fs/nfs/internal.h

   1 /*
   2  * NFS internal definitions
   3  */
   4
   5 #include "nfs4_fs.h"
   6 #include <linux/mount.h>
   7 #include <linux/security.h>
   8 #include <linux/crc32.h>
   9
  10 #define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
  11
  12 struct nfs_string;
  13
  14 /* Maximum number of readahead requests
  15  * FIXME: this should really be a sysctl so that users may tune it to suit
  16  *        their needs. People that do NFS over a slow network, might for
  17  *        instance want to reduce it to something closer to 1 for improved
  18  *        interactive response.
  19  */
  20 #define NFS_MAX_READAHEAD       (RPC_DEF_SLOT_TABLE - 1)
  21
  22 static inline void nfs_attr_check_mountpoint(struct super_block *parent, struct nfs_fattr *fattr)
  23 {
  24         if (!nfs_fsid_equal(&NFS_SB(parent)->fsid, &fattr->fsid))
  25                 fattr->valid |= NFS_ATTR_FATTR_MOUNTPOINT;
  26 }
  27
  28 static inline int nfs_attr_use_mounted_on_fileid(struct nfs_fattr *fattr)
  29 {
  30         if (((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) == 0) ||
  31             (((fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT) == 0) &&
  32              ((fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) == 0)))
  33                 return 0;
  34
  35         fattr->fileid = fattr->mounted_on_fileid;
  36         return 1;
  37 }
  38
  39 struct nfs_clone_mount {
  40         const struct super_block *sb;
  41         const struct dentry *dentry;
  42         struct nfs_fh *fh;
  43         struct nfs_fattr *fattr;
  44         char *hostname;
  45         char *mnt_path;
  46         struct sockaddr *addr;
  47         size_t addrlen;
  48         rpc_authflavor_t authflavor;
  49 };
  50
  51 /*
  52  * Note: RFC 1813 doesn't limit the number of auth flavors that
  53  * a server can return, so make something up.
  54  */
  55 #define NFS_MAX_SECFLAVORS      (12)
  56
  57 /*
  58  * Value used if the user did not specify a port value.
  59  */
  60 #define NFS_UNSPEC_PORT         (-1)
  61
  62 /*
  63  * Maximum number of pages that readdir can use for creating
  64  * a vmapped array of pages.
  65  */
  66 #define NFS_MAX_READDIR_PAGES 8
  67
  68 struct nfs_client_initdata {
  69         unsigned long init_flags;
  70         const char *hostname;
  71         const struct sockaddr *addr;
  72         size_t addrlen;
  73         struct nfs_subversion *nfs_mod;
  74         int proto;
  75         u32 minorversion;
  76         struct net *net;
  77 };
  78
  79 /*
  80  * In-kernel mount arguments
  81  */
  82 struct nfs_parsed_mount_data {
  83         int                     flags;
  84         unsigned int            rsize, wsize;
  85         unsigned int            timeo, retrans;
  86         unsigned int            acregmin, acregmax,
  87                                 acdirmin, acdirmax;
  88         unsigned int            namlen;
  89         unsigned int            options;
  90         unsigned int            bsize;
  91         struct nfs_auth_info    auth_info;
  92         rpc_authflavor_t        selected_flavor;
  93         char                    *client_address;
  94         unsigned int            version;
  95         unsigned int            minorversion;
  96         char                    *fscache_uniq;
  97         bool                    need_mount;
  98
  99         struct {
 100                 struct sockaddr_storage address;
 101                 size_t                  addrlen;
 102                 char                    *hostname;
 103                 u32                     version;
 104                 int                     port;
 105                 unsigned short          protocol;
 106         } mount_server;
 107
 108         struct {
 109                 struct sockaddr_storage address;
 110                 size_t                  addrlen;
 111                 char                    *hostname;
 112                 char                    *export_path;
 113                 int                     port;
 114                 unsigned short          protocol;
 115         } nfs_server;
 116
 117         struct security_mnt_opts lsm_opts;
 118         struct net              *net;
 119 };
 120
 121 /* mount_clnt.c */
 122 struct nfs_mount_request {
 123         struct sockaddr         *sap;
 124         size_t                  salen;
 125         char                    *hostname;
 126         char                    *dirpath;
 127         u32                     version;
