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                                         struct net *net);
 181 extern void nfs_free_server(struct nfs_server *server);
 182 extern struct nfs_server *nfs_clone_server(struct nfs_server *,
 183                                            struct nfs_fh *,
 184                                            struct nfs_fattr *,
 185                                            rpc_authflavor_t);
 186 extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
 187 extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
 188 extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
 189                                              const struct sockaddr *ds_addr,
 190                                              int ds_addrlen, int ds_proto,
 191                                              unsigned int ds_timeo,
 192                                              unsigned int ds_retrans);
 193 extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
 194                                                 struct inode *);
 195 #ifdef CONFIG_PROC_FS
 196 extern int __init nfs_fs_proc_init(void);
 197 extern void nfs_fs_proc_exit(void);
 198 extern int nfs_fs_proc_net_init(struct net *net);
 199 extern void nfs_fs_proc_net_exit(struct net *net);
 200 #else
 201 static inline int nfs_fs_proc_net_init(struct net *net)
 202 {
 203         return 0;
 204 }
 205 static inline void nfs_fs_proc_net_exit(struct net *net)
 206 {
 207 }
 208 static inline int nfs_fs_proc_init(void)
 209 {
 210         return 0;
 211 }
 212 static inline void nfs_fs_proc_exit(void)
 213 {
 214 }
 215 #endif
 216
 217 #ifdef CONFIG_NFS_V4_1
 218 int nfs_sockaddr_match_ipaddr(const struct sockaddr *, const struct sockaddr *);
 219 #endif
 220
 221 /* nfs3client.c */
 222 #if IS_ENABLED(CONFIG_NFS_V3)
 223 struct nfs_server *nfs3_create_server(struct nfs_mount_info *, struct nfs_subversion *);
 224 struct nfs_server *nfs3_clone_server(struct nfs_server *, struct nfs_fh *,
 225                                      struct nfs_fattr *, rpc_authflavor_t);
 226 #endif
 227
 228 /* callback_xdr.c */
 229 extern struct svc_version nfs4_callback_version1;
 230 extern struct svc_version nfs4_callback_version4;
 231
 232 struct nfs_pageio_descriptor;
 233 /* pagelist.c */
 234 extern int __init nfs_init_nfspagecache(void);
 235 extern void nfs_destroy_nfspagecache(void);
 236 extern int __init nfs_init_readpagecache(void);
 237 extern void nfs_destroy_readpagecache(void);
 238 extern int __init nfs_init_writepagecache(void);
 239 extern void nfs_destroy_writepagecache(void);
 240
 241 extern int __init nfs_init_directcache(void);
 242 extern void nfs_destroy_directcache(void);
 243 extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
 244                               struct nfs_pgio_header *hdr,
 245                               void (*release)(struct nfs_pgio_header *hdr));
 246 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
 247 int nfs_iocounter_wait(struct nfs_io_counter *c);
 248
 249 extern const struct nfs_pageio_ops nfs_pgio_rw_ops;
 250 struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *);
 251 void nfs_pgio_header_free(struct nfs_pgio_header *);
 252 void nfs_pgio_data_destroy(struct nfs_pgio_header *);
 253 int nfs_generic_pgio(struct nfs_pageio_descriptor *, struct nfs_pgio_header *);
 254 int nfs_initiate_pgio(struct rpc_clnt *, struct nfs_pgio_header *,
 255                       const struct rpc_call_ops *, int, int);
 256 void nfs_free_request(struct nfs_page *req);
 257
 258 static inline void nfs_iocounter_init(struct nfs_io_counter *c)
 259 {
 260         c->flags = 0;
 261         atomic_set(&c->io_count, 0);
 262 }
 263
 264 /* nfs2xdr.c */
 265 extern struct rpc_procinfo nfs_procedures[];
 266 extern int nfs2_decode_dirent(struct xdr_stream *,
 267                                 struct nfs_entry *, int);
 268
 269 /* nfs3xdr.c */
 270 extern struct rpc_procinfo nfs3_procedures[];
 271 extern int nfs3_decode_dirent(struct xdr_stream *,
 272                                 struct nfs_entry *, int);
 273
 274 /* nfs4xdr.c */
 275 #if IS_ENABLED(CONFIG_NFS_V4)
 276 extern int nfs4_decode_dirent(struct xdr_stream *,
 277                                 struct nfs_entry *, int);
 278 #endif
 279 #ifdef CONFIG_NFS_V4_1
 280 extern const u32 nfs41_maxread_overhead;
 281 extern const u32 nfs41_maxwrite_overhead;
 282 extern const u32 nfs41_maxgetdevinfo_overhead;
 283 #endif
 284
 285 /* nfs4proc.c */
 286 #if IS_ENABLED(CONFIG_NFS_V4)
 287 extern struct rpc_procinfo nfs4_procedures[];
 288 #endif
 289
 290 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
 291 extern struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags);
 292 static inline void nfs4_label_free(struct nfs4_label *label)
 293 {
 294         if (label) {
