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
   9 #define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
  10
  11 struct 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  */
  24 static 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
  33 static 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
  42 static 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
  48 static 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
  59 struct 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
  88 struct 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  */
 102 struct 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 */
 142 struct 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
 156 struct 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
 164 extern int nfs_mount(struct nfs_mount_request *info);
 165 extern void nfs_umount(const struct nfs_mount_request *info);
 166
 167 /* client.c */
 168 extern const struct rpc_program nfs_program;
 169 extern void nfs_clients_init(struct net *net);
 170 extern struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *);
 171 int nfs_create_rpc_client(struct nfs_client *, const struct rpc_timeout *, rpc_authflavor_t);
 172 struct nfs_client *nfs_get_client(const struct nfs_client_initdata *,
 173                                   const struct rpc_timeout *, const char *,
 174                                   rpc_authflavor_t);
 175 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *, struct nfs_fattr *);
 176 void nfs_server_insert_lists(struct nfs_server *);
 177 void nfs_init_timeout_values(struct rpc_timeout *, int, unsigned int, unsigned int);
 178 int nfs_init_server_rpcclient(struct nfs_server *, const struct rpc_timeout *t,
 179                 rpc_authflavor_t);
 180 struct nfs_server *nfs_alloc_server(void);
 181 void nfs_server_copy_userdata(struct nfs_server *, struct nfs_server *);
 182
 183 extern void nfs_cleanup_cb_ident_idr(struct net *);
 184 extern void nfs_put_client(struct nfs_client *);
 185 extern void nfs_free_client(struct nfs_client *);
 186 extern struct nfs_client *nfs4_find_client_ident(struct net *, int);
 187 extern struct nfs_client *
 188 nfs4_find_client_sessionid(struct net *, const struct sockaddr *,
 189                                 struct nfs4_sessionid *);
 190 extern struct nfs_server *nfs_create_server(struct nfs_mount_info *,
 191                                         struct nfs_subversion *);
 192 extern struct nfs_server *nfs4_create_server(
 193                                         struct nfs_mount_info *,
 194                                         struct nfs_subversion *);
 195 extern struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *,
 196                                                       struct nfs_fh *);
 197 extern void nfs_free_server(struct nfs_server *server);
 198 extern struct nfs_server *nfs_clone_server(struct nfs_server *,
 199                                            struct nfs_fh *,
 200                                            struct nfs_fattr *,
 201                                            rpc_authflavor_t);
 202 extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
 203 extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
 204 extern 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
 210 extern int __init nfs_fs_proc_init(void);
 211 extern void nfs_fs_proc_exit(void);
 212 #else
 213 static inline int nfs_fs_proc_init(void)
 214 {
 215         return 0;
 216 }
 217 static inline void nfs_fs_proc_exit(void)
 218 {
 219 }
 220 #endif
 221
 222 #ifdef CONFIG_NFS_V4_1
 223 int nfs_sockaddr_match_ipaddr(const struct sockaddr *, const struct sockaddr *);
 224 #endif
 225
 226 /* nfs3client.c */
 227 #if IS_ENABLED(CONFIG_NFS_V3)
 228 struct nfs_server *nfs3_create_server(struct nfs_mount_info *, struct nfs_subversion *);
 229 struct 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 */
 234 extern struct svc_version nfs4_callback_version1;
 235 extern struct svc_version nfs4_callback_version4;
 236
 237 struct nfs_pageio_descriptor;
 238 /* pagelist.c */
 239 extern int __init nfs_init_nfspagecache(void);
 240 extern void nfs_destroy_nfspagecache(void);
 241 extern int __init nfs_init_readpagecache(void);
 242 extern void nfs_destroy_readpagecache(void);
 243 extern int __init nfs_init_writepagecache(void);
 244 extern void nfs_destroy_writepagecache(void);
 245
 246 extern int __init nfs_init_directcache(void);
 247 extern void nfs_destroy_directcache(void);
 248 extern bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount);
 249 extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
 250                               struct nfs_pgio_header *hdr,
 251                               void (*release)(struct nfs_pgio_header *hdr));
 252 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
 253
 254 /* nfs2xdr.c */
 255 extern struct rpc_procinfo nfs_procedures[];
 256 extern int nfs2_decode_dirent(struct xdr_stream *,
 257                                 struct nfs_entry *, int);
 258
 259 /* nfs3xdr.c */
 260 extern struct rpc_procinfo nfs3_procedures[];
 261 extern int nfs3_decode_dirent(struct xdr_stream *,