 128         unsigned short          protocol;
 129         struct nfs_fh           *fh;
 130         int                     noresvport;
 131         unsigned int            *auth_flav_len;
 132         rpc_authflavor_t        *auth_flavs;
 133         struct net              *net;
 134 };
 135
 136 struct nfs_mount_info {
 137         void (*fill_super)(struct super_block *, struct nfs_mount_info *);
 138         int (*set_security)(struct super_block *, struct dentry *, struct nfs_mount_info *);
 139         struct nfs_parsed_mount_data *parsed;
 140         struct nfs_clone_mount *cloned;
 141         struct nfs_fh *mntfh;
 142 };
 143
 144 extern int nfs_mount(struct nfs_mount_request *info);
 145 extern void nfs_umount(const struct nfs_mount_request *info);
 146
 147 /* client.c */
 148 extern const struct rpc_program nfs_program;
 149 extern void nfs_clients_init(struct net *net);
 150 extern struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *);
 151 int nfs_create_rpc_client(struct nfs_client *, const struct rpc_timeout *, rpc_authflavor_t);
 152 struct nfs_client *nfs_get_client(const struct nfs_client_initdata *,
 153                                   const struct rpc_timeout *, const char *,
 154                                   rpc_authflavor_t);
 155 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *, struct nfs_fattr *);
 156 void nfs_server_insert_lists(struct nfs_server *);
 157 void nfs_server_remove_lists(struct nfs_server *);
 158 void nfs_init_timeout_values(struct rpc_timeout *, int, unsigned int, unsigned int);
 159 int nfs_init_server_rpcclient(struct nfs_server *, const struct rpc_timeout *t,
 160                 rpc_authflavor_t);
 161 struct nfs_server *nfs_alloc_server(void);
 162 void nfs_server_copy_userdata(struct nfs_server *, struct nfs_server *);
 163
 164 extern void nfs_cleanup_cb_ident_idr(struct net *);
 165 extern void nfs_put_client(struct nfs_client *);
 166 extern void nfs_free_client(struct nfs_client *);
 167 extern struct nfs_client *nfs4_find_client_ident(struct net *, int);
 168 extern struct nfs_client *
 169 nfs4_find_client_sessionid(struct net *, const struct sockaddr *,
 170                                 struct nfs4_sessionid *, u32);
 171 extern struct nfs_server *nfs_create_server(struct nfs_mount_info *,
 172                                         struct nfs_subversion *);
 173 extern struct nfs_server *nfs4_create_server(
 174                                         struct nfs_mount_info *,
 175                                         struct nfs_subversion *);
 176 extern struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *,
 177                                                       struct nfs_fh *);
 178 extern int nfs4_update_server(struct nfs_server *server, const char *hostname,
 179                                         struct sockaddr *sap, size_t salen);
 180 extern void nfs_free_server(struct nfs_server *server);
 181 extern struct nfs_server *nfs_clone_server(struct nfs_server *,
 182                                            struct nfs_fh *,
 183                                            struct nfs_fattr *,
 184                                            rpc_authflavor_t);
 185 extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
 186 extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
 187 extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
 188                                              const struct sockaddr *ds_addr,
 189                                              int ds_addrlen, int ds_proto,
 190                                              unsigned int ds_timeo,
 191                                              unsigned int ds_retrans);
 192 extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
 193                                                 struct inode *);
 194 #ifdef CONFIG_PROC_FS
 195 extern int __init nfs_fs_proc_init(void);
 196 extern void nfs_fs_proc_exit(void);
 197 #else
 198 static inline int nfs_fs_proc_init(void)
 199 {
 200         return 0;
 201 }
 202 static inline void nfs_fs_proc_exit(void)
 203 {
 204 }
 205 #endif
 206
 207 #ifdef CONFIG_NFS_V4_1
 208 int nfs_sockaddr_match_ipaddr(const struct sockaddr *, const struct sockaddr *);
 209 #endif
 210
 211 /* nfs3client.c */
 212 #if IS_ENABLED(CONFIG_NFS_V3)
 213 struct nfs_server *nfs3_create_server(struct nfs_mount_info *, struct nfs_subversion *);
 214 struct nfs_server *nfs3_clone_server(struct nfs_server *, struct nfs_fh *,
