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         unsigned int            auth_flavor_len;
  92         rpc_authflavor_t        auth_flavors[1];
  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_init_timeout_values(struct rpc_timeout *, int, unsigned int, unsigned int);
 158 int nfs_init_server_rpcclient(struct nfs_server *, const struct rpc_timeout *t,
 159                 rpc_authflavor_t);
 160 struct nfs_server *nfs_alloc_server(void);
 161 void nfs_server_copy_userdata(struct nfs_server *, struct nfs_server *);
 162
 163 extern void nfs_cleanup_cb_ident_idr(struct net *);
 164 extern void nfs_put_client(struct nfs_client *);
 165 extern void nfs_free_client(struct nfs_client *);
 166 extern struct nfs_client *nfs4_find_client_ident(struct net *, int);
 167 extern struct nfs_client *
 168 nfs4_find_client_sessionid(struct net *, const struct sockaddr *,
 169                                 struct nfs4_sessionid *, u32);
 170 extern struct nfs_server *nfs_create_server(struct nfs_mount_info *,
 171                                         struct nfs_subversion *);
 172 extern struct nfs_server *nfs4_create_server(
 173                                         struct nfs_mount_info *,
 174                                         struct nfs_subversion *);
 175 extern struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *,
 176                                                       struct nfs_fh *);
 177 extern void nfs_free_server(struct nfs_server *server);
 178 extern struct nfs_server *nfs_clone_server(struct nfs_server *,
 179                                            struct nfs_fh *,
 180                                            struct nfs_fattr *,
 181                                            rpc_authflavor_t);
 182 extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
 183 extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
 184 extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
 185                                              const struct sockaddr *ds_addr,
 186                                              int ds_addrlen, int ds_proto,
 187                                              unsigned int ds_timeo,
 188                                              unsigned int ds_retrans);
 189 extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
 190                                                 struct inode *);
 191 #ifdef CONFIG_PROC_FS
 192 extern int __init nfs_fs_proc_init(void);
 193 extern void nfs_fs_proc_exit(void);
 194 #else
 195 static inline int nfs_fs_proc_init(void)
 196 {
 197         return 0;
 198 }
 199 static inline void nfs_fs_proc_exit(void)
 200 {
 201 }
 202 #endif
 203
 204 #ifdef CONFIG_NFS_V4_1
 205 int nfs_sockaddr_match_ipaddr(const struct sockaddr *, const struct sockaddr *);
 206 #endif
 207
 208 /* nfs3client.c */
 209 #if IS_ENABLED(CONFIG_NFS_V3)
 210 struct nfs_server *nfs3_create_server(struct nfs_mount_info *, struct nfs_subversion *);
 211 struct nfs_server *nfs3_clone_server(struct nfs_server *, struct nfs_fh *,
 212                                      struct nfs_fattr *, rpc_authflavor_t);
 213 #endif
 214
 215 /* callback_xdr.c */
 216 extern struct svc_version nfs4_callback_version1;
 217 extern struct svc_version nfs4_callback_version4;
 218
 219 struct nfs_pageio_descriptor;
 220 /* pagelist.c */
 221 extern int __init nfs_init_nfspagecache(void);
 222 extern void nfs_destroy_nfspagecache(void);
 223 extern int __init nfs_init_readpagecache(void);
 224 extern void nfs_destroy_readpagecache(void);
 225 extern int __init nfs_init_writepagecache(void);
 226 extern void nfs_destroy_writepagecache(void);
 227
 228 extern int __init nfs_init_directcache(void);
 229 extern void nfs_destroy_directcache(void);
 230 extern bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount);
 231 extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
 232                               struct nfs_pgio_header *hdr,
 233                               void (*release)(struct nfs_pgio_header *hdr));
 234 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
 235 int nfs_iocounter_wait(struct nfs_io_counter *c);
 236
 237 static inline void nfs_iocounter_init(struct nfs_io_counter *c)
 238 {
 239         c->flags = 0;
 240         atomic_set(&c->io_count, 0);
 241 }
 242
 243 /* nfs2xdr.c */
 244 extern struct rpc_procinfo nfs_procedures[];
 245 extern int nfs2_decode_dirent(struct xdr_stream *,
 246                                 struct nfs_entry *, int);
 247
 248 /* nfs3xdr.c */
 249 extern struct rpc_procinfo nfs3_procedures[];
 250 extern int nfs3_decode_dirent(struct xdr_stream *,
 251                                 struct nfs_entry *, int);
 252
 253 /* nfs4xdr.c */
 254 #if IS_ENABLED(CONFIG_NFS_V4)
 255 extern int nfs4_decode_dirent(struct xdr_stream *,
 256                                 struct nfs_entry *, int);
 257 #endif
 258 #ifdef CONFIG_NFS_V4_1