 262                                 struct nfs_entry *, int);
 263
 264 /* nfs4xdr.c */
 265 #if IS_ENABLED(CONFIG_NFS_V4)
 266 extern int nfs4_decode_dirent(struct xdr_stream *,
 267                                 struct nfs_entry *, int);
 268 #endif
 269 #ifdef CONFIG_NFS_V4_1
 270 extern const u32 nfs41_maxread_overhead;
 271 extern const u32 nfs41_maxwrite_overhead;
 272 #endif
 273
 274 /* nfs4proc.c */
 275 #if IS_ENABLED(CONFIG_NFS_V4)
 276 extern struct rpc_procinfo nfs4_procedures[];
 277 #endif
 278
 279 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
 280
 281 /* proc.c */
 282 void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
 283 extern 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 */
 288 extern int nfs_access_cache_shrinker(struct shrinker *shrink,
 289                                         struct shrink_control *sc);
 290 struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
 291 int nfs_create(struct inode *, struct dentry *, umode_t, bool);
 292 int nfs_mkdir(struct inode *, struct dentry *, umode_t);
 293 int nfs_rmdir(struct inode *, struct dentry *);
 294 int nfs_unlink(struct inode *, struct dentry *);
 295 int nfs_symlink(struct inode *, struct dentry *, const char *);
 296 int nfs_link(struct dentry *, struct inode *, struct dentry *);
 297 int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
 298 int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
 299
 300 /* file.c */
 301 int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
 302 loff_t nfs_file_llseek(struct file *, loff_t, int);
 303 int nfs_file_flush(struct file *, fl_owner_t);
 304 ssize_t nfs_file_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
 305 ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
 306                              size_t, unsigned int);
 307 int nfs_file_mmap(struct file *, struct vm_area_struct *);
 308 ssize_t nfs_file_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
 309 int nfs_file_release(struct inode *, struct file *);
 310 int nfs_lock(struct file *, int, struct file_lock *);
 311 int nfs_flock(struct file *, int, struct file_lock *);
 312 ssize_t nfs_file_splice_write(struct pipe_inode_info *, struct file *, loff_t *,
 313                               size_t, unsigned int);
 314 int nfs_check_flags(int);
 315 int nfs_setlease(struct file *, long, struct file_lock **);
 316
 317 /* inode.c */
 318 extern struct workqueue_struct *nfsiod_workqueue;
 319 extern struct inode *nfs_alloc_inode(struct super_block *sb);
 320 extern void nfs_destroy_inode(struct inode *);
 321 extern int nfs_write_inode(struct inode *, struct writeback_control *);
 322 extern void nfs_clear_inode(struct inode *);
 323 extern void nfs_evict_inode(struct inode *);
 324 void nfs_zap_acl_cache(struct inode *inode);
 325 extern int nfs_wait_bit_killable(void *word);
 326
 327 /* super.c */
 328 extern const struct super_operations nfs_sops;
 329 extern struct file_system_type nfs_fs_type;
 330 extern struct file_system_type nfs_xdev_fs_type;
 331 #if IS_ENABLED(CONFIG_NFS_V4)
 332 extern struct file_system_type nfs4_xdev_fs_type;
 333 extern struct file_system_type nfs4_referral_fs_type;
 334 #endif
 335 struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
 336                         struct nfs_subversion *);
 337 void nfs_initialise_sb(struct super_block *);
 338 int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 339 int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 340 struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
 341                                    struct nfs_mount_info *, struct nfs_subversion *);
 342 struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
 343 struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
 344                 const char *, struct nfs_mount_info *);
 345 void nfs_kill_super(struct super_block *);
 346 void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
 347
 348 extern struct rpc_stat nfs_rpcstat;
 349
 350 extern int __init register_nfs_fs(void);
 351 extern void __exit unregister_nfs_fs(void);
 352 extern void nfs_sb_active(struct super_block *sb);
 353 extern void nfs_sb_deactive(struct super_block *sb);
 354
 355 /* namespace.c */
 356 extern char *nfs_path(char **p, struct dentry *dentry,
 357                       char *buffer, ssize_t buflen);
 358 extern struct vfsmount *nfs_d_automount(struct path *path);
 359 struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
 360                               struct nfs_fh *, struct nfs_fattr *);
 361 struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
 362                                  struct nfs_fattr *, rpc_authflavor_t);
 363
 364 /* getroot.c */
 365 extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
 366                                    const char *);
 367 #if IS_ENABLED(CONFIG_NFS_V4)
 368 extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
 369                                     const char *);
 370
 371 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh);
 372 #endif
 373
 374 struct nfs_pgio_completion_ops;
 375 /* read.c */
 376 extern struct nfs_read_header *nfs_readhdr_alloc(void);