 215                                      struct nfs_fattr *, rpc_authflavor_t);
 216 #endif
 217
 218 /* callback_xdr.c */
 219 extern struct svc_version nfs4_callback_version1;
 220 extern struct svc_version nfs4_callback_version4;
 221
 222 struct nfs_pageio_descriptor;
 223 /* pagelist.c */
 224 extern int __init nfs_init_nfspagecache(void);
 225 extern void nfs_destroy_nfspagecache(void);
 226 extern int __init nfs_init_readpagecache(void);
 227 extern void nfs_destroy_readpagecache(void);
 228 extern int __init nfs_init_writepagecache(void);
 229 extern void nfs_destroy_writepagecache(void);
 230
 231 extern int __init nfs_init_directcache(void);
 232 extern void nfs_destroy_directcache(void);
 233 extern bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount);
 234 extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
 235                               struct nfs_pgio_header *hdr,
 236                               void (*release)(struct nfs_pgio_header *hdr));
 237 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
 238 int nfs_iocounter_wait(struct nfs_io_counter *c);
 239
 240 static inline void nfs_iocounter_init(struct nfs_io_counter *c)
 241 {
 242         c->flags = 0;
 243         atomic_set(&c->io_count, 0);
 244 }
 245
 246 /* nfs2xdr.c */
 247 extern struct rpc_procinfo nfs_procedures[];
 248 extern int nfs2_decode_dirent(struct xdr_stream *,
 249                                 struct nfs_entry *, int);
 250
 251 /* nfs3xdr.c */
 252 extern struct rpc_procinfo nfs3_procedures[];
 253 extern int nfs3_decode_dirent(struct xdr_stream *,
 254                                 struct nfs_entry *, int);
 255
 256 /* nfs4xdr.c */
 257 #if IS_ENABLED(CONFIG_NFS_V4)
 258 extern int nfs4_decode_dirent(struct xdr_stream *,
 259                                 struct nfs_entry *, int);
 260 #endif
 261 #ifdef CONFIG_NFS_V4_1
 262 extern const u32 nfs41_maxread_overhead;
 263 extern const u32 nfs41_maxwrite_overhead;
 264 extern const u32 nfs41_maxgetdevinfo_overhead;
 265 #endif
 266
 267 /* nfs4proc.c */
 268 #if IS_ENABLED(CONFIG_NFS_V4)
 269 extern struct rpc_procinfo nfs4_procedures[];
 270 #endif
 271
 272 /* proc.c */
 273 void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
 274 extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
 275                            const struct rpc_timeout *timeparms,
 276                            const char *ip_addr);
 277
 278 /* dir.c */
 279 extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
 280                                             struct shrink_control *sc);
 281 extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
 282                                            struct shrink_control *sc);
 283 struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
 284 int nfs_create(struct inode *, struct dentry *, umode_t, bool);
 285 int nfs_mkdir(struct inode *, struct dentry *, umode_t);
 286 int nfs_rmdir(struct inode *, struct dentry *);
 287 int nfs_unlink(struct inode *, struct dentry *);
 288 int nfs_symlink(struct inode *, struct dentry *, const char *);
 289 int nfs_link(struct dentry *, struct inode *, struct dentry *);
 290 int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
 291 int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
 292
 293 /* file.c */
 294 int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
 295 loff_t nfs_file_llseek(struct file *, loff_t, int);
 296 int nfs_file_flush(struct file *, fl_owner_t);
 297 ssize_t nfs_file_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
 298 ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
 299                              size_t, unsigned int);
 300 int nfs_file_mmap(struct file *, struct vm_area_struct *);
 301 ssize_t nfs_file_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
 302 int nfs_file_release(struct inode *, struct file *);
 303 int nfs_lock(struct file *, int, struct file_lock *);
 304 int nfs_flock(struct file *, int, struct file_lock *);
 305 ssize_t nfs_file_splice_write(struct pipe_inode_info *, struct file *, loff_t *,
 306                               size_t, unsigned int);
 307 int nfs_check_flags(int);
 308 int nfs_setlease(struct file *, long, struct file_lock **);
 309
 310 /* inode.c */
 311 extern struct workqueue_struct *nfsiod_workqueue;
 312 extern struct inode *nfs_alloc_inode(struct super_block *sb);
 313 extern void nfs_destroy_inode(struct inode *);
 314 extern int nfs_write_inode(struct inode *, struct writeback_control *);
 315 extern int nfs_drop_inode(struct inode *);
