include/linux/nfs_fs.h

   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 for number of transports to different server IPs
  45  */
  46 #define NFS_MAX_TRANSPORTS 16
  47
  48 /*
  49  * These are the default flags for swap requests
  50  */
  51 #define NFS_RPC_SWAPFLAGS               (RPC_TASK_SWAPPER|RPC_TASK_ROOTCREDS)
  52
  53 /*
  54  * Size of the NFS directory verifier
  55  */
  56 #define NFS_DIR_VERIFIER_SIZE           2
  57
  58 /*
  59  * NFSv3/v4 Access mode cache entry
  60  */
  61 struct nfs_access_entry {
  62         struct rb_node          rb_node;
  63         struct list_head        lru;
  64         const struct cred *     cred;
  65         __u32                   mask;
  66         struct rcu_head         rcu_head;
  67 };
  68
  69 struct nfs_lock_context {
  70         refcount_t count;
  71         struct list_head list;
  72         struct nfs_open_context *open_context;
  73         fl_owner_t lockowner;
  74         atomic_t io_count;
  75         struct rcu_head rcu_head;
  76 };
  77
  78 struct nfs4_state;
  79 struct nfs_open_context {
  80         struct nfs_lock_context lock_context;
  81         fl_owner_t flock_owner;
  82         struct dentry *dentry;
  83         const struct cred *cred;
  84         struct rpc_cred *ll_cred;       /* low-level cred - use to check for expiry */
  85         struct nfs4_state *state;
  86         fmode_t mode;
  87
  88         unsigned long flags;
  89 #define NFS_CONTEXT_RESEND_WRITES       (1)
  90 #define NFS_CONTEXT_BAD                 (2)
  91 #define NFS_CONTEXT_UNLOCK      (3)
  92 #define NFS_CONTEXT_FILE_OPEN           (4)
  93         int error;
  94
  95         struct list_head list;
  96         struct nfs4_threshold   *mdsthreshold;
  97         struct rcu_head rcu_head;
  98 };
  99
 100 struct nfs_open_dir_context {
 101         struct list_head list;
 102         unsigned long attr_gencount;
 103         __be32  verf[NFS_DIR_VERIFIER_SIZE];
 104         __u64 dir_cookie;
 105         __u64 dup_cookie;
 106         signed char duped;
 107 };
 108
 109 /*
 110  * NFSv4 delegation
 111  */
 112 struct nfs_delegation;
 113
 114 struct posix_acl;
 115
 116 struct nfs4_xattr_cache;
 117
 118 /*
 119  * nfs fs inode data in memory
 120  */
 121 struct nfs_inode {
 122         /*
 123          * The 64bit 'inode number'
 124          */
 125         __u64 fileid;
 126
 127         /*
 128          * NFS file handle
 129          */
 130         struct nfs_fh           fh;
 131
 132         /*
 133          * Various flags
 134          */
 135         unsigned long           flags;                  /* atomic bit ops */
 136         unsigned long           cache_validity;         /* bit mask */
 137
 138         /*
 139          * read_cache_jiffies is when we started read-caching this inode.
 140          * attrtimeo is for how long the cached information is assumed
 141          * to be valid. A successful attribute revalidation doubles
 142          * attrtimeo (up to acregmax/acdirmax), a failure resets it to
 143          * acregmin/acdirmin.
 144          *
 145          * We need to revalidate the cached attrs for this inode if
 146          *
 147          *      jiffies - read_cache_jiffies >= attrtimeo
 148          *
 149          * Please note the comparison is greater than or equal
 150          * so that zero timeout values can be specified.
 151          */
 152         unsigned long           read_cache_jiffies;
 153         unsigned long           attrtimeo;
 154         unsigned long           attrtimeo_timestamp;
 155
 156         unsigned long           attr_gencount;
 157         /* "Generation counter" for the attribute cache. This is
 158          * bumped whenever we update the metadata on the
 159          * server.
