LXR linux/include/linux/nfs

   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 */
  61struct 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
  69struct 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
  78struct nfs4_state;
  79struct 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 __rcu *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
 100struct 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        pgoff_t page_index;
 107        signed char duped;
 108};
 109
 110/*
 111 * NFSv4 delegation
 112 */
 113struct nfs_delegation;
 114
 115struct posix_acl;
 116
 117struct nfs4_xattr_cache;
 118
 119/*
 120 * nfs fs inode data in memory
 121 */
 122struct nfs_inode {
 123        /*
 124         * The 64bit 'inode number'
 125         */
 126        __u64 fileid;
 127
 128        /*
 129         * NFS file handle
 130         */
 131        struct nfs_fh           fh;
 132
 133        /*
 134         * Various flags
 135         */
 136        unsigned long           flags;                  /* atomic bit ops */
 137        unsigned long           cache_validity;         /* bit mask */
 138
 139        /*
 140         * read_cache_jiffies is when we started read-caching this inode.
 141         * attrtimeo is for how long the cached information is assumed
 142         * to be valid. A successful attribute revalidation doubles
 143         * attrtimeo (up to acregmax/acdirmax), a failure resets it to
 144         * acregmin/acdirmin.
 145         *
 146         * We need to revalidate the cached attrs for this inode if
 147         *
 148         *      jiffies - read_cache_jiffies >= attrtimeo
 149         *
 150         * Please note the comparison is greater than or equal
 151         * so that zero timeout values can be specified.
 152         */
 153        unsigned long           read_cache_jiffies;
 154        unsigned long           attrtimeo;
 155        unsigned long           attrtimeo_timestamp;
 156
 157        unsigned long           attr_gencount;
 158
 159        struct rb_root          access_cache;
 160        struct list_head        access_cache_entry_lru;
 161        struct list_head        access_cache_inode_lru;
 162
 163        union {
 164                /* Directory */
 165                struct {
 166                        /* "Generation counter" for the attribute cache.
 167                         * This is bumped whenever we update the metadata
 168                         * on the server.
 169                         */
 170                        unsigned long   cache_change_attribute;
 171                        /*
 172                         * This is the cookie verifier used for NFSv3 readdir
 173                         * operations
 174                         */
 175                        __be32          cookieverf[NFS_DIR_VERIFIER_SIZE];
 176                        /* Readers: in-flight sillydelete RPC calls */
 177                        /* Writers: rmdir */
 178                        struct rw_semaphore     rmdir_sem;
 179                };
 180                /* Regular file */
 181                struct {
 182                        atomic_long_t   nrequests;
 183                        struct nfs_mds_commit_info commit_info;
 184                        struct mutex    commit_mutex;
 185                };
 186        };
 187
 188        /* Open contexts for shared mmap writes */
 189        struct list_head        open_files;
 190
 191#if IS_ENABLED(CONFIG_NFS_V4)
 192        struct nfs4_cached_acl  *nfs4_acl;
 193        /* NFSv4 state */
 194        struct list_head        open_states;
 195        struct nfs_delegation __rcu *delegation;
 196        struct rw_semaphore     rwsem;
 197
 198        /* pNFS layout information */
 199        struct pnfs_layout_hdr *layout;
 200#endif /* CONFIG_NFS_V4*/
 201        /* how many bytes have been written/read and how many bytes queued up */
 202        __u64 write_io;
 203        __u64 read_io;
 204#ifdef CONFIG_NFS_FSCACHE
 205        struct fscache_cookie   *fscache;
 206#endif
 207        struct inode            vfs_inode;
 208
 209#ifdef CONFIG_NFS_V4_2