 295                 kfree(label->label);
 296                 kfree(label);
 297         }
 298         return;
 299 }
 300
 301 static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
 302 {
 303         if (nfs_server_capable(&nfsi->vfs_inode, NFS_CAP_SECURITY_LABEL))
 304                 nfsi->cache_validity |= NFS_INO_INVALID_LABEL;
 305 }
 306 #else
 307 static inline struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags) { return NULL; }
 308 static inline void nfs4_label_free(void *label) {}
 309 static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
 310 {
 311 }
 312 #endif /* CONFIG_NFS_V4_SECURITY_LABEL */
 313
 314 /* proc.c */
 315 void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
 316 extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
 317                            const struct rpc_timeout *timeparms,
 318                            const char *ip_addr);
 319
 320 /* dir.c */
 321 extern void nfs_force_use_readdirplus(struct inode *dir);
 322 extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
 323                                             struct shrink_control *sc);
 324 extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
 325                                            struct shrink_control *sc);
 326 struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
 327 int nfs_create(struct inode *, struct dentry *, umode_t, bool);
 328 int nfs_mkdir(struct inode *, struct dentry *, umode_t);
 329 int nfs_rmdir(struct inode *, struct dentry *);
 330 int nfs_unlink(struct inode *, struct dentry *);
 331 int nfs_symlink(struct inode *, struct dentry *, const char *);
 332 int nfs_link(struct dentry *, struct inode *, struct dentry *);
 333 int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
 334 int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
 335
 336 /* file.c */
 337 int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
 338 loff_t nfs_file_llseek(struct file *, loff_t, int);
 339 int nfs_file_flush(struct file *, fl_owner_t);
 340 ssize_t nfs_file_read(struct kiocb *, struct iov_iter *);
 341 ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
 342                              size_t, unsigned int);
 343 int nfs_file_mmap(struct file *, struct vm_area_struct *);
 344 ssize_t nfs_file_write(struct kiocb *, struct iov_iter *);
 345 int nfs_file_release(struct inode *, struct file *);
 346 int nfs_lock(struct file *, int, struct file_lock *);
 347 int nfs_flock(struct file *, int, struct file_lock *);
 348 int nfs_check_flags(int);
 349 int nfs_setlease(struct file *, long, struct file_lock **);
 350
 351 /* inode.c */
 352 extern struct workqueue_struct *nfsiod_workqueue;
 353 extern struct inode *nfs_alloc_inode(struct super_block *sb);
 354 extern void nfs_destroy_inode(struct inode *);
 355 extern int nfs_write_inode(struct inode *, struct writeback_control *);
 356 extern int nfs_drop_inode(struct inode *);
 357 extern void nfs_clear_inode(struct inode *);
 358 extern void nfs_evict_inode(struct inode *);
 359 void nfs_zap_acl_cache(struct inode *inode);
 360 extern int nfs_wait_bit_killable(struct wait_bit_key *key);
 361
 362 /* super.c */
 363 extern const struct super_operations nfs_sops;
 364 extern struct file_system_type nfs_fs_type;
 365 extern struct file_system_type nfs_xdev_fs_type;
 366 #if IS_ENABLED(CONFIG_NFS_V4)
 367 extern struct file_system_type nfs4_xdev_fs_type;
 368 extern struct file_system_type nfs4_referral_fs_type;
 369 #endif
 370 bool nfs_auth_info_match(const struct nfs_auth_info *, rpc_authflavor_t);
 371 struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
 372                         struct nfs_subversion *);
 373 void nfs_initialise_sb(struct super_block *);
 374 int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 375 int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 376 struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
 377                                    struct nfs_mount_info *, struct nfs_subversion *);
 378 struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
 379 struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
 380                 const char *, struct nfs_mount_info *);
 381 void nfs_kill_super(struct super_block *);
 382 void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
 383
 384 extern struct rpc_stat nfs_rpcstat;
 385
 386 extern int __init register_nfs_fs(void);
 387 extern void __exit unregister_nfs_fs(void);
 388 extern void nfs_sb_active(struct super_block *sb);
 389 extern void nfs_sb_deactive(struct super_block *sb);
 390
 391 /* namespace.c */
 392 #define NFS_PATH_CANONICAL 1
 393 extern char *nfs_path(char **p, struct dentry *dentry,
 394                       char *buffer, ssize_t buflen, unsigned flags);
 395 extern struct vfsmount *nfs_d_automount(struct path *path);
 396 struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
