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 #include <linux/nfs_page.h>
  10
  11 #define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
  12
  13 struct nfs_string;
  14
  15 /* Maximum number of readahead requests
  16  * FIXME: this should really be a sysctl so that users may tune it to suit
  17  *        their needs. People that do NFS over a slow network, might for
  18  *        instance want to reduce it to something closer to 1 for improved
  19  *        interactive response.
  20  */
  21 #define NFS_MAX_READAHEAD       (RPC_DEF_SLOT_TABLE - 1)
  22
  23 static inline void nfs_attr_check_mountpoint(struct super_block *parent, struct nfs_fattr *fattr)
  24 {
  25         if (!nfs_fsid_equal(&NFS_SB(parent)->fsid, &fattr->fsid))
  26                 fattr->valid |= NFS_ATTR_FATTR_MOUNTPOINT;
  27 }
  28
  29 static inline int nfs_attr_use_mounted_on_fileid(struct nfs_fattr *fattr)
  30 {
  31         if (((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) == 0) ||
  32             (((fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT) == 0) &&
  33              ((fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) == 0)))
  34                 return 0;
  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         struct nfs_auth_info    auth_info;
  91         rpc_authflavor_t        selected_flavor;
  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_server_remove_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 int nfs4_update_server(struct nfs_server *server, const char *hostname,
 178                                         struct sockaddr *sap, size_t salen,
 179                                         struct net *net);
 180 extern void nfs_free_server(struct nfs_server *server);
 181 extern struct nfs_server *nfs_clone_server(struct nfs_server *,
 182                                            struct nfs_fh *,
 183                                            struct nfs_fattr *,
 184                                            rpc_authflavor_t);
 185 extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
 186 extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
 187 extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
 188                                              const struct sockaddr *ds_addr,
 189                                              int ds_addrlen, int ds_proto,
 190                                              unsigned int ds_timeo,
 191                                              unsigned int ds_retrans,
 192                                              u32 minor_version,
 193                                              rpc_authflavor_t au_flavor);
 194 extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
 195                                                 struct inode *);
 196 extern struct nfs_client *nfs3_set_ds_client(struct nfs_client *mds_clp,
 197                         const struct sockaddr *ds_addr, int ds_addrlen,
 198                         int ds_proto, unsigned int ds_timeo,
 199                         unsigned int ds_retrans, rpc_authflavor_t au_flavor);
 200 #ifdef CONFIG_PROC_FS
 201 extern int __init nfs_fs_proc_init(void);
 202 extern void nfs_fs_proc_exit(void);
 203 extern int nfs_fs_proc_net_init(struct net *net);
 204 extern void nfs_fs_proc_net_exit(struct net *net);
 205 #else
 206 static inline int nfs_fs_proc_net_init(struct net *net)
 207 {
 208         return 0;
 209 }
 210 static inline void nfs_fs_proc_net_exit(struct net *net)
 211 {
 212 }
 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 /* callback_xdr.c */
 227 extern struct svc_version nfs4_callback_version1;
 228 extern struct svc_version nfs4_callback_version4;
 229
 230 struct nfs_pageio_descriptor;
 231 /* pagelist.c */
 232 extern int __init nfs_init_nfspagecache(void);
 233 extern void nfs_destroy_nfspagecache(void);
 234 extern int __init nfs_init_readpagecache(void);
 235 extern void nfs_destroy_readpagecache(void);
 236 extern int __init nfs_init_writepagecache(void);
 237 extern void nfs_destroy_writepagecache(void);
 238
 239 extern int __init nfs_init_directcache(void);
 240 extern void nfs_destroy_directcache(void);
 241 extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