 210        struct nfs4_xattr_cache *xattr_cache;
 211#endif
 212};
 213
 214struct nfs4_copy_state {
 215        struct list_head        copies;
 216        struct list_head        src_copies;
 217        nfs4_stateid            stateid;
 218        struct completion       completion;
 219        uint64_t                count;
 220        struct nfs_writeverf    verf;
 221        int                     error;
 222        int                     flags;
 223        struct nfs4_state       *parent_src_state;
 224        struct nfs4_state       *parent_dst_state;
 225};
 226
 227/*
 228 * Access bit flags
 229 */
 230#define NFS_ACCESS_READ        0x0001
 231#define NFS_ACCESS_LOOKUP      0x0002
 232#define NFS_ACCESS_MODIFY      0x0004
 233#define NFS_ACCESS_EXTEND      0x0008
 234#define NFS_ACCESS_DELETE      0x0010
 235#define NFS_ACCESS_EXECUTE     0x0020
 236#define NFS_ACCESS_XAREAD      0x0040
 237#define NFS_ACCESS_XAWRITE     0x0080
 238#define NFS_ACCESS_XALIST      0x0100
 239
 240/*
 241 * Cache validity bit flags
 242 */
 243#define NFS_INO_INVALID_DATA    BIT(1)          /* cached data is invalid */
 244#define NFS_INO_INVALID_ATIME   BIT(2)          /* cached atime is invalid */
 245#define NFS_INO_INVALID_ACCESS  BIT(3)          /* cached access cred invalid */
 246#define NFS_INO_INVALID_ACL     BIT(4)          /* cached acls are invalid */
 247#define NFS_INO_REVAL_PAGECACHE BIT(5)          /* must revalidate pagecache */
 248#define NFS_INO_REVAL_FORCED    BIT(6)          /* force revalidation ignoring a delegation */
 249#define NFS_INO_INVALID_LABEL   BIT(7)          /* cached label is invalid */
 250#define NFS_INO_INVALID_CHANGE  BIT(8)          /* cached change is invalid */
 251#define NFS_INO_INVALID_CTIME   BIT(9)          /* cached ctime is invalid */
 252#define NFS_INO_INVALID_MTIME   BIT(10)         /* cached mtime is invalid */
 253#define NFS_INO_INVALID_SIZE    BIT(11)         /* cached size is invalid */
 254#define NFS_INO_INVALID_OTHER   BIT(12)         /* other attrs are invalid */
 255#define NFS_INO_DATA_INVAL_DEFER        \
 256                                BIT(13)         /* Deferred cache invalidation */
 257#define NFS_INO_INVALID_BLOCKS  BIT(14)         /* cached blocks are invalid */
 258#define NFS_INO_INVALID_XATTR   BIT(15)         /* xattrs are invalid */
 259#define NFS_INO_INVALID_NLINK   BIT(16)         /* cached nlinks is invalid */
 260#define NFS_INO_INVALID_MODE    BIT(17)         /* cached mode is invalid */
 261
 262#define NFS_INO_INVALID_ATTR    (NFS_INO_INVALID_CHANGE \
 263                | NFS_INO_INVALID_CTIME \
 264                | NFS_INO_INVALID_MTIME \
 265                | NFS_INO_INVALID_SIZE \
 266                | NFS_INO_INVALID_NLINK \
 267                | NFS_INO_INVALID_MODE \
 268                | NFS_INO_INVALID_OTHER)        /* inode metadata is invalid */
 269
 270/*
 271 * Bit offsets in flags field
 272 */
 273#define NFS_INO_ADVISE_RDPLUS   (0)             /* advise readdirplus */
 274#define NFS_INO_STALE           (1)             /* possible stale inode */
 275#define NFS_INO_ACL_LRU_SET     (2)             /* Inode is on the LRU list */
 276#define NFS_INO_INVALIDATING    (3)             /* inode is being invalidated */
 277#define NFS_INO_FSCACHE         (5)             /* inode can be cached by FS-Cache */
 278#define NFS_INO_FSCACHE_LOCK    (6)             /* FS-Cache cookie management lock */
 279#define NFS_INO_FORCE_READDIR   (7)             /* force readdirplus */
 280#define NFS_INO_LAYOUTCOMMIT    (9)             /* layoutcommit required */
 281#define NFS_INO_LAYOUTCOMMITTING (10)           /* layoutcommit inflight */
 282#define NFS_INO_LAYOUTSTATS     (11)            /* layoutstats inflight */
 283#define NFS_INO_ODIRECT         (12)            /* I/O setting is O_DIRECT */
 284
 285static inline struct nfs_inode *NFS_I(const struct inode *inode)
 286{
 287        return container_of(inode, struct nfs_inode, vfs_inode);
 288}
 289
 290static inline struct nfs_server *NFS_SB(const struct super_block *s)
 291{
 292        return (struct nfs_server *)(s->s_fs_info);
 293}
 294