 259 extern const u32 nfs41_maxread_overhead;
 260 extern const u32 nfs41_maxwrite_overhead;
 261 extern const u32 nfs41_maxgetdevinfo_overhead;
 262 #endif
 263
 264 /* nfs4proc.c */
 265 #if IS_ENABLED(CONFIG_NFS_V4)
 266 extern struct rpc_procinfo nfs4_procedures[];
 267 #endif
 268
 269 /* proc.c */
 270 void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
 271 extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
 272                            const struct rpc_timeout *timeparms,
 273                            const char *ip_addr);
 274
 275 /* dir.c */
 276 extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
 277                                             struct shrink_control *sc);
 278 extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
 279                                            struct shrink_control *sc);
 280 struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
 281 int nfs_create(struct inode *, struct dentry *, umode_t, bool);
 282 int nfs_mkdir(struct inode *, struct dentry *, umode_t);
 283 int nfs_rmdir(struct inode *, struct dentry *);
 284 int nfs_unlink(struct inode *, struct dentry *);
 285 int nfs_symlink(struct inode *, struct dentry *, const char *);
 286 int nfs_link(struct dentry *, struct inode *, struct dentry *);
 287 int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
 288 int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
 289
 290 /* file.c */
 291 int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
 292 loff_t nfs_file_llseek(struct file *, loff_t, int);
 293 int nfs_file_flush(struct file *, fl_owner_t);
 294 ssize_t nfs_file_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
 295 ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
 296                              size_t, unsigned int);
 297 int nfs_file_mmap(struct file *, struct vm_area_struct *);
 298 ssize_t nfs_file_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
 299 int nfs_file_release(struct inode *, struct file *);
 300 int nfs_lock(struct file *, int, struct file_lock *);
 301 int nfs_flock(struct file *, int, struct file_lock *);
 302 ssize_t nfs_file_splice_write(struct pipe_inode_info *, struct file *, loff_t *,
 303                               size_t, unsigned int);
 304 int nfs_check_flags(int);
 305 int nfs_setlease(struct file *, long, struct file_lock **);
 306
 307 /* inode.c */
 308 extern struct workqueue_struct *nfsiod_workqueue;
 309 extern struct inode *nfs_alloc_inode(struct super_block *sb);
 310 extern void nfs_destroy_inode(struct inode *);
 311 extern int nfs_write_inode(struct inode *, struct writeback_control *);
 312 extern int nfs_drop_inode(struct inode *);
 313 extern void nfs_clear_inode(struct inode *);
 314 extern void nfs_evict_inode(struct inode *);
 315 void nfs_zap_acl_cache(struct inode *inode);
 316 extern int nfs_wait_bit_killable(void *word);
 317
 318 /* super.c */
 319 extern const struct super_operations nfs_sops;
 320 extern struct file_system_type nfs_fs_type;
 321 extern struct file_system_type nfs_xdev_fs_type;
 322 #if IS_ENABLED(CONFIG_NFS_V4)
 323 extern struct file_system_type nfs4_xdev_fs_type;
 324 extern struct file_system_type nfs4_referral_fs_type;
 325 #endif
 326 struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
 327                         struct nfs_subversion *);
 328 void nfs_initialise_sb(struct super_block *);
 329 int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 330 int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 331 struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
 332                                    struct nfs_mount_info *, struct nfs_subversion *);
 333 struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
 334 struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
 335                 const char *, struct nfs_mount_info *);
 336 void nfs_kill_super(struct super_block *);
 337 void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
 338
 339 extern struct rpc_stat nfs_rpcstat;
 340
 341 extern int __init register_nfs_fs(void);
 342 extern void __exit unregister_nfs_fs(void);
 343 extern void nfs_sb_active(struct super_block *sb);
 344 extern void nfs_sb_deactive(struct super_block *sb);
 345
 346 /* namespace.c */
 347 #define NFS_PATH_CANONICAL 1
 348 extern char *nfs_path(char **p, struct dentry *dentry,
 349                       char *buffer, ssize_t buflen, unsigned flags);
 350 extern struct vfsmount *nfs_d_automount(struct path *path);
 351 struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
 352                               struct nfs_fh *, struct nfs_fattr *);
 353 struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
 354                                  struct nfs_fattr *, rpc_authflavor_t);
 355
 356 /* getroot.c */
 357 extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
 358                                    const char *);
 359 #if IS_ENABLED(CONFIG_NFS_V4)