 242                               struct nfs_pgio_header *hdr,
 243                               void (*release)(struct nfs_pgio_header *hdr));
 244 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
 245 int nfs_iocounter_wait(struct nfs_io_counter *c);
 246
 247 extern const struct nfs_pageio_ops nfs_pgio_rw_ops;
 248 struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *);
 249 void nfs_pgio_header_free(struct nfs_pgio_header *);
 250 void nfs_pgio_data_destroy(struct nfs_pgio_header *);
 251 int nfs_generic_pgio(struct nfs_pageio_descriptor *, struct nfs_pgio_header *);
 252 int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
 253                       struct rpc_cred *cred, const struct nfs_rpc_ops *rpc_ops,
 254                       const struct rpc_call_ops *call_ops, int how, int flags);
 255 void nfs_free_request(struct nfs_page *req);
 256 struct nfs_pgio_mirror *
 257 nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc);
 258
 259 static inline void nfs_iocounter_init(struct nfs_io_counter *c)
 260 {
 261         c->flags = 0;
 262         atomic_set(&c->io_count, 0);
 263 }
 264
 265 static inline bool nfs_pgio_has_mirroring(struct nfs_pageio_descriptor *desc)
 266 {
 267         WARN_ON_ONCE(desc->pg_mirror_count < 1);
 268         return desc->pg_mirror_count > 1;
 269 }
 270
 271 /* nfs2xdr.c */
 272 extern struct rpc_procinfo nfs_procedures[];
 273 extern int nfs2_decode_dirent(struct xdr_stream *,
 274                                 struct nfs_entry *, int);
 275
 276 /* nfs3xdr.c */
 277 extern struct rpc_procinfo nfs3_procedures[];
 278 extern int nfs3_decode_dirent(struct xdr_stream *,
 279                                 struct nfs_entry *, int);
 280
 281 /* nfs4xdr.c */
 282 #if IS_ENABLED(CONFIG_NFS_V4)
 283 extern int nfs4_decode_dirent(struct xdr_stream *,
 284                                 struct nfs_entry *, int);
 285 #endif
 286 #ifdef CONFIG_NFS_V4_1
 287 extern const u32 nfs41_maxread_overhead;
 288 extern const u32 nfs41_maxwrite_overhead;
 289 extern const u32 nfs41_maxgetdevinfo_overhead;
 290 #endif
 291
 292 /* nfs4proc.c */
 293 #if IS_ENABLED(CONFIG_NFS_V4)
 294 extern struct rpc_procinfo nfs4_procedures[];
 295 #endif
 296
 297 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
 298 extern struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags);
 299 static inline void nfs4_label_free(struct nfs4_label *label)
 300 {
 301         if (label) {
 302                 kfree(label->label);
 303                 kfree(label);
 304         }
 305         return;
 306 }
 307
 308 static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
 309 {
 310         if (nfs_server_capable(&nfsi->vfs_inode, NFS_CAP_SECURITY_LABEL))
 311                 nfsi->cache_validity |= NFS_INO_INVALID_LABEL;
 312 }
 313 #else
 314 static inline struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags) { return NULL; }
 315 static inline void nfs4_label_free(void *label) {}
 316 static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
 317 {
 318 }
 319 #endif /* CONFIG_NFS_V4_SECURITY_LABEL */
 320
 321 /* proc.c */
 322 void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
 323 extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
 324                            const struct rpc_timeout *timeparms,
 325                            const char *ip_addr);
 326
 327 /* dir.c */
 328 extern void nfs_force_use_readdirplus(struct inode *dir);
 329 extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
 330                                             struct shrink_control *sc);
 331 extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
 332                                            struct shrink_control *sc);
 333 struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
 334 int nfs_create(struct inode *, struct dentry *, umode_t, bool);
 335 int nfs_mkdir(struct inode *, struct dentry *, umode_t);
 336 int nfs_rmdir(struct inode *, struct dentry *);
 337 int nfs_unlink(struct inode *, struct dentry *);
 338 int nfs_symlink(struct inode *, struct dentry *, const char *);
 339 int nfs_link(struct dentry *, struct inode *, struct dentry *);
 340 int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