 295static inline struct nfs_fh *NFS_FH(const struct inode *inode)
 296{
 297        return &NFS_I(inode)->fh;
 298}
 299
 300static inline struct nfs_server *NFS_SERVER(const struct inode *inode)
 301{
 302        return NFS_SB(inode->i_sb);
 303}
 304
 305static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode)
 306{
 307        return NFS_SERVER(inode)->client;
 308}
 309
 310static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode)
 311{
 312        return NFS_SERVER(inode)->nfs_client->rpc_ops;
 313}
 314
 315static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode)
 316{
 317        struct nfs_server *nfss = NFS_SERVER(inode);
 318        return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin;
 319}
 320
 321static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode)
 322{
 323        struct nfs_server *nfss = NFS_SERVER(inode);
 324        return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax;
 325}
 326
 327static inline int NFS_STALE(const struct inode *inode)
 328{
 329        return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
 330}
 331
 332static inline struct fscache_cookie *nfs_i_fscache(struct inode *inode)
 333{
 334#ifdef CONFIG_NFS_FSCACHE
 335        return NFS_I(inode)->fscache;
 336#else
 337        return NULL;
 338#endif
 339}
 340
 341static inline __u64 NFS_FILEID(const struct inode *inode)
 342{
 343        return NFS_I(inode)->fileid;
 344}
 345
 346static inline void set_nfs_fileid(struct inode *inode, __u64 fileid)
 347{
 348        NFS_I(inode)->fileid = fileid;
 349}
 350
 351static inline void nfs_mark_for_revalidate(struct inode *inode)
 352{
 353        struct nfs_inode *nfsi = NFS_I(inode);
 354
 355        spin_lock(&inode->i_lock);
 356        nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE
 357                | NFS_INO_INVALID_ACCESS
 358                | NFS_INO_INVALID_ACL
 359                | NFS_INO_INVALID_CHANGE
 360                | NFS_INO_INVALID_CTIME;
 361        if (S_ISDIR(inode->i_mode))
 362                nfsi->cache_validity |= NFS_INO_INVALID_DATA;
 363        spin_unlock(&inode->i_lock);
 364}
 365
 366static inline int nfs_server_capable(struct inode *inode, int cap)
 367{
 368        return NFS_SERVER(inode)->caps & cap;
 369}
 370
 371/**
 372 * nfs_save_change_attribute - Returns the inode attribute change cookie
 373 * @dir - pointer to parent directory inode
 374 * The "cache change attribute" is updated when we need to revalidate
 375 * our dentry cache after a directory was seen to change on the server.
 376 */
 377static inline unsigned long nfs_save_change_attribute(struct inode *dir)
 378{
 379        return NFS_I(dir)->cache_change_attribute;
 380}
 381
 382/*
 383 * linux/fs/nfs/inode.c
 384 */
 385extern int nfs_sync_mapping(struct address_space *mapping);
 386extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping);
 387extern void nfs_zap_caches(struct inode *);
 388extern void nfs_set_inode_stale(struct inode *inode);
 389extern void nfs_invalidate_atime(struct inode *);
 390extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
 391                                struct nfs_fattr *);
 392struct inode *nfs_ilookup(struct super_block *sb, struct nfs_fattr *, struct nfs_fh *);
 393extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
 394extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
 395extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
 396extern int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr);
 397extern int nfs_getattr(struct user_namespace *, const struct path *,
 398                       struct kstat *, u32, unsigned int);
 399extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *);
 400extern void nfs_access_set_mask(struct nfs_access_entry *, u32);
 401extern int nfs_permission(struct user_namespace *, struct inode *, int);
 402extern int nfs_open(struct inode *, struct file *);
 403extern int nfs_attribute_cache_expired(struct inode *inode);
 404extern int nfs_revalidate_inode(struct inode *inode, unsigned long flags);
 405extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
