linux/fs/nfs/internal.h
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   1/*
   2 * NFS internal definitions
   3 */
   4
   5#include "nfs4_fs.h"
   6#include <linux/mount.h>
   7#include <linux/security.h>
   8
   9#define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
  10
  11struct nfs_string;
  12
  13/* Maximum number of readahead requests
  14 * FIXME: this should really be a sysctl so that users may tune it to suit
  15 *        their needs. People that do NFS over a slow network, might for
  16 *        instance want to reduce it to something closer to 1 for improved
  17 *        interactive response.
  18 */
  19#define NFS_MAX_READAHEAD       (RPC_DEF_SLOT_TABLE - 1)
  20
  21/*
  22 * Determine if sessions are in use.
  23 */
  24static inline int nfs4_has_session(const struct nfs_client *clp)
  25{
  26#ifdef CONFIG_NFS_V4_1
  27        if (clp->cl_session)
  28                return 1;
  29#endif /* CONFIG_NFS_V4_1 */
  30        return 0;
  31}
  32
  33static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
  34{
  35#ifdef CONFIG_NFS_V4_1
  36        if (nfs4_has_session(clp))
  37                return (clp->cl_session->flags & SESSION4_PERSIST);
  38#endif /* CONFIG_NFS_V4_1 */
  39        return 0;
  40}
  41
  42static inline void nfs_attr_check_mountpoint(struct super_block *parent, struct nfs_fattr *fattr)
  43{
  44        if (!nfs_fsid_equal(&NFS_SB(parent)->fsid, &fattr->fsid))
  45                fattr->valid |= NFS_ATTR_FATTR_MOUNTPOINT;
  46}
  47
  48static inline int nfs_attr_use_mounted_on_fileid(struct nfs_fattr *fattr)
  49{
  50        if (((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) == 0) ||
  51            (((fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT) == 0) &&
  52             ((fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) == 0)))
  53                return 0;
  54
  55        fattr->fileid = fattr->mounted_on_fileid;
  56        return 1;
  57}
  58
  59struct nfs_clone_mount {
  60        const struct super_block *sb;
  61        const struct dentry *dentry;
  62        struct nfs_fh *fh;
  63        struct nfs_fattr *fattr;
  64        char *hostname;
  65        char *mnt_path;
  66        struct sockaddr *addr;
  67        size_t addrlen;
  68        rpc_authflavor_t authflavor;
  69};
  70
  71/*
  72 * Note: RFC 1813 doesn't limit the number of auth flavors that
  73 * a server can return, so make something up.
  74 */
  75#define NFS_MAX_SECFLAVORS      (12)
  76
  77/*
  78 * Value used if the user did not specify a port value.
  79 */
  80#define NFS_UNSPEC_PORT         (-1)
  81
  82/*
  83 * Maximum number of pages that readdir can use for creating
  84 * a vmapped array of pages.
  85 */
  86#define NFS_MAX_READDIR_PAGES 8
  87
  88struct nfs_client_initdata {
  89        unsigned long init_flags;
  90        const char *hostname;
  91        const struct sockaddr *addr;
  92        size_t addrlen;
  93        struct nfs_subversion *nfs_mod;
  94        int proto;
  95        u32 minorversion;
  96        struct net *net;
  97};
  98
  99/*
 100 * In-kernel mount arguments
 101 */
 102struct nfs_parsed_mount_data {
 103        int                     flags;
 104        int                     rsize, wsize;
 105        int                     timeo, retrans;
 106        int                     acregmin, acregmax,
 107                                acdirmin, acdirmax;
 108        int                     namlen;
 109        unsigned int            options;
 110        unsigned int            bsize;
 111        unsigned int            auth_flavor_len;
 112        rpc_authflavor_t        auth_flavors[1];
 113        char                    *client_address;
 114        unsigned int            version;
 115        unsigned int            minorversion;
 116        char                    *fscache_uniq;
 117        bool                    need_mount;
 118
 119        struct {
 120                struct sockaddr_storage address;
 121                size_t                  addrlen;
 122                char                    *hostname;
 123                u32                     version;
 124                int                     port;
 125                unsigned short          protocol;
 126        } mount_server;
 127
 128        struct {
 129                struct sockaddr_storage address;
 130                size_t                  addrlen;
 131                char                    *hostname;
 132                char                    *export_path;
 133                int                     port;
 134                unsigned short          protocol;
 135        } nfs_server;
 136
 137        struct security_mnt_opts lsm_opts;
 138        struct net              *net;
 139};
 140
 141/* mount_clnt.c */
 142struct nfs_mount_request {
 143        struct sockaddr         *sap;
 144        size_t                  salen;
 145        char                    *hostname;
 146        char                    *dirpath;
 147        u32                     version;