 397                               struct nfs_fh *, struct nfs_fattr *);
 398 struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
 399                                  struct nfs_fattr *, rpc_authflavor_t);
 400
 401 /* getroot.c */
 402 extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
 403                                    const char *);
 404 #if IS_ENABLED(CONFIG_NFS_V4)
 405 extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
 406                                     const char *);
 407
 408 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool);
 409 #endif
 410
 411 struct nfs_pgio_completion_ops;
 412 /* read.c */
 413 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
 414                         struct inode *inode, bool force_mds,
 415                         const struct nfs_pgio_completion_ops *compl_ops);
 416 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
 417 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
 418
 419 /* super.c */
 420 void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
 421 void nfs_umount_begin(struct super_block *);
 422 int  nfs_statfs(struct dentry *, struct kstatfs *);
 423 int  nfs_show_options(struct seq_file *, struct dentry *);
 424 int  nfs_show_devname(struct seq_file *, struct dentry *);
 425 int  nfs_show_path(struct seq_file *, struct dentry *);
 426 int  nfs_show_stats(struct seq_file *, struct dentry *);
 427 void nfs_put_super(struct super_block *);
 428 int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 429
 430 /* write.c */
 431 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
 432                         struct inode *inode, int ioflags, bool force_mds,
 433                         const struct nfs_pgio_completion_ops *compl_ops);
 434 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
 435 extern void nfs_commit_free(struct nfs_commit_data *p);
 436 extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
 437 extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
 438 extern int nfs_initiate_commit(struct rpc_clnt *clnt,
 439                                struct nfs_commit_data *data,
 440                                const struct rpc_call_ops *call_ops,
 441                                int how, int flags);
 442 extern void nfs_init_commit(struct nfs_commit_data *data,
 443                             struct list_head *head,
 444                             struct pnfs_layout_segment *lseg,
 445                             struct nfs_commit_info *cinfo);
 446 int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
 447                          struct nfs_commit_info *cinfo, int max);
 448 unsigned long nfs_reqs_to_commit(struct nfs_commit_info *);
 449 int nfs_scan_commit(struct inode *inode, struct list_head *dst,
 450                     struct nfs_commit_info *cinfo);
 451 void nfs_mark_request_commit(struct nfs_page *req,
 452                              struct pnfs_layout_segment *lseg,
 453                              struct nfs_commit_info *cinfo);
 454 int nfs_write_need_commit(struct nfs_pgio_header *);
 455 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
 456                             int how, struct nfs_commit_info *cinfo);
 457 void nfs_retry_commit(struct list_head *page_list,
 458                       struct pnfs_layout_segment *lseg,
 459                       struct nfs_commit_info *cinfo);
 460 void nfs_commitdata_release(struct nfs_commit_data *data);
 461 void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
 462                                  struct nfs_commit_info *cinfo);
 463 void nfs_request_remove_commit_list(struct nfs_page *req,
 464                                     struct nfs_commit_info *cinfo);
 465 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
 466                     struct inode *inode,
 467                     struct nfs_direct_req *dreq);
 468 int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
 469 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
 470
 471 #ifdef CONFIG_MIGRATION
 472 extern int nfs_migrate_page(struct address_space *,
 473                 struct page *, struct page *, enum migrate_mode);
 474 #else
 475 #define nfs_migrate_page NULL
 476 #endif
 477
 478 /* unlink.c */
 479 extern struct rpc_task *
 480 nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
 481                  struct dentry *old_dentry, struct dentry *new_dentry,
 482                  void (*complete)(struct rpc_task *, struct nfs_renamedata *));
 483 extern int nfs_sillyrename(struct inode *dir, struct dentry *dentry);
 484
 485 /* direct.c */
 486 void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
 487                               struct nfs_direct_req *dreq);
 488 static inline void nfs_inode_dio_wait(struct inode *inode)
 489 {
 490         inode_dio_wait(inode);
