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