 148        unsigned short          protocol;
 149        struct nfs_fh           *fh;
 150        int                     noresvport;
 151        unsigned int            *auth_flav_len;
 152        rpc_authflavor_t        *auth_flavs;
 153        struct net              *net;
 154};
 155
 156struct nfs_mount_info {
 157        void (*fill_super)(struct super_block *, struct nfs_mount_info *);
 158        int (*set_security)(struct super_block *, struct dentry *, struct nfs_mount_info *);
 159        struct nfs_parsed_mount_data *parsed;
 160        struct nfs_clone_mount *cloned;
 161        struct nfs_fh *mntfh;
 162};
 163
 164extern int nfs_mount(struct nfs_mount_request *info);
 165extern void nfs_umount(const struct nfs_mount_request *info);
 166
 167/* client.c */
 168extern const struct rpc_program nfs_program;
 169extern void nfs_clients_init(struct net *net);
 170extern struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *);
 171int nfs_create_rpc_client(struct nfs_client *, const struct rpc_timeout *, rpc_authflavor_t);
 172struct nfs_client *nfs_get_client(const struct nfs_client_initdata *,
 173                                  const struct rpc_timeout *, const char *,
 174                                  rpc_authflavor_t);
 175int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *, struct nfs_fattr *);
 176void nfs_server_insert_lists(struct nfs_server *);
 177void nfs_init_timeout_values(struct rpc_timeout *, int, unsigned int, unsigned int);
 178int nfs_init_server_rpcclient(struct nfs_server *, const struct rpc_timeout *t,
 179                rpc_authflavor_t);
 180struct nfs_server *nfs_alloc_server(void);
 181void nfs_server_copy_userdata(struct nfs_server *, struct nfs_server *);
 182
 183extern void nfs_cleanup_cb_ident_idr(struct net *);
 184extern void nfs_put_client(struct nfs_client *);
 185extern void nfs_free_client(struct nfs_client *);
 186extern struct nfs_client *nfs4_find_client_ident(struct net *, int);
 187extern struct nfs_client *
 188nfs4_find_client_sessionid(struct net *, const struct sockaddr *,
 189                                struct nfs4_sessionid *);
 190extern struct nfs_server *nfs_create_server(struct nfs_mount_info *,
 191                                        struct nfs_subversion *);
 192extern struct nfs_server *nfs4_create_server(
 193                                        struct nfs_mount_info *,
 194                                        struct nfs_subversion *);
 195extern struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *,
 196                                                      struct nfs_fh *);
 197extern void nfs_free_server(struct nfs_server *server);
 198extern struct nfs_server *nfs_clone_server(struct nfs_server *,
 199                                           struct nfs_fh *,
 200                                           struct nfs_fattr *,
 201                                           rpc_authflavor_t);
 202extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
 203extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
 204extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
 205                                             const struct sockaddr *ds_addr,
 206                                             int ds_addrlen, int ds_proto,
 207                                             unsigned int ds_timeo,
 208                                             unsigned int ds_retrans);
 209#ifdef CONFIG_PROC_FS
 210extern int __init nfs_fs_proc_init(void);
 211extern void nfs_fs_proc_exit(void);
 212#else
 213static inline int nfs_fs_proc_init(void)
 214{
 215        return 0;
 216}
 217static inline void nfs_fs_proc_exit(void)
 218{
 219}
 220#endif
 221
 222#ifdef CONFIG_NFS_V4_1
 223int nfs_sockaddr_match_ipaddr(const struct sockaddr *, const struct sockaddr *);
 224#endif
 225
 226/* nfs3client.c */
 227#if IS_ENABLED(CONFIG_NFS_V3)
 228struct nfs_server *nfs3_create_server(struct nfs_mount_info *, struct nfs_subversion *);
 229struct nfs_server *nfs3_clone_server(struct nfs_server *, struct nfs_fh *,
 230                                     struct nfs_fattr *, rpc_authflavor_t);
 231#endif
 232
 233/* callback_xdr.c */
 234extern struct svc_version nfs4_callback_version1;
 235extern struct svc_version nfs4_callback_version4;
 236
 237struct nfs_pageio_descriptor;
 238/* pagelist.c */
 239extern int __init nfs_init_nfspagecache(void);
 240extern void nfs_destroy_nfspagecache(void);
 241extern int __init nfs_init_readpagecache(void);
 242extern void nfs_destroy_readpagecache(void);
 243extern int __init nfs_init_writepagecache(void);
 244extern void nfs_destroy_writepagecache(void);
 245
 246extern int __init nfs_init_directcache(void);
 247extern void nfs_destroy_directcache(void);
 248extern bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount);
 249extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
 250                              struct nfs_pgio_header *hdr,
 251                              void (*release)(struct nfs_pgio_header *hdr));