 377 extern void nfs_readhdr_free(struct nfs_pgio_header *hdr);
 378 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
 379                         struct inode *inode,
 380                         const struct nfs_pgio_completion_ops *compl_ops);
 381 extern int nfs_initiate_read(struct rpc_clnt *clnt,
 382                              struct nfs_read_data *data,
 383                              const struct rpc_call_ops *call_ops, int flags);
 384 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
 385 extern int nfs_generic_pagein(struct nfs_pageio_descriptor *desc,
 386                               struct nfs_pgio_header *hdr);
 387 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
 388                         struct inode *inode,
 389                         const struct nfs_pgio_completion_ops *compl_ops);
 390 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
 391 extern void nfs_readdata_release(struct nfs_read_data *rdata);
 392
 393 /* super.c */
 394 void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
 395 void nfs_umount_begin(struct super_block *);
 396 int  nfs_statfs(struct dentry *, struct kstatfs *);
 397 int  nfs_show_options(struct seq_file *, struct dentry *);
 398 int  nfs_show_devname(struct seq_file *, struct dentry *);
 399 int  nfs_show_path(struct seq_file *, struct dentry *);
 400 int  nfs_show_stats(struct seq_file *, struct dentry *);
 401 void nfs_put_super(struct super_block *);
 402 int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 403
 404 /* write.c */
 405 extern 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);
 408 extern struct nfs_write_header *nfs_writehdr_alloc(void);
 409 extern void nfs_writehdr_free(struct nfs_pgio_header *hdr);
 410 extern int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
 411                              struct nfs_pgio_header *hdr);
 412 extern 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);
 415 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
 416 extern void nfs_writedata_release(struct nfs_write_data *wdata);
 417 extern void nfs_commit_free(struct nfs_commit_data *p);
 418 extern 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);
 422 extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
 423 extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
 424 extern 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);
 428 extern 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);
 432 int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
 433                          struct nfs_commit_info *cinfo, int max);
 434 int nfs_scan_commit(struct inode *inode, struct list_head *dst,
 435                     struct nfs_commit_info *cinfo);
 436 void nfs_mark_request_commit(struct nfs_page *req,
 437                              struct pnfs_layout_segment *lseg,
 438                              struct nfs_commit_info *cinfo);
 439 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
 440                             int how, struct nfs_commit_info *cinfo);
 441 void nfs_retry_commit(struct list_head *page_list,
 442                       struct pnfs_layout_segment *lseg,
 443                       struct nfs_commit_info *cinfo);
 444 void nfs_commitdata_release(struct nfs_commit_data *data);
 445 void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
 446                                  struct nfs_commit_info *cinfo);
 447 void nfs_request_remove_commit_list(struct nfs_page *req,
 448                                     struct nfs_commit_info *cinfo);
 449 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
 450                     struct inode *inode,
 451                     struct nfs_direct_req *dreq);
 452
 453 #ifdef CONFIG_MIGRATION
 454 extern 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 */
 461 void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
 462                               struct nfs_direct_req *dreq);
 463 static inline void nfs_inode_dio_wait(struct inode *inode)
 464 {
 465         inode_dio_wait(inode);
 466 }
 467
 468 /* nfs4proc.c */
 469 extern void __nfs4_read_done_cb(struct nfs_read_data *);
 470 extern 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);
 474 extern 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);
 480 extern 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  */
 490 static 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  */
 500 static inline
 501 unsigned 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  */
 520 static 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  */
 529 static inline
 530 unsigned 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  */
 543 static inline
 544 void 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  */
 554 static inline
 555 unsigned 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  */
 573 static inline
 574 unsigned 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  */
 583 static inline
 584 unsigned 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  */
 597 static inline
 598 u64 nfs_timespec_to_change_attr(const struct timespec *ts)
 599 {
 600         return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
 601 }