 406extern int nfs_clear_invalid_mapping(struct address_space *mapping);
 407extern bool nfs_mapping_need_revalidate_inode(struct inode *inode);
 408extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
 409extern int nfs_revalidate_mapping_rcu(struct inode *inode);
 410extern int nfs_setattr(struct user_namespace *, struct dentry *, struct iattr *);
 411extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *);
 412extern void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr);
 413extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
 414extern void put_nfs_open_context(struct nfs_open_context *ctx);
 415extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode);
 416extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode, struct file *filp);
 417extern void nfs_inode_attach_open_context(struct nfs_open_context *ctx);
 418extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);
 419extern void nfs_file_clear_open_context(struct file *flip);
 420extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx);
 421extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx);
 422extern u64 nfs_compat_user_ino64(u64 fileid);
 423extern void nfs_fattr_init(struct nfs_fattr *fattr);
 424extern void nfs_fattr_set_barrier(struct nfs_fattr *fattr);
 425extern unsigned long nfs_inc_attr_generation_counter(void);
 426
 427extern struct nfs_fattr *nfs_alloc_fattr(void);
 428extern struct nfs_fattr *nfs_alloc_fattr_with_label(struct nfs_server *server);
 429
 430static inline void nfs4_label_free(struct nfs4_label *label)
 431{
 432#ifdef CONFIG_NFS_V4_SECURITY_LABEL
 433        if (label) {
 434                kfree(label->label);
 435                kfree(label);
 436        }
 437#endif
 438}
 439
 440static inline void nfs_free_fattr(const struct nfs_fattr *fattr)
 441{
 442        if (fattr)
 443                nfs4_label_free(fattr->label);
 444        kfree(fattr);
 445}
 446
 447extern struct nfs_fh *nfs_alloc_fhandle(void);
 448
 449static inline void nfs_free_fhandle(const struct nfs_fh *fh)
 450{
 451        kfree(fh);
 452}
 453
 454#ifdef NFS_DEBUG
 455extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh);
 456static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
 457{
 458        return _nfs_display_fhandle_hash(fh);
 459}
 460extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption);
 461#define nfs_display_fhandle(fh, caption)                        \
 462        do {                                                    \
 463                if (unlikely(nfs_debug & NFSDBG_FACILITY))      \
 464                        _nfs_display_fhandle(fh, caption);      \
 465        } while (0)
 466#else
 467static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
 468{
 469        return 0;
 470}
 471static inline void nfs_display_fhandle(const struct nfs_fh *fh,
 472                                       const char *caption)
 473{
 474}
 475#endif
 476
 477/*
 478 * linux/fs/nfs/nfsroot.c
 479 */
 480extern int  nfs_root_data(char **root_device, char **root_data); /*__init*/
 481/* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
 482extern __be32 root_nfs_parse_addr(char *name); /*__init*/
 483
 484/*
 485 * linux/fs/nfs/file.c
 486 */
 487extern const struct file_operations nfs_file_operations;
 488#if IS_ENABLED(CONFIG_NFS_V4)
 489extern const struct file_operations nfs4_file_operations;
 490#endif /* CONFIG_NFS_V4 */
 491extern const struct address_space_operations nfs_file_aops;
 492extern const struct address_space_operations nfs_dir_aops;
 493
 494static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
 495{
 496        return filp->private_data;
 497}
 498
 499static inline const struct cred *nfs_file_cred(struct file *file)
 500{
 501        if (file != NULL) {
 502                struct nfs_open_context *ctx =
 503                        nfs_file_open_context(file);
 504                if (ctx)
 505                        return ctx->cred;
 506        }
 507        return NULL;
 508}
 509
 510/*
 511 * linux/fs/nfs/direct.c
 512 */
 513extern ssize_t nfs_direct_IO(struct kiocb *, struct iov_iter *);
 514extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
