
 323                 | NFS_INO_INVALID_CHANGE
 324                 | NFS_INO_INVALID_CTIME;
 325         if (S_ISDIR(inode->i_mode))
 326                 nfsi->cache_validity |= NFS_INO_INVALID_DATA;
 327         spin_unlock(&inode->i_lock);
 328 }
 329 
 330 static inline int nfs_server_capable(struct inode *inode, int cap)
 331 {
 332         return NFS_SERVER(inode)->caps & cap;
 333 }
 334 
 335 static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
 336 {
 337         dentry->d_time = verf;
 338 }
 339 
 340 /**
 341  * nfs_save_change_attribute - Returns the inode attribute change cookie
 342  * @dir - pointer to parent directory inode
 343  * The "change attribute" is updated every time we finish an operation
 344  * that will result in a metadata change on the server.
 345  */
 346 static inline unsigned long nfs_save_change_attribute(struct inode *dir)
 347 {
 348         return NFS_I(dir)->cache_change_attribute;
 349 }
 350 
 351 /**
 352  * nfs_verify_change_attribute - Detects NFS remote directory changes
 353  * @dir - pointer to parent directory inode
 354  * @chattr - previously saved change attribute
 355  * Return "false" if the verifiers doesn't match the change attribute.
 356  * This would usually indicate that the directory contents have changed on
 357  * the server, and that any dentries need revalidating.
 358  */
 359 static inline int nfs_verify_change_attribute(struct inode *dir, unsigned long chattr)
 360 {
 361         return chattr == NFS_I(dir)->cache_change_attribute;
 362 }
 363 
 364 /*
 365  * linux/fs/nfs/inode.c
 366  */
 367 extern int nfs_sync_mapping(struct address_space *mapping);
 368 extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping);
 369 extern void nfs_zap_caches(struct inode *);
 370 extern void nfs_invalidate_atime(struct inode *);
 371 extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
 372                                 struct nfs_fattr *, struct nfs4_label *);
 373 struct inode *nfs_ilookup(struct super_block *sb, struct nfs_fattr *, struct nfs_fh *);
 374 extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
 375 extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
 376 extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
 377 extern int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr);
 378 extern int nfs_getattr(const struct path *, struct kstat *, u32, unsigned int);
 379 extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *);
 380 extern void nfs_access_set_mask(struct nfs_access_entry *, u32);
 381 extern int nfs_permission(struct inode *, int);
 382 extern int nfs_open(struct inode *, struct file *);
 383 extern int nfs_attribute_cache_expired(struct inode *inode);
 384 extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode);
 385 extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
 386 extern bool nfs_mapping_need_revalidate_inode(struct inode *inode);
 387 extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
 388 extern int nfs_revalidate_mapping_rcu(struct inode *inode);
 389 extern int nfs_setattr(struct dentry *, struct iattr *);
 390 extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *);
 391 extern void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
 392                                 struct nfs4_label *label);
 393 extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
 394 extern void put_nfs_open_context(struct nfs_open_context *ctx);
 395 extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode);
 396 extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode, struct file *filp);
 397 extern void nfs_inode_attach_open_context(struct nfs_open_context *ctx);
 398 extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);
 399 extern void nfs_file_clear_open_context(struct file *flip);
 400 extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx);
 401 extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx);
 402 extern u64 nfs_compat_user_ino64(u64 fileid);
 403 extern void nfs_fattr_init(struct nfs_fattr *fattr);
 404 extern void nfs_fattr_set_barrier(struct nfs_fattr *fattr);
 405 extern unsigned long nfs_inc_attr_generation_counter(void);
 406 
 407 extern struct nfs_fattr *nfs_alloc_fattr(void);
 408 
 409 static inline void nfs_free_fattr(const struct nfs_fattr *fattr)
 410 {
 411         kfree(fattr);
 412 }
 413 
 414 extern struct nfs_fh *nfs_alloc_fhandle(void);
 415 
 416 static inline void nfs_free_fhandle(const struct nfs_fh *fh)
 417 {
 418         kfree(fh);
 419 }
 420 
 421 #ifdef NFS_DEBUG
 422 extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh);
 423 static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
 424 {
 425         return _nfs_display_fhandle_hash(fh);
 426 }
 427 extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption);
 428 #define nfs_display_fhandle(fh, caption)                        \
 429         do {                                                    \
 430                 if (unlikely(nfs_debug & NFSDBG_FACILITY))      \
 431                         _nfs_display_fhandle(fh, caption);      \
 432         } while (0)
 433 #else
 434 static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
 435 {
 436         return 0;
 437 }
 438 static inline void nfs_display_fhandle(const struct nfs_fh *fh,