 160          */
 161         unsigned long           cache_change_attribute;
 162
 163         struct rb_root          access_cache;
 164         struct list_head        access_cache_entry_lru;
 165         struct list_head        access_cache_inode_lru;
 166
 167         /*
 168          * This is the cookie verifier used for NFSv3 readdir
 169          * operations
 170          */
 171         __be32                  cookieverf[NFS_DIR_VERIFIER_SIZE];
 172
 173         atomic_long_t           nrequests;
 174         struct nfs_mds_commit_info commit_info;
 175
 176         /* Open contexts for shared mmap writes */
 177         struct list_head        open_files;
 178
 179         /* Readers: in-flight sillydelete RPC calls */
 180         /* Writers: rmdir */
 181         struct rw_semaphore     rmdir_sem;
 182         struct mutex            commit_mutex;
 183
 184         /* track last access to cached pages */
 185         unsigned long           page_index;
 186
 187 #if IS_ENABLED(CONFIG_NFS_V4)
 188         struct nfs4_cached_acl  *nfs4_acl;
 189         /* NFSv4 state */
 190         struct list_head        open_states;
 191         struct nfs_delegation __rcu *delegation;
 192         struct rw_semaphore     rwsem;
 193
 194         /* pNFS layout information */
 195         struct pnfs_layout_hdr *layout;
 196 #endif /* CONFIG_NFS_V4*/
 197         /* how many bytes have been written/read and how many bytes queued up */
 198         __u64 write_io;
 199         __u64 read_io;
 200 #ifdef CONFIG_NFS_FSCACHE
 201         struct fscache_cookie   *fscache;
 202 #endif
 203         struct inode            vfs_inode;
 204
 205 #ifdef CONFIG_NFS_V4_2
 206         struct nfs4_xattr_cache *xattr_cache;
 207 #endif
 208 };
 209
 210 struct nfs4_copy_state {
 211         struct list_head        copies;
 212         struct list_head        src_copies;
 213         nfs4_stateid            stateid;
 214         struct completion       completion;
 215         uint64_t                count;
 216         struct nfs_writeverf    verf;
 217         int                     error;
 218         int                     flags;
 219         struct nfs4_state       *parent_src_state;
 220         struct nfs4_state       *parent_dst_state;
 221 };
 222
 223 /*
 224  * Access bit flags
 225  */
 226 #define NFS_ACCESS_READ        0x0001
 227 #define NFS_ACCESS_LOOKUP      0x0002
 228 #define NFS_ACCESS_MODIFY      0x0004
 229 #define NFS_ACCESS_EXTEND      0x0008
 230 #define NFS_ACCESS_DELETE      0x0010
 231 #define NFS_ACCESS_EXECUTE     0x0020
 232 #define NFS_ACCESS_XAREAD      0x0040
 233 #define NFS_ACCESS_XAWRITE     0x0080
 234 #define NFS_ACCESS_XALIST      0x0100
 235
 236 /*
 237  * Cache validity bit flags
 238  */
 239 #define NFS_INO_INVALID_DATA    BIT(1)          /* cached data is invalid */
 240 #define NFS_INO_INVALID_ATIME   BIT(2)          /* cached atime is invalid */
 241 #define NFS_INO_INVALID_ACCESS  BIT(3)          /* cached access cred invalid */
 242 #define NFS_INO_INVALID_ACL     BIT(4)          /* cached acls are invalid */
 243 #define NFS_INO_REVAL_PAGECACHE BIT(5)          /* must revalidate pagecache */
 244 #define NFS_INO_REVAL_FORCED    BIT(6)          /* force revalidation ignoring a delegation */
 245 #define NFS_INO_INVALID_LABEL   BIT(7)          /* cached label is invalid */
 246 #define NFS_INO_INVALID_CHANGE  BIT(8)          /* cached change is invalid */
 247 #define NFS_INO_INVALID_CTIME   BIT(9)          /* cached ctime is invalid */
 248 #define NFS_INO_INVALID_MTIME   BIT(10)         /* cached mtime is invalid */
 249 #define NFS_INO_INVALID_SIZE    BIT(11)         /* cached size is invalid */
 250 #define NFS_INO_INVALID_OTHER   BIT(12)         /* other attrs are invalid */
 251 #define NFS_INO_DATA_INVAL_DEFER        \
 252                                 BIT(13)         /* Deferred cache invalidation */
 253 #define NFS_INO_INVALID_BLOCKS  BIT(14)         /* cached blocks are invalid */
 254 #define NFS_INO_INVALID_XATTR   BIT(15)         /* xattrs are invalid */
 255 #define NFS_INO_INVALID_NLINK   BIT(16)         /* cached nlinks is invalid */
 256 #define NFS_INO_INVALID_MODE    BIT(17)         /* cached mode is invalid */