 360 extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
 361                                     const char *);
 362
 363 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool);
 364 #endif
 365
 366 struct nfs_pgio_completion_ops;
 367 /* read.c */
 368 extern struct nfs_read_header *nfs_readhdr_alloc(void);
 369 extern void nfs_readhdr_free(struct nfs_pgio_header *hdr);
 370 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
 371                         struct inode *inode,
 372                         const struct nfs_pgio_completion_ops *compl_ops);
 373 extern int nfs_initiate_read(struct rpc_clnt *clnt,
 374                              struct nfs_read_data *data,
 375                              const struct rpc_call_ops *call_ops, int flags);
 376 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
 377 extern int nfs_generic_pagein(struct nfs_pageio_descriptor *desc,
 378                               struct nfs_pgio_header *hdr);
 379 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
 380 extern void nfs_readdata_release(struct nfs_read_data *rdata);
 381
 382 /* super.c */
 383 void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
 384 void nfs_umount_begin(struct super_block *);
 385 int  nfs_statfs(struct dentry *, struct kstatfs *);
 386 int  nfs_show_options(struct seq_file *, struct dentry *);
 387 int  nfs_show_devname(struct seq_file *, struct dentry *);
 388 int  nfs_show_path(struct seq_file *, struct dentry *);
 389 int  nfs_show_stats(struct seq_file *, struct dentry *);
 390 void nfs_put_super(struct super_block *);
 391 int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 392
 393 /* write.c */
 394 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
 395                         struct inode *inode, int ioflags,
 396                         const struct nfs_pgio_completion_ops *compl_ops);
 397 extern struct nfs_write_header *nfs_writehdr_alloc(void);
 398 extern void nfs_writehdr_free(struct nfs_pgio_header *hdr);
 399 extern int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
 400                              struct nfs_pgio_header *hdr);
 401 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
 402 extern void nfs_writedata_release(struct nfs_write_data *wdata);
 403 extern void nfs_commit_free(struct nfs_commit_data *p);
 404 extern int nfs_initiate_write(struct rpc_clnt *clnt,
 405                               struct nfs_write_data *data,
 406                               const struct rpc_call_ops *call_ops,
 407                               int how, int flags);
 408 extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
 409 extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
 410 extern int nfs_initiate_commit(struct rpc_clnt *clnt,
 411                                struct nfs_commit_data *data,
 412                                const struct rpc_call_ops *call_ops,
 413                                int how, int flags);
 414 extern void nfs_init_commit(struct nfs_commit_data *data,
 415                             struct list_head *head,
 416                             struct pnfs_layout_segment *lseg,
 417                             struct nfs_commit_info *cinfo);
 418 int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
 419                          struct nfs_commit_info *cinfo, int max);
 420 int nfs_scan_commit(struct inode *inode, struct list_head *dst,
 421                     struct nfs_commit_info *cinfo);
 422 void nfs_mark_request_commit(struct nfs_page *req,
 423                              struct pnfs_layout_segment *lseg,
 424                              struct nfs_commit_info *cinfo);
 425 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
 426                             int how, struct nfs_commit_info *cinfo);
 427 void nfs_retry_commit(struct list_head *page_list,
 428                       struct pnfs_layout_segment *lseg,
 429                       struct nfs_commit_info *cinfo);
 430 void nfs_commitdata_release(struct nfs_commit_data *data);
 431 void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
 432                                  struct nfs_commit_info *cinfo);
 433 void nfs_request_remove_commit_list(struct nfs_page *req,
 434                                     struct nfs_commit_info *cinfo);
 435 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
 436                     struct inode *inode,
 437                     struct nfs_direct_req *dreq);
 438 int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
 439 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
 440
 441 #ifdef CONFIG_MIGRATION
 442 extern int nfs_migrate_page(struct address_space *,
 443                 struct page *, struct page *, enum migrate_mode);
 444 #else
 445 #define nfs_migrate_page NULL
 446 #endif
 447
 448 /* direct.c */
 449 void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
 450                               struct nfs_direct_req *dreq);