 439                                        const char *caption)
 440 {
 441 }
 442 #endif
 443 
 444 /*
 445  * linux/fs/nfs/nfsroot.c
 446  */
 447 extern int  nfs_root_data(char **root_device, char **root_data); /*__init*/
 448 /* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
 449 extern __be32 root_nfs_parse_addr(char *name); /*__init*/
 450 
 451 /*
 452  * linux/fs/nfs/file.c
 453  */
 454 extern const struct file_operations nfs_file_operations;
 455 #if IS_ENABLED(CONFIG_NFS_V4)
 456 extern const struct file_operations nfs4_file_operations;
 457 #endif /* CONFIG_NFS_V4 */
 458 extern const struct address_space_operations nfs_file_aops;
 459 extern const struct address_space_operations nfs_dir_aops;
 460 
 461 static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
 462 {
 463         return filp->private_data;
 464 }
 465 
 466 static inline const struct cred *nfs_file_cred(struct file *file)
 467 {
 468         if (file != NULL) {
 469                 struct nfs_open_context *ctx =
 470                         nfs_file_open_context(file);
 471                 if (ctx)
 472                         return ctx->cred;
 473         }
 474         return NULL;
 475 }
 476 
 477 /*
 478  * linux/fs/nfs/direct.c
 479  */
 480 extern ssize_t nfs_direct_IO(struct kiocb *, struct iov_iter *);
 481 extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
 482                         struct iov_iter *iter);
 483 extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
 484                         struct iov_iter *iter);
 485 
 486 /*
 487  * linux/fs/nfs/dir.c
 488  */
 489 extern const struct file_operations nfs_dir_operations;
 490 extern const struct dentry_operations nfs_dentry_operations;
 491 
 492 extern void nfs_force_lookup_revalidate(struct inode *dir);
 493 extern struct dentry *nfs_add_or_obtain(struct dentry *dentry,
 494                         struct nfs_fh *fh, struct nfs_fattr *fattr,
 495                         struct nfs4_label *label);
 496 extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh,
 497                         struct nfs_fattr *fattr, struct nfs4_label *label);
 498 extern int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags);
 499 extern void nfs_access_zap_cache(struct inode *inode);
 500 
 501 /*
 502  * linux/fs/nfs/symlink.c
 503  */
 504 extern const struct inode_operations nfs_symlink_inode_operations;
 505 
 506 /*
 507  * linux/fs/nfs/sysctl.c
 508  */
 509 #ifdef CONFIG_SYSCTL
 510 extern int nfs_register_sysctl(void);
 511 extern void nfs_unregister_sysctl(void);
 512 #else
 513 #define nfs_register_sysctl() 0
 514 #define nfs_unregister_sysctl() do { } while(0)
 515 #endif
 516 
 517 /*
 518  * linux/fs/nfs/namespace.c
 519  */
 520 extern const struct inode_operations nfs_mountpoint_inode_operations;
 521 extern const struct inode_operations nfs_referral_inode_operations;
 522 extern int nfs_mountpoint_expiry_timeout;
 523 extern void nfs_release_automount_timer(void);
 524 
 525 /*
 526  * linux/fs/nfs/unlink.c
 527  */
 528 extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);
 529 
 530 /*
 531  * linux/fs/nfs/write.c
 532  */
 533 extern int  nfs_congestion_kb;
 534 extern int  nfs_writepage(struct page *page, struct writeback_control *wbc);
 535 extern int  nfs_writepages(struct address_space *, struct writeback_control *);
 536 extern int  nfs_flush_incompatible(struct file *file, struct page *page);
 537 extern int  nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
 538 
 539 /*
 540  * Try to write back everything synchronously (but check the
 541  * return value!)
 542  */
 543 extern int nfs_sync_inode(struct inode *inode);
 544 extern int nfs_wb_all(struct inode *inode);
 545 extern int nfs_wb_page(struct inode *inode, struct page *page);
 546 extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);
 547 extern int  nfs_commit_inode(struct inode *, int);
 548 extern struct nfs_commit_data *nfs_commitdata_alloc(bool never_fail);
 549 extern void nfs_commit_free(struct nfs_commit_data *data);
 550 
 551 static inline int
 552 nfs_have_writebacks(struct inode *inode)
 553 {
 554         return atomic_long_read(&NFS_I(inode)->nrequests) != 0;
 555 }
 556 
 557 /*
 558  * linux/fs/nfs/read.c
 559  */
 560 extern int  nfs_readpage(struct file *, struct page *);
 561 extern int  nfs_readpages(struct file *, struct address_space *,
 562                 struct list_head *, unsigned);
 563 extern int  nfs_readpage_async(struct nfs_open_context *, struct inode *,
 564                                struct page *);
 565 
 566 /*
 567  * inline functions
 568  */
 569 
 570 static inline loff_t nfs_size_to_loff_t(__u64 size)
 571 {
 572         return min_t(u64, size, OFFSET_MAX);
 573 }
 574 
 575 static inline ino_t
 576 nfs_fileid_to_ino_t(u64 fileid)
 577 {
 578         ino_t ino = (ino_t) fileid;
 579         if (sizeof(ino_t) < sizeof(u64))
 580                 ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;
 581         return ino;
 582 }
 583 
 584 #define NFS_JUKEBOX_RETRY_TIME (5 * HZ)
 585 
 586 
 587 # undef ifdebug
 588 # ifdef NFS_DEBUG
 589 #  define ifdebug(fac)          if (unlikely(nfs_debug & NFSDBG_##fac))
 590 #  define NFS_IFDEBUG(x)        x
 591 # else
 592 #  define ifdebug(fac)          if (0)
 593 #  define NFS_IFDEBUG(x)
 594 # endif
 595 #endif