 491 }
 492 extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
 493
 494 /* nfs4proc.c */
 495 extern void __nfs4_read_done_cb(struct nfs_pgio_header *);
 496 extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
 497                             const struct rpc_timeout *timeparms,
 498                             const char *ip_addr);
 499 extern int nfs40_walk_client_list(struct nfs_client *clp,
 500                                 struct nfs_client **result,
 501                                 struct rpc_cred *cred);
 502 extern int nfs41_walk_client_list(struct nfs_client *clp,
 503                                 struct nfs_client **result,
 504                                 struct rpc_cred *cred);
 505
 506 /*
 507  * Determine the device name as a string
 508  */
 509 static inline char *nfs_devname(struct dentry *dentry,
 510                                 char *buffer, ssize_t buflen)
 511 {
 512         char *dummy;
 513         return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
 514 }
 515
 516 /*
 517  * Determine the actual block size (and log2 thereof)
 518  */
 519 static inline
 520 unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
 521 {
 522         /* make sure blocksize is a power of two */
 523         if ((bsize & (bsize - 1)) || nrbitsp) {
 524                 unsigned char   nrbits;
 525
 526                 for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
 527                         ;
 528                 bsize = 1 << nrbits;
 529                 if (nrbitsp)
 530                         *nrbitsp = nrbits;
 531         }
 532
 533         return bsize;
 534 }
 535
 536 /*
 537  * Calculate the number of 512byte blocks used.
 538  */
 539 static inline blkcnt_t nfs_calc_block_size(u64 tsize)
 540 {
 541         blkcnt_t used = (tsize + 511) >> 9;
 542         return (used > ULONG_MAX) ? ULONG_MAX : used;
 543 }
 544
 545 /*
 546  * Compute and set NFS server blocksize
 547  */
 548 static inline
 549 unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
 550 {
 551         if (bsize < NFS_MIN_FILE_IO_SIZE)
 552                 bsize = NFS_DEF_FILE_IO_SIZE;
 553         else if (bsize >= NFS_MAX_FILE_IO_SIZE)
 554                 bsize = NFS_MAX_FILE_IO_SIZE;
 555
 556         return nfs_block_bits(bsize, nrbitsp);
 557 }
 558
 559 /*
 560  * Determine the maximum file size for a superblock
 561  */
 562 static inline
 563 void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
 564 {
 565         sb->s_maxbytes = (loff_t)maxfilesize;
 566         if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
 567                 sb->s_maxbytes = MAX_LFS_FILESIZE;
 568 }
 569
 570 /*
 571  * Determine the number of bytes of data the page contains
 572  */
 573 static inline
 574 unsigned int nfs_page_length(struct page *page)
 575 {
 576         loff_t i_size = i_size_read(page_file_mapping(page)->host);
 577
 578         if (i_size > 0) {
 579                 pgoff_t page_index = page_file_index(page);
 580                 pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
 581                 if (page_index < end_index)
 582                         return PAGE_CACHE_SIZE;
 583                 if (page_index == end_index)
 584                         return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
 585         }
 586         return 0;
 587 }
 588
 589 /*
 590  * Convert a umode to a dirent->d_type
 591  */
 592 static inline
 593 unsigned char nfs_umode_to_dtype(umode_t mode)
 594 {
 595         return (mode >> 12) & 15;
 596 }
 597
 598 /*
 599  * Determine the number of pages in an array of length 'len' and
 600  * with a base offset of 'base'
 601  */
 602 static inline
 603 unsigned int nfs_page_array_len(unsigned int base, size_t len)
 604 {
 605         return ((unsigned long)len + (unsigned long)base +
 606                 PAGE_SIZE - 1) >> PAGE_SHIFT;
 607 }
 608
 609 /*
 610  * Convert a struct timespec into a 64-bit change attribute
 611  *
 612  * This does approximately the same thing as timespec_to_ns(),
 613  * but for calculation efficiency, we multiply the seconds by
 614  * 1024*1024*1024.
 615  */
 616 static inline
 617 u64 nfs_timespec_to_change_attr(const struct timespec *ts)
 618 {
 619         return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
 620 }
 621
 622 #ifdef CONFIG_CRC32
 623 /**
 624  * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
 625  * @fh - pointer to filehandle
 626  *
 627  * returns a crc32 hash for the filehandle that is compatible with
 628  * the one displayed by "wireshark".
 629  */
 630 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
 631 {
 632         return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
 633 }
 634 #else
 635 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
 636 {
 637         return 0;
 638 }
 639 #endif