 316 extern void nfs_clear_inode(struct inode *);
 317 extern void nfs_evict_inode(struct inode *);
 318 void nfs_zap_acl_cache(struct inode *inode);
 319 extern int nfs_wait_bit_killable(void *word);
 320
 321 /* super.c */
 322 extern const struct super_operations nfs_sops;
 323 extern struct file_system_type nfs_fs_type;
 324 extern struct file_system_type nfs_xdev_fs_type;
 325 #if IS_ENABLED(CONFIG_NFS_V4)
 326 extern struct file_system_type nfs4_xdev_fs_type;
 327 extern struct file_system_type nfs4_referral_fs_type;
 328 #endif
 329 bool nfs_auth_info_match(const struct nfs_auth_info *, rpc_authflavor_t);
 330 struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
 331                         struct nfs_subversion *);
 332 void nfs_initialise_sb(struct super_block *);
 333 int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 334 int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 335 struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
 336                                    struct nfs_mount_info *, struct nfs_subversion *);
 337 struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
 338 struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
 339                 const char *, struct nfs_mount_info *);
 340 void nfs_kill_super(struct super_block *);
 341 void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
 342
 343 extern struct rpc_stat nfs_rpcstat;
 344
 345 extern int __init register_nfs_fs(void);
 346 extern void __exit unregister_nfs_fs(void);
 347 extern void nfs_sb_active(struct super_block *sb);
 348 extern void nfs_sb_deactive(struct super_block *sb);
 349
 350 /* namespace.c */
 351 #define NFS_PATH_CANONICAL 1
 352 extern char *nfs_path(char **p, struct dentry *dentry,
 353                       char *buffer, ssize_t buflen, unsigned flags);
 354 extern struct vfsmount *nfs_d_automount(struct path *path);
 355 struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
 356                               struct nfs_fh *, struct nfs_fattr *);
 357 struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
 358                                  struct nfs_fattr *, rpc_authflavor_t);
 359
 360 /* getroot.c */
 361 extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
 362                                    const char *);
 363 #if IS_ENABLED(CONFIG_NFS_V4)
 364 extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
 365                                     const char *);
 366
 367 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool);
 368 #endif
 369
 370 struct nfs_pgio_completion_ops;
 371 /* read.c */
 372 extern struct nfs_read_header *nfs_readhdr_alloc(void);
 373 extern void nfs_readhdr_free(struct nfs_pgio_header *hdr);
 374 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
 375                         struct inode *inode,
 376                         const struct nfs_pgio_completion_ops *compl_ops);
 377 extern int nfs_initiate_read(struct rpc_clnt *clnt,
 378                              struct nfs_read_data *data,
 379                              const struct rpc_call_ops *call_ops, int flags);
 380 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
 381 extern int nfs_generic_pagein(struct nfs_pageio_descriptor *desc,
 382                               struct nfs_pgio_header *hdr);
 383 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
 384 extern void nfs_readdata_release(struct nfs_read_data *rdata);
 385
 386 /* super.c */
 387 void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
 388 void nfs_umount_begin(struct super_block *);
 389 int  nfs_statfs(struct dentry *, struct kstatfs *);
 390 int  nfs_show_options(struct seq_file *, struct dentry *);
 391 int  nfs_show_devname(struct seq_file *, struct dentry *);
 392 int  nfs_show_path(struct seq_file *, struct dentry *);
 393 int  nfs_show_stats(struct seq_file *, struct dentry *);
 394 void nfs_put_super(struct super_block *);
 395 int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 396
 397 /* write.c */
 398 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
 399                         struct inode *inode, int ioflags,
 400                         const struct nfs_pgio_completion_ops *compl_ops);
 401 extern struct nfs_write_header *nfs_writehdr_alloc(void);
 402 extern void nfs_writehdr_free(struct nfs_pgio_header *hdr);
 403 extern int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
 404                              struct nfs_pgio_header *hdr);
 405 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