 252void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
 253
 254/* nfs2xdr.c */
 255extern struct rpc_procinfo nfs_procedures[];
 256extern int nfs2_decode_dirent(struct xdr_stream *,
 257                                struct nfs_entry *, int);
 258
 259/* nfs3xdr.c */
 260extern struct rpc_procinfo nfs3_procedures[];
 261extern int nfs3_decode_dirent(struct xdr_stream *,
 262                                struct nfs_entry *, int);
 263
 264/* nfs4xdr.c */
 265#if IS_ENABLED(CONFIG_NFS_V4)
 266extern int nfs4_decode_dirent(struct xdr_stream *,
 267                                struct nfs_entry *, int);
 268#endif
 269#ifdef CONFIG_NFS_V4_1
 270extern const u32 nfs41_maxread_overhead;
 271extern const u32 nfs41_maxwrite_overhead;
 272#endif
 273
 274/* nfs4proc.c */
 275#if IS_ENABLED(CONFIG_NFS_V4)
 276extern struct rpc_procinfo nfs4_procedures[];
 277#endif
 278
 279extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
 280
 281/* proc.c */
 282void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
 283extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
 284                           const struct rpc_timeout *timeparms,
 285                           const char *ip_addr, rpc_authflavor_t authflavour);
 286
 287/* dir.c */
 288extern int nfs_access_cache_shrinker(struct shrinker *shrink,
 289                                        struct shrink_control *sc);
 290struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
 291int nfs_create(struct inode *, struct dentry *, umode_t, bool);
 292int nfs_mkdir(struct inode *, struct dentry *, umode_t);
 293int nfs_rmdir(struct inode *, struct dentry *);
 294int nfs_unlink(struct inode *, struct dentry *);
 295int nfs_symlink(struct inode *, struct dentry *, const char *);
 296int nfs_link(struct dentry *, struct inode *, struct dentry *);
 297int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
 298int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
 299
 300/* file.c */
 301int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
 302loff_t nfs_file_llseek(struct file *, loff_t, int);
 303int nfs_file_flush(struct file *, fl_owner_t);
 304ssize_t nfs_file_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
 305ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
 306                             size_t, unsigned int);
 307int nfs_file_mmap(struct file *, struct vm_area_struct *);
 308ssize_t nfs_file_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
 309int nfs_file_release(struct inode *, struct file *);
 310int nfs_lock(struct file *, int, struct file_lock *);
 311int nfs_flock(struct file *, int, struct file_lock *);
 312ssize_t nfs_file_splice_write(struct pipe_inode_info *, struct file *, loff_t *,
 313                              size_t, unsigned int);
 314int nfs_check_flags(int);
 315int nfs_setlease(struct file *, long, struct file_lock **);
 316
 317/* inode.c */
 318extern struct workqueue_struct *nfsiod_workqueue;
 319extern struct inode *nfs_alloc_inode(struct super_block *sb);
 320extern void nfs_destroy_inode(struct inode *);
 321extern int nfs_write_inode(struct inode *, struct writeback_control *);
 322extern void nfs_clear_inode(struct inode *);
 323extern void nfs_evict_inode(struct inode *);
 324void nfs_zap_acl_cache(struct inode *inode);
 325extern int nfs_wait_bit_killable(void *word);
 326
 327/* super.c */
 328extern const struct super_operations nfs_sops;
 329extern struct file_system_type nfs_fs_type;
 330extern struct file_system_type nfs_xdev_fs_type;
 331#if IS_ENABLED(CONFIG_NFS_V4)
 332extern struct file_system_type nfs4_xdev_fs_type;
 333extern struct file_system_type nfs4_referral_fs_type;
 334#endif
 335struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
 336                        struct nfs_subversion *);
 337void nfs_initialise_sb(struct super_block *);
 338int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 339int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 340struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
 341                                   struct nfs_mount_info *, struct nfs_subversion *);
 342struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
 343struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
 344                const char *, struct nfs_mount_info *);
 345void nfs_kill_super(struct super_block *);
 346void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
 347
 348extern struct rpc_stat nfs_rpcstat;
 349
 350extern int __init register_nfs_fs(void);
 351extern void __exit unregister_nfs_fs(void);
 352extern void nfs_sb_active(struct super_block *sb);
 353extern void nfs_sb_deactive(struct super_block *sb);
 354
 355/* namespace.c */
 356extern char *nfs_path(char **p, struct dentry *dentry,
 357                      char *buffer, ssize_t buflen);
 358extern struct vfsmount *nfs_d_automount(struct path *path);
 359struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
 360                              struct nfs_fh *, struct nfs_fattr *);
 361struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