 257
 258 #define NFS_INO_INVALID_ATTR    (NFS_INO_INVALID_CHANGE \
 259                 | NFS_INO_INVALID_CTIME \
 260                 | NFS_INO_INVALID_MTIME \
 261                 | NFS_INO_INVALID_SIZE \
 262                 | NFS_INO_INVALID_NLINK \
 263                 | NFS_INO_INVALID_MODE \
 264                 | NFS_INO_INVALID_OTHER)        /* inode metadata is invalid */
 265
 266 /*
 267  * Bit offsets in flags field
 268  */
 269 #define NFS_INO_ADVISE_RDPLUS   (0)             /* advise readdirplus */
 270 #define NFS_INO_STALE           (1)             /* possible stale inode */
 271 #define NFS_INO_ACL_LRU_SET     (2)             /* Inode is on the LRU list */
 272 #define NFS_INO_INVALIDATING    (3)             /* inode is being invalidated */
 273 #define NFS_INO_FSCACHE         (5)             /* inode can be cached by FS-Cache */
 274 #define NFS_INO_FSCACHE_LOCK    (6)             /* FS-Cache cookie management lock */
 275 #define NFS_INO_LAYOUTCOMMIT    (9)             /* layoutcommit required */
 276 #define NFS_INO_LAYOUTCOMMITTING (10)           /* layoutcommit inflight */
 277 #define NFS_INO_LAYOUTSTATS     (11)            /* layoutstats inflight */
 278 #define NFS_INO_ODIRECT         (12)            /* I/O setting is O_DIRECT */
 279
 280 static inline struct nfs_inode *NFS_I(const struct inode *inode)
 281 {
 282         return container_of(inode, struct nfs_inode, vfs_inode);
 283 }
 284
 285 static inline struct nfs_server *NFS_SB(const struct super_block *s)
 286 {
 287         return (struct nfs_server *)(s->s_fs_info);
 288 }
 289
 290 static inline struct nfs_fh *NFS_FH(const struct inode *inode)
 291 {
 292         return &NFS_I(inode)->fh;
 293 }
 294
 295 static inline struct nfs_server *NFS_SERVER(const struct inode *inode)
 296 {
 297         return NFS_SB(inode->i_sb);
 298 }
 299
 300 static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode)
 301 {
 302         return NFS_SERVER(inode)->client;
 303 }
 304
 305 static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode)
 306 {
 307         return NFS_SERVER(inode)->nfs_client->rpc_ops;
 308 }
 309
 310 static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode)
 311 {
 312         struct nfs_server *nfss = NFS_SERVER(inode);
 313         return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin;
 314 }
 315
 316 static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode)
 317 {
 318         struct nfs_server *nfss = NFS_SERVER(inode);
 319         return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax;
 320 }
 321
 322 static inline int NFS_STALE(const struct inode *inode)
 323 {
 324         return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
 325 }
 326
 327 static inline struct fscache_cookie *nfs_i_fscache(struct inode *inode)
 328 {
 329 #ifdef CONFIG_NFS_FSCACHE
 330         return NFS_I(inode)->fscache;
 331 #else
 332         return NULL;
 333 #endif
 334 }
 335
 336 static inline __u64 NFS_FILEID(const struct inode *inode)
 337 {
 338         return NFS_I(inode)->fileid;
 339 }
 340
 341 static inline void set_nfs_fileid(struct inode *inode, __u64 fileid)
 342 {
 343         NFS_I(inode)->fileid = fileid;
 344 }
 345
 346 static inline void nfs_mark_for_revalidate(struct inode *inode)
 347 {
 348         struct nfs_inode *nfsi = NFS_I(inode);
 349
 350         spin_lock(&inode->i_lock);
 351         nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE
 352                 | NFS_INO_INVALID_ACCESS
 353                 | NFS_INO_INVALID_ACL
 354                 | NFS_INO_INVALID_CHANGE
 355                 | NFS_INO_INVALID_CTIME;
 356         if (S_ISDIR(inode->i_mode))
 357                 nfsi->cache_validity |= NFS_INO_INVALID_DATA;
 358         spin_unlock(&inode->i_lock);
 359 }
 360
 361 static inline int nfs_server_capable(struct inode *inode, int cap)
 362 {
 363         return NFS_SERVER(inode)->caps & cap;
 364 }
 365
 366 /**
 367  * nfs_save_change_attribute - Returns the inode attribute change cookie
 368  * @dir - pointer to parent directory inode
 369  * The "cache change attribute" is updated when we need to revalidate
 370  * our dentry cache after a directory was seen to change on the server.