 406 extern void nfs_writedata_release(struct nfs_write_data *wdata);
 407 extern void nfs_commit_free(struct nfs_commit_data *p);
 408 extern int nfs_initiate_write(struct rpc_clnt *clnt,
 409                               struct nfs_write_data *data,
 410                               const struct rpc_call_ops *call_ops,
 411                               int how, int flags);
 412 extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
 413 extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
 414 extern int nfs_initiate_commit(struct rpc_clnt *clnt,
 415                                struct nfs_commit_data *data,
 416                                const struct rpc_call_ops *call_ops,
 417                                int how, int flags);
 418 extern void nfs_init_commit(struct nfs_commit_data *data,
 419                             struct list_head *head,
 420                             struct pnfs_layout_segment *lseg,
 421                             struct nfs_commit_info *cinfo);
 422 int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
 423                          struct nfs_commit_info *cinfo, int max);
 424 int nfs_scan_commit(struct inode *inode, struct list_head *dst,
 425                     struct nfs_commit_info *cinfo);
 426 void nfs_mark_request_commit(struct nfs_page *req,
 427                              struct pnfs_layout_segment *lseg,
 428                              struct nfs_commit_info *cinfo);
 429 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
 430                             int how, struct nfs_commit_info *cinfo);
 431 void nfs_retry_commit(struct list_head *page_list,
 432                       struct pnfs_layout_segment *lseg,
 433                       struct nfs_commit_info *cinfo);
 434 void nfs_commitdata_release(struct nfs_commit_data *data);
 435 void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
 436                                  struct nfs_commit_info *cinfo);
 437 void nfs_request_remove_commit_list(struct nfs_page *req,
 438                                     struct nfs_commit_info *cinfo);
 439 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
 440                     struct inode *inode,
 441                     struct nfs_direct_req *dreq);
 442 int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
 443 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
 444
 445 #ifdef CONFIG_MIGRATION
 446 extern int nfs_migrate_page(struct address_space *,
 447                 struct page *, struct page *, enum migrate_mode);
 448 #else
 449 #define nfs_migrate_page NULL
 450 #endif
 451
 452 /* direct.c */
 453 void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
 454                               struct nfs_direct_req *dreq);
 455 static inline void nfs_inode_dio_wait(struct inode *inode)
 456 {
 457         inode_dio_wait(inode);
 458 }
 459 extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
 460
 461 /* nfs4proc.c */
 462 extern void __nfs4_read_done_cb(struct nfs_read_data *);
 463 extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
 464                             const struct rpc_timeout *timeparms,
 465                             const char *ip_addr);
 466 extern int nfs40_walk_client_list(struct nfs_client *clp,
 467                                 struct nfs_client **result,
 468                                 struct rpc_cred *cred);
 469 extern int nfs41_walk_client_list(struct nfs_client *clp,
 470                                 struct nfs_client **result,
 471                                 struct rpc_cred *cred);
 472
 473 /*
 474  * Determine the device name as a string
 475  */
 476 static inline char *nfs_devname(struct dentry *dentry,
 477                                 char *buffer, ssize_t buflen)
 478 {
 479         char *dummy;
 480         return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
 481 }
 482
 483 /*
 484  * Determine the actual block size (and log2 thereof)
 485  */
 486 static inline
 487 unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
 488 {
 489         /* make sure blocksize is a power of two */
 490         if ((bsize & (bsize - 1)) || nrbitsp) {
 491                 unsigned char   nrbits;
 492
 493                 for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
 494                         ;
 495                 bsize = 1 << nrbits;
 496                 if (nrbitsp)
 497                         *nrbitsp = nrbits;
 498         }
 499
 500         return bsize;
 501 }
 502
 503 /*
 504  * Calculate the number of 512byte blocks used.