 362                                 struct nfs_fattr *, rpc_authflavor_t);
 363
 364/* getroot.c */
 365extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
 366                                   const char *);
 367#if IS_ENABLED(CONFIG_NFS_V4)
 368extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
 369                                    const char *);
 370
 371extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh);
 372#endif
 373
 374struct nfs_pgio_completion_ops;
 375/* read.c */
 376extern struct nfs_read_header *nfs_readhdr_alloc(void);
 377extern void nfs_readhdr_free(struct nfs_pgio_header *hdr);
 378extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
 379                        struct inode *inode,
 380                        const struct nfs_pgio_completion_ops *compl_ops);
 381extern int nfs_initiate_read(struct rpc_clnt *clnt,
 382                             struct nfs_read_data *data,
 383                             const struct rpc_call_ops *call_ops, int flags);
 384extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
 385extern int nfs_generic_pagein(struct nfs_pageio_descriptor *desc,
 386                              struct nfs_pgio_header *hdr);
 387extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
 388                        struct inode *inode,
 389                        const struct nfs_pgio_completion_ops *compl_ops);
 390extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
 391extern void nfs_readdata_release(struct nfs_read_data *rdata);
 392
 393/* super.c */
 394void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
 395void nfs_umount_begin(struct super_block *);
 396int  nfs_statfs(struct dentry *, struct kstatfs *);
 397int  nfs_show_options(struct seq_file *, struct dentry *);
 398int  nfs_show_devname(struct seq_file *, struct dentry *);
 399int  nfs_show_path(struct seq_file *, struct dentry *);
 400int  nfs_show_stats(struct seq_file *, struct dentry *);
 401void nfs_put_super(struct super_block *);
 402int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 403
 404/* write.c */
 405extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
 406                        struct inode *inode, int ioflags,
 407                        const struct nfs_pgio_completion_ops *compl_ops);
 408extern struct nfs_write_header *nfs_writehdr_alloc(void);
 409extern void nfs_writehdr_free(struct nfs_pgio_header *hdr);
 410extern int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
 411                             struct nfs_pgio_header *hdr);
 412extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
 413                        struct inode *inode, int ioflags,
 414                        const struct nfs_pgio_completion_ops *compl_ops);
 415extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
 416extern void nfs_writedata_release(struct nfs_write_data *wdata);
 417extern void nfs_commit_free(struct nfs_commit_data *p);
 418extern int nfs_initiate_write(struct rpc_clnt *clnt,
 419                              struct nfs_write_data *data,
 420                              const struct rpc_call_ops *call_ops,
 421                              int how, int flags);
 422extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
 423extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
 424extern int nfs_initiate_commit(struct rpc_clnt *clnt,
 425                               struct nfs_commit_data *data,
 426                               const struct rpc_call_ops *call_ops,
 427                               int how, int flags);
 428extern void nfs_init_commit(struct nfs_commit_data *data,
 429                            struct list_head *head,
 430                            struct pnfs_layout_segment *lseg,
 431                            struct nfs_commit_info *cinfo);
 432int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
 433                         struct nfs_commit_info *cinfo, int max);
 434int nfs_scan_commit(struct inode *inode, struct list_head *dst,
 435                    struct nfs_commit_info *cinfo);
 436void nfs_mark_request_commit(struct nfs_page *req,
 437                             struct pnfs_layout_segment *lseg,
 438                             struct nfs_commit_info *cinfo);
 439int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
 440                            int how, struct nfs_commit_info *cinfo);
 441void nfs_retry_commit(struct list_head *page_list,
 442                      struct pnfs_layout_segment *lseg,
 443                      struct nfs_commit_info *cinfo);
 444void nfs_commitdata_release(struct nfs_commit_data *data);
 445void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
 446                                 struct nfs_commit_info *cinfo);
 447void nfs_request_remove_commit_list(struct nfs_page *req,
 448                                    struct nfs_commit_info *cinfo);
 449void nfs_init_cinfo(struct nfs_commit_info *cinfo,
 450                    struct inode *inode,
 451                    struct nfs_direct_req *dreq);