 341 int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
 342
 343 /* file.c */
 344 int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
 345 loff_t nfs_file_llseek(struct file *, loff_t, int);
 346 int nfs_file_flush(struct file *, fl_owner_t);
 347 ssize_t nfs_file_read(struct kiocb *, struct iov_iter *);
 348 ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
 349                              size_t, unsigned int);
 350 int nfs_file_mmap(struct file *, struct vm_area_struct *);
 351 ssize_t nfs_file_write(struct kiocb *, struct iov_iter *);
 352 int nfs_file_release(struct inode *, struct file *);
 353 int nfs_lock(struct file *, int, struct file_lock *);
 354 int nfs_flock(struct file *, int, struct file_lock *);
 355 int nfs_check_flags(int);
 356
 357 /* inode.c */
 358 extern struct workqueue_struct *nfsiod_workqueue;
 359 extern struct inode *nfs_alloc_inode(struct super_block *sb);
 360 extern void nfs_destroy_inode(struct inode *);
 361 extern int nfs_write_inode(struct inode *, struct writeback_control *);
 362 extern int nfs_drop_inode(struct inode *);
 363 extern void nfs_clear_inode(struct inode *);
 364 extern void nfs_evict_inode(struct inode *);
 365 void nfs_zap_acl_cache(struct inode *inode);
 366 extern int nfs_wait_bit_killable(struct wait_bit_key *key);
 367
 368 /* super.c */
 369 extern const struct super_operations nfs_sops;
 370 extern struct file_system_type nfs_fs_type;
 371 extern struct file_system_type nfs_xdev_fs_type;
 372 #if IS_ENABLED(CONFIG_NFS_V4)
 373 extern struct file_system_type nfs4_xdev_fs_type;
 374 extern struct file_system_type nfs4_referral_fs_type;
 375 #endif
 376 bool nfs_auth_info_match(const struct nfs_auth_info *, rpc_authflavor_t);
 377 struct dentry *nfs_try_mount(int, const char *, struct nfs_mount_info *,
 378                         struct nfs_subversion *);
 379 void nfs_initialise_sb(struct super_block *);
 380 int nfs_set_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 381 int nfs_clone_sb_security(struct super_block *, struct dentry *, struct nfs_mount_info *);
 382 struct dentry *nfs_fs_mount_common(struct nfs_server *, int, const char *,
 383                                    struct nfs_mount_info *, struct nfs_subversion *);
 384 struct dentry *nfs_fs_mount(struct file_system_type *, int, const char *, void *);
 385 struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
 386                 const char *, struct nfs_mount_info *);
 387 void nfs_kill_super(struct super_block *);
 388 void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
 389
 390 extern struct rpc_stat nfs_rpcstat;
 391
 392 extern int __init register_nfs_fs(void);
 393 extern void __exit unregister_nfs_fs(void);
 394 extern bool nfs_sb_active(struct super_block *sb);
 395 extern void nfs_sb_deactive(struct super_block *sb);
 396
 397 /* namespace.c */
 398 #define NFS_PATH_CANONICAL 1
 399 extern char *nfs_path(char **p, struct dentry *dentry,
 400                       char *buffer, ssize_t buflen, unsigned flags);
 401 extern struct vfsmount *nfs_d_automount(struct path *path);
 402 struct vfsmount *nfs_submount(struct nfs_server *, struct dentry *,
 403                               struct nfs_fh *, struct nfs_fattr *);
 404 struct vfsmount *nfs_do_submount(struct dentry *, struct nfs_fh *,
 405                                  struct nfs_fattr *, rpc_authflavor_t);
 406
 407 /* getroot.c */
 408 extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
 409                                    const char *);
 410 #if IS_ENABLED(CONFIG_NFS_V4)
 411 extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
 412                                     const char *);
 413
 414 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool);
 415 #endif
 416
 417 struct nfs_pgio_completion_ops;
 418 /* read.c */
 419 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
 420                         struct inode *inode, bool force_mds,
 421                         const struct nfs_pgio_completion_ops *compl_ops);
 422 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
 423 extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
 424
 425 /* super.c */
 426 void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