 515                        struct iov_iter *iter);
 516extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
 517                        struct iov_iter *iter);
 518
 519/*
 520 * linux/fs/nfs/dir.c
 521 */
 522extern const struct file_operations nfs_dir_operations;
 523extern const struct dentry_operations nfs_dentry_operations;
 524
 525extern void nfs_force_lookup_revalidate(struct inode *dir);
 526extern void nfs_set_verifier(struct dentry * dentry, unsigned long verf);
 527#if IS_ENABLED(CONFIG_NFS_V4)
 528extern void nfs_clear_verifier_delegated(struct inode *inode);
 529#endif /* IS_ENABLED(CONFIG_NFS_V4) */
 530extern struct dentry *nfs_add_or_obtain(struct dentry *dentry,
 531                        struct nfs_fh *fh, struct nfs_fattr *fattr);
 532extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh,
 533                        struct nfs_fattr *fattr);
 534extern int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags);
 535extern void nfs_access_zap_cache(struct inode *inode);
 536extern int nfs_access_get_cached(struct inode *inode, const struct cred *cred, struct nfs_access_entry *res,
 537                                 bool may_block);
 538
 539/*
 540 * linux/fs/nfs/symlink.c
 541 */
 542extern const struct inode_operations nfs_symlink_inode_operations;
 543
 544/*
 545 * linux/fs/nfs/sysctl.c
 546 */
 547#ifdef CONFIG_SYSCTL
 548extern int nfs_register_sysctl(void);
 549extern void nfs_unregister_sysctl(void);
 550#else
 551#define nfs_register_sysctl() 0
 552#define nfs_unregister_sysctl() do { } while(0)
 553#endif
 554
 555/*
 556 * linux/fs/nfs/namespace.c
 557 */
 558extern const struct inode_operations nfs_mountpoint_inode_operations;
 559extern const struct inode_operations nfs_referral_inode_operations;
 560extern int nfs_mountpoint_expiry_timeout;
 561extern void nfs_release_automount_timer(void);
 562
 563/*
 564 * linux/fs/nfs/unlink.c
 565 */
 566extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);
 567
 568/*
 569 * linux/fs/nfs/write.c
 570 */
 571extern int  nfs_congestion_kb;
 572extern int  nfs_writepage(struct page *page, struct writeback_control *wbc);
 573extern int  nfs_writepages(struct address_space *, struct writeback_control *);
 574extern int  nfs_flush_incompatible(struct file *file, struct page *page);
 575extern int  nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
 576
 577/*
 578 * Try to write back everything synchronously (but check the
 579 * return value!)
 580 */
 581extern int nfs_sync_inode(struct inode *inode);
 582extern int nfs_wb_all(struct inode *inode);
 583extern int nfs_wb_page(struct inode *inode, struct page *page);
 584extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);
 585extern int  nfs_commit_inode(struct inode *, int);
 586extern struct nfs_commit_data *nfs_commitdata_alloc(bool never_fail);
 587extern void nfs_commit_free(struct nfs_commit_data *data);
 588bool nfs_commit_end(struct nfs_mds_commit_info *cinfo);
 589
 590static inline int
 591nfs_have_writebacks(struct inode *inode)
 592{
 593        if (S_ISREG(inode->i_mode))
 594                return atomic_long_read(&NFS_I(inode)->nrequests) != 0;
 595        return 0;
 596}
 597
 598/*
 599 * linux/fs/nfs/read.c
 600 */
 601extern int  nfs_readpage(struct file *, struct page *);
 602extern int  nfs_readpages(struct file *, struct address_space *,
 603                struct list_head *, unsigned);
 604
 605/*
 606 * inline functions
 607 */
 608
 609static inline loff_t nfs_size_to_loff_t(__u64 size)
 610{
 611        return min_t(u64, size, OFFSET_MAX);
 612}
 613
 614static inline ino_t
 615nfs_fileid_to_ino_t(u64 fileid)
 616{
 617        ino_t ino = (ino_t) fileid;
 618        if (sizeof(ino_t) < sizeof(u64))
 619                ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;
 620        return ino;
 621}
 622
 623#define NFS_JUKEBOX_RETRY_TIME (5 * HZ)
 624
 625
 626# undef ifdebug
 627# ifdef NFS_DEBUG
 628#  define ifdebug(fac)          if (unlikely(nfs_debug & NFSDBG_##fac))
 629#  define NFS_IFDEBUG(x)        x
 630# else
 631#  define ifdebug(fac)          if (0)
 632#  define NFS_IFDEBUG(x)
 633# endif
 634#endif
 635