 452
 453#ifdef CONFIG_MIGRATION
 454extern int nfs_migrate_page(struct address_space *,
 455                struct page *, struct page *, enum migrate_mode);
 456#else
 457#define nfs_migrate_page NULL
 458#endif
 459
 460/* direct.c */
 461void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
 462                              struct nfs_direct_req *dreq);
 463static inline void nfs_inode_dio_wait(struct inode *inode)
 464{
 465        inode_dio_wait(inode);
 466}
 467
 468/* nfs4proc.c */
 469extern void __nfs4_read_done_cb(struct nfs_read_data *);
 470extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
 471                            const struct rpc_timeout *timeparms,
 472                            const char *ip_addr,
 473                            rpc_authflavor_t authflavour);
 474extern int _nfs4_call_sync(struct rpc_clnt *clnt,
 475                           struct nfs_server *server,
 476                           struct rpc_message *msg,
 477                           struct nfs4_sequence_args *args,
 478                           struct nfs4_sequence_res *res,
 479                           int cache_reply);
 480extern int _nfs4_call_sync_session(struct rpc_clnt *clnt,
 481                                   struct nfs_server *server,
 482                                   struct rpc_message *msg,
 483                                   struct nfs4_sequence_args *args,
 484                                   struct nfs4_sequence_res *res,
 485                                   int cache_reply);
 486
 487/*
 488 * Determine the device name as a string
 489 */
 490static inline char *nfs_devname(struct dentry *dentry,
 491                                char *buffer, ssize_t buflen)
 492{
 493        char *dummy;
 494        return nfs_path(&dummy, dentry, buffer, buflen);
 495}
 496
 497/*
 498 * Determine the actual block size (and log2 thereof)
 499 */
 500static inline
 501unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
 502{
 503        /* make sure blocksize is a power of two */
 504        if ((bsize & (bsize - 1)) || nrbitsp) {
 505                unsigned char   nrbits;
 506
 507                for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
 508                        ;
 509                bsize = 1 << nrbits;
 510                if (nrbitsp)
 511                        *nrbitsp = nrbits;
 512        }
 513
 514        return bsize;
 515}
 516
 517/*
 518 * Calculate the number of 512byte blocks used.
 519 */
 520static inline blkcnt_t nfs_calc_block_size(u64 tsize)
 521{
 522        blkcnt_t used = (tsize + 511) >> 9;
 523        return (used > ULONG_MAX) ? ULONG_MAX : used;
 524}
 525
 526/*
 527 * Compute and set NFS server blocksize
 528 */
 529static inline
 530unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
 531{
 532        if (bsize < NFS_MIN_FILE_IO_SIZE)
 533                bsize = NFS_DEF_FILE_IO_SIZE;
 534        else if (bsize >= NFS_MAX_FILE_IO_SIZE)
 535                bsize = NFS_MAX_FILE_IO_SIZE;
 536
 537        return nfs_block_bits(bsize, nrbitsp);
 538}
 539
 540/*
 541 * Determine the maximum file size for a superblock
 542 */
 543static inline
 544void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
 545{
 546        sb->s_maxbytes = (loff_t)maxfilesize;
 547        if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
 548                sb->s_maxbytes = MAX_LFS_FILESIZE;
 549}
 550
 551/*
 552 * Determine the number of bytes of data the page contains
 553 */
 554static inline
 555unsigned int nfs_page_length(struct page *page)
 556{
 557        loff_t i_size = i_size_read(page_file_mapping(page)->host);
 558
 559        if (i_size > 0) {
 560                pgoff_t page_index = page_file_index(page);
 561                pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
 562                if (page_index < end_index)
 563                        return PAGE_CACHE_SIZE;
 564                if (page_index == end_index)
 565                        return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
 566        }
 567        return 0;
 568}
 569
 570/*
 571 * Convert a umode to a dirent->d_type
 572 */
 573static inline
 574unsigned char nfs_umode_to_dtype(umode_t mode)
 575{
 576        return (mode >> 12) & 15;
 577}
 578
 579/*
 580 * Determine the number of pages in an array of length 'len' and
 581 * with a base offset of 'base'
 582 */
 583static inline
 584unsigned int nfs_page_array_len(unsigned int base, size_t len)
 585{
 586        return ((unsigned long)len + (unsigned long)base +
 587                PAGE_SIZE - 1) >> PAGE_SHIFT;
 588}
 589
 590/*
 591 * Convert a struct timespec into a 64-bit change attribute
 592 *
 593 * This does approximately the same thing as timespec_to_ns(),
 594 * but for calculation efficiency, we multiply the seconds by
 595 * 1024*1024*1024.
 596 */
 597static inline
 598u64 nfs_timespec_to_change_attr(const struct timespec *ts)
 599{
 600        return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
 601}
 602