 505  */
 506 static inline blkcnt_t nfs_calc_block_size(u64 tsize)
 507 {
 508         blkcnt_t used = (tsize + 511) >> 9;
 509         return (used > ULONG_MAX) ? ULONG_MAX : used;
 510 }
 511
 512 /*
 513  * Compute and set NFS server blocksize
 514  */
 515 static inline
 516 unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
 517 {
 518         if (bsize < NFS_MIN_FILE_IO_SIZE)
 519                 bsize = NFS_DEF_FILE_IO_SIZE;
 520         else if (bsize >= NFS_MAX_FILE_IO_SIZE)
 521                 bsize = NFS_MAX_FILE_IO_SIZE;
 522
 523         return nfs_block_bits(bsize, nrbitsp);
 524 }
 525
 526 /*
 527  * Determine the maximum file size for a superblock
 528  */
 529 static inline
 530 void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
 531 {
 532         sb->s_maxbytes = (loff_t)maxfilesize;
 533         if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
 534                 sb->s_maxbytes = MAX_LFS_FILESIZE;
 535 }
 536
 537 /*
 538  * Determine the number of bytes of data the page contains
 539  */
 540 static inline
 541 unsigned int nfs_page_length(struct page *page)
 542 {
 543         loff_t i_size = i_size_read(page_file_mapping(page)->host);
 544
 545         if (i_size > 0) {
 546                 pgoff_t page_index = page_file_index(page);
 547                 pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
 548                 if (page_index < end_index)
 549                         return PAGE_CACHE_SIZE;
 550                 if (page_index == end_index)
 551                         return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
 552         }
 553         return 0;
 554 }
 555
 556 /*
 557  * Convert a umode to a dirent->d_type
 558  */
 559 static inline
 560 unsigned char nfs_umode_to_dtype(umode_t mode)
 561 {
 562         return (mode >> 12) & 15;
 563 }
 564
 565 /*
 566  * Determine the number of pages in an array of length 'len' and
 567  * with a base offset of 'base'
 568  */
 569 static inline
 570 unsigned int nfs_page_array_len(unsigned int base, size_t len)
 571 {
 572         return ((unsigned long)len + (unsigned long)base +
 573                 PAGE_SIZE - 1) >> PAGE_SHIFT;
 574 }
 575
 576 /*
 577  * Convert a struct timespec into a 64-bit change attribute
 578  *
 579  * This does approximately the same thing as timespec_to_ns(),
 580  * but for calculation efficiency, we multiply the seconds by
 581  * 1024*1024*1024.
 582  */
 583 static inline
 584 u64 nfs_timespec_to_change_attr(const struct timespec *ts)
 585 {
 586         return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
 587 }
 588
 589 #ifdef CONFIG_CRC32
 590 /**
 591  * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
 592  * @fh - pointer to filehandle
 593  *
 594  * returns a crc32 hash for the filehandle that is compatible with
 595  * the one displayed by "wireshark".
 596  */
 597 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
 598 {
 599         return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
 600 }
 601 #else
 602 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
 603 {
 604         return 0;
 605 }
 606 #endif