 371  */
 372 static inline unsigned long nfs_save_change_attribute(struct inode *dir)
 373 {
 374         return NFS_I(dir)->cache_change_attribute;
 375 }
 376
 377 /*
 378  * linux/fs/nfs/inode.c
 379  */
 380 extern int nfs_sync_mapping(struct address_space *mapping);
 381 extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping);
 382 extern void nfs_zap_caches(struct inode *);
 383 extern void nfs_set_inode_stale(struct inode *inode);
 384 extern void nfs_invalidate_atime(struct inode *);
 385 extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
 386                                 struct nfs_fattr *, struct nfs4_label *);
 387 struct inode *nfs_ilookup(struct super_block *sb, struct nfs_fattr *, struct nfs_fh *);
 388 extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
 389 extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
 390 extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
 391 extern int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr);
 392 extern int nfs_getattr(struct user_namespace *, const struct path *,
 393                        struct kstat *, u32, unsigned int);
 394 extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *);
 395 extern void nfs_access_set_mask(struct nfs_access_entry *, u32);
 396 extern int nfs_permission(struct user_namespace *, struct inode *, int);
 397 extern int nfs_open(struct inode *, struct file *);
 398 extern int nfs_attribute_cache_expired(struct inode *inode);
 399 extern int nfs_revalidate_inode(struct inode *inode, unsigned long flags);
 400 extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
 401 extern int nfs_clear_invalid_mapping(struct address_space *mapping);
 402 extern bool nfs_mapping_need_revalidate_inode(struct inode *inode);
 403 extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
 404 extern int nfs_revalidate_mapping_rcu(struct inode *inode);
 405 extern int nfs_setattr(struct user_namespace *, struct dentry *, struct iattr *);
 406 extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *);
 407 extern void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
 408                                 struct nfs4_label *label);
 409 extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
 410 extern void put_nfs_open_context(struct nfs_open_context *ctx);
 411 extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode);
 412 extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode, struct file *filp);
 413 extern void nfs_inode_attach_open_context(struct nfs_open_context *ctx);
 414 extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);
 415 extern void nfs_file_clear_open_context(struct file *flip);
 416 extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx);
 417 extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx);
 418 extern u64 nfs_compat_user_ino64(u64 fileid);
 419 extern void nfs_fattr_init(struct nfs_fattr *fattr);
 420 extern void nfs_fattr_set_barrier(struct nfs_fattr *fattr);
 421 extern unsigned long nfs_inc_attr_generation_counter(void);
 422
 423 extern struct nfs_fattr *nfs_alloc_fattr(void);
 424
 425 static inline void nfs_free_fattr(const struct nfs_fattr *fattr)
 426 {
 427         kfree(fattr);
 428 }
 429
 430 extern struct nfs_fh *nfs_alloc_fhandle(void);
 431
 432 static inline void nfs_free_fhandle(const struct nfs_fh *fh)
 433 {
 434         kfree(fh);
 435 }
 436
 437 #ifdef NFS_DEBUG
 438 extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh);
 439 static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
 440 {
 441         return _nfs_display_fhandle_hash(fh);
 442 }
 443 extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption);
 444 #define nfs_display_fhandle(fh, caption)                        \
 445         do {                                                    \
 446                 if (unlikely(nfs_debug & NFSDBG_FACILITY))      \
 447                         _nfs_display_fhandle(fh, caption);      \
 448         } while (0)
 449 #else
 450 static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
 451 {
 452         return 0;
 453 }
 454 static inline void nfs_display_fhandle(const struct nfs_fh *fh,
 455                                        const char *caption)
 456 {
 457 }
 458 #endif
 459
 460 /*
 461  * linux/fs/nfs/nfsroot.c
 462  */
 463 extern int  nfs_root_data(char **root_device, char **root_data); /*__init*/
 464 /* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
 465 extern __be32 root_nfs_parse_addr(char *name); /*__init*/
 466
 467 /*
 468  * linux/fs/nfs/file.c
 469  */
 470 extern const struct file_operations nfs_file_operations;
 471 #if IS_ENABLED(CONFIG_NFS_V4)
 472 extern const struct file_operations nfs4_file_operations;
 473 #endif /* CONFIG_NFS_V4 */
 474 extern const struct address_space_operations nfs_file_aops;
 475 extern const struct address_space_operations nfs_dir_aops;
 476