 451 static inline void nfs_inode_dio_wait(struct inode *inode)
 452 {
 453         inode_dio_wait(inode);
 454 }
 455 extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
 456
 457 /* nfs4proc.c */
 458 extern void __nfs4_read_done_cb(struct nfs_read_data *);
 459 extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
 460                             const struct rpc_timeout *timeparms,
 461                             const char *ip_addr);
 462 extern int nfs40_walk_client_list(struct nfs_client *clp,
 463                                 struct nfs_client **result,
 464                                 struct rpc_cred *cred);
 465 extern int nfs41_walk_client_list(struct nfs_client *clp,
 466                                 struct nfs_client **result,
 467                                 struct rpc_cred *cred);
 468
 469 /*
 470  * Determine the device name as a string
 471  */
 472 static inline char *nfs_devname(struct dentry *dentry,
 473                                 char *buffer, ssize_t buflen)
 474 {
 475         char *dummy;
 476         return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
 477 }
 478
 479 /*
 480  * Determine the actual block size (and log2 thereof)
 481  */
 482 static inline
 483 unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
 484 {
 485         /* make sure blocksize is a power of two */
 486         if ((bsize & (bsize - 1)) || nrbitsp) {
 487                 unsigned char   nrbits;
 488
 489                 for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
 490                         ;
 491                 bsize = 1 << nrbits;
 492                 if (nrbitsp)
 493                         *nrbitsp = nrbits;
 494         }
 495
 496         return bsize;
 497 }
 498
 499 /*
 500  * Calculate the number of 512byte blocks used.
 501  */
 502 static inline blkcnt_t nfs_calc_block_size(u64 tsize)
 503 {
 504         blkcnt_t used = (tsize + 511) >> 9;
 505         return (used > ULONG_MAX) ? ULONG_MAX : used;
 506 }
 507
 508 /*
 509  * Compute and set NFS server blocksize
 510  */
 511 static inline
 512 unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
 513 {
 514         if (bsize < NFS_MIN_FILE_IO_SIZE)
 515                 bsize = NFS_DEF_FILE_IO_SIZE;
 516         else if (bsize >= NFS_MAX_FILE_IO_SIZE)
 517                 bsize = NFS_MAX_FILE_IO_SIZE;
 518
 519         return nfs_block_bits(bsize, nrbitsp);
 520 }
 521
 522 /*
 523  * Determine the maximum file size for a superblock
 524  */
 525 static inline
 526 void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
 527 {
 528         sb->s_maxbytes = (loff_t)maxfilesize;
 529         if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
 530                 sb->s_maxbytes = MAX_LFS_FILESIZE;
 531 }
 532
 533 /*
 534  * Determine the number of bytes of data the page contains
 535  */
 536 static inline
 537 unsigned int nfs_page_length(struct page *page)
 538 {
 539         loff_t i_size = i_size_read(page_file_mapping(page)->host);
 540
 541         if (i_size > 0) {
 542                 pgoff_t page_index = page_file_index(page);
 543                 pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
 544                 if (page_index < end_index)
 545                         return PAGE_CACHE_SIZE;
 546                 if (page_index == end_index)
 547                         return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
 548         }
 549         return 0;
 550 }
 551
 552 /*
 553  * Convert a umode to a dirent->d_type
 554  */
 555 static inline
 556 unsigned char nfs_umode_to_dtype(umode_t mode)
 557 {
 558         return (mode >> 12) & 15;
 559 }
 560
 561 /*
 562  * Determine the number of pages in an array of length 'len' and
 563  * with a base offset of 'base'
 564  */
 565 static inline
 566 unsigned int nfs_page_array_len(unsigned int base, size_t len)
 567 {
 568         return ((unsigned long)len + (unsigned long)base +
 569                 PAGE_SIZE - 1) >> PAGE_SHIFT;
 570 }
 571
 572 /*
 573  * Convert a struct timespec into a 64-bit change attribute
 574  *
 575  * This does approximately the same thing as timespec_to_ns(),
 576  * but for calculation efficiency, we multiply the seconds by
 577  * 1024*1024*1024.
 578  */
 579 static inline
 580 u64 nfs_timespec_to_change_attr(const struct timespec *ts)
 581 {
 582         return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
 583 }
 584
 585 #ifdef CONFIG_CRC32
 586 /**
 587  * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
 588  * @fh - pointer to filehandle
 589  *
 590  * returns a crc32 hash for the filehandle that is compatible with
 591  * the one displayed by "wireshark".
 592  */
 593 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
 594 {
 595         return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
 596 }
 597 #else
 598 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
 599 {
 600         return 0;
 601 }
 602 #endif