 477 static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
 478 {
 479         return filp->private_data;
 480 }
 481
 482 static inline const struct cred *nfs_file_cred(struct file *file)
 483 {
 484         if (file != NULL) {
 485                 struct nfs_open_context *ctx =
 486                         nfs_file_open_context(file);
 487                 if (ctx)
 488                         return ctx->cred;
 489         }
 490         return NULL;
 491 }
 492
 493 /*
 494  * linux/fs/nfs/direct.c
 495  */
 496 extern ssize_t nfs_direct_IO(struct kiocb *, struct iov_iter *);
 497 extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
 498                         struct iov_iter *iter);
 499 extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
 500                         struct iov_iter *iter);
 501
 502 /*
 503  * linux/fs/nfs/dir.c
 504  */
 505 extern const struct file_operations nfs_dir_operations;
 506 extern const struct dentry_operations nfs_dentry_operations;
 507
 508 extern void nfs_force_lookup_revalidate(struct inode *dir);
 509 extern void nfs_set_verifier(struct dentry * dentry, unsigned long verf);
 510 #if IS_ENABLED(CONFIG_NFS_V4)
 511 extern void nfs_clear_verifier_delegated(struct inode *inode);
 512 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
 513 extern struct dentry *nfs_add_or_obtain(struct dentry *dentry,
 514                         struct nfs_fh *fh, struct nfs_fattr *fattr,
 515                         struct nfs4_label *label);
 516 extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh,
 517                         struct nfs_fattr *fattr, struct nfs4_label *label);
 518 extern int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags);
 519 extern void nfs_access_zap_cache(struct inode *inode);
 520 extern int nfs_access_get_cached(struct inode *inode, const struct cred *cred, struct nfs_access_entry *res,
 521                                  bool may_block);
 522
 523 /*
 524  * linux/fs/nfs/symlink.c
 525  */
 526 extern const struct inode_operations nfs_symlink_inode_operations;
 527
 528 /*
 529  * linux/fs/nfs/sysctl.c
 530  */
 531 #ifdef CONFIG_SYSCTL
 532 extern int nfs_register_sysctl(void);
 533 extern void nfs_unregister_sysctl(void);
 534 #else
 535 #define nfs_register_sysctl() 0
 536 #define nfs_unregister_sysctl() do { } while(0)
 537 #endif
 538
 539 /*
 540  * linux/fs/nfs/namespace.c
 541  */
 542 extern const struct inode_operations nfs_mountpoint_inode_operations;
 543 extern const struct inode_operations nfs_referral_inode_operations;
 544 extern int nfs_mountpoint_expiry_timeout;
 545 extern void nfs_release_automount_timer(void);
 546
 547 /*
 548  * linux/fs/nfs/unlink.c
 549  */
 550 extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);
 551
 552 /*
 553  * linux/fs/nfs/write.c
 554  */
 555 extern int  nfs_congestion_kb;
 556 extern int  nfs_writepage(struct page *page, struct writeback_control *wbc);
 557 extern int  nfs_writepages(struct address_space *, struct writeback_control *);
 558 extern int  nfs_flush_incompatible(struct file *file, struct page *page);
 559 extern int  nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
 560
 561 /*
 562  * Try to write back everything synchronously (but check the
 563  * return value!)
 564  */
 565 extern int nfs_sync_inode(struct inode *inode);
 566 extern int nfs_wb_all(struct inode *inode);
 567 extern int nfs_wb_page(struct inode *inode, struct page *page);
 568 extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);
 569 extern int  nfs_commit_inode(struct inode *, int);
 570 extern struct nfs_commit_data *nfs_commitdata_alloc(bool never_fail);
 571 extern void nfs_commit_free(struct nfs_commit_data *data);
 572
 573 static inline int
 574 nfs_have_writebacks(struct inode *inode)
 575 {
 576         return atomic_long_read(&NFS_I(inode)->nrequests) != 0;
 577 }
 578
 579 /*
 580  * linux/fs/nfs/read.c
 581  */
 582 extern int  nfs_readpage(struct file *, struct page *);
 583 extern int  nfs_readpages(struct file *, struct address_space *,
 584                 struct list_head *, unsigned);
 585
 586 /*
 587  * inline functions
 588  */
 589
 590 static inline loff_t nfs_size_to_loff_t(__u64 size)
 591 {
 592         return min_t(u64, size, OFFSET_MAX);
 593 }
 594
 595 static inline ino_t
 596 nfs_fileid_to_ino_t(u64 fileid)
 597 {
 598         ino_t ino = (ino_t) fileid;
 599         if (sizeof(ino_t) < sizeof(u64))
 600                 ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;
 601         return ino;
 602 }
 603
 604 #define NFS_JUKEBOX_RETRY_TIME (5 * HZ)
 605
 606
 607 # undef ifdebug
 608 # ifdef NFS_DEBUG
 609 #  define ifdebug(fac)          if (unlikely(nfs_debug & NFSDBG_##fac))
 610 #  define NFS_IFDEBUG(x)        x
 611 # else
 612 #  define ifdebug(fac)          if (0)
 613 #  define NFS_IFDEBUG(x)
 614 # endif
 615 #endif