 427 void nfs_umount_begin(struct super_block *);
 428 int  nfs_statfs(struct dentry *, struct kstatfs *);
 429 int  nfs_show_options(struct seq_file *, struct dentry *);
 430 int  nfs_show_devname(struct seq_file *, struct dentry *);
 431 int  nfs_show_path(struct seq_file *, struct dentry *);
 432 int  nfs_show_stats(struct seq_file *, struct dentry *);
 433 int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 434
 435 /* write.c */
 436 extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
 437                         struct inode *inode, int ioflags, bool force_mds,
 438                         const struct nfs_pgio_completion_ops *compl_ops);
 439 extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
 440 extern void nfs_commit_free(struct nfs_commit_data *p);
 441 extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
 442 extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
 443 extern int nfs_initiate_commit(struct rpc_clnt *clnt,
 444                                struct nfs_commit_data *data,
 445                                const struct nfs_rpc_ops *nfs_ops,
 446                                const struct rpc_call_ops *call_ops,
 447                                int how, int flags);
 448 extern void nfs_init_commit(struct nfs_commit_data *data,
 449                             struct list_head *head,
 450                             struct pnfs_layout_segment *lseg,
 451                             struct nfs_commit_info *cinfo);
 452 int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
 453                          struct nfs_commit_info *cinfo, int max);
 454 unsigned long nfs_reqs_to_commit(struct nfs_commit_info *);
 455 int nfs_scan_commit(struct inode *inode, struct list_head *dst,
 456                     struct nfs_commit_info *cinfo);
 457 void nfs_mark_request_commit(struct nfs_page *req,
 458                              struct pnfs_layout_segment *lseg,
 459                              struct nfs_commit_info *cinfo,
 460                              u32 ds_commit_idx);
 461 int nfs_write_need_commit(struct nfs_pgio_header *);
 462 int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
 463                             int how, struct nfs_commit_info *cinfo);
 464 void nfs_retry_commit(struct list_head *page_list,
 465                       struct pnfs_layout_segment *lseg,
 466                       struct nfs_commit_info *cinfo,
 467                       u32 ds_commit_idx);
 468 void nfs_commitdata_release(struct nfs_commit_data *data);
 469 void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
 470                                  struct nfs_commit_info *cinfo);
 471 void nfs_request_remove_commit_list(struct nfs_page *req,
 472                                     struct nfs_commit_info *cinfo);
 473 void nfs_init_cinfo(struct nfs_commit_info *cinfo,
 474                     struct inode *inode,
 475                     struct nfs_direct_req *dreq);
 476 int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
 477 bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx);
 478 void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio);
 479
 480 #ifdef CONFIG_MIGRATION
 481 extern int nfs_migrate_page(struct address_space *,
 482                 struct page *, struct page *, enum migrate_mode);
 483 #else
 484 #define nfs_migrate_page NULL
 485 #endif
 486
 487 /* unlink.c */
 488 extern struct rpc_task *
 489 nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
 490                  struct dentry *old_dentry, struct dentry *new_dentry,
 491                  void (*complete)(struct rpc_task *, struct nfs_renamedata *));
 492 extern int nfs_sillyrename(struct inode *dir, struct dentry *dentry);
 493
 494 /* direct.c */
 495 void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
 496                               struct nfs_direct_req *dreq);
 497 static inline void nfs_inode_dio_wait(struct inode *inode)
 498 {
 499         inode_dio_wait(inode);
 500 }
 501 extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
 502 extern void nfs_direct_set_resched_writes(struct nfs_direct_req *dreq);
 503
 504 /* nfs4proc.c */
 505 extern void __nfs4_read_done_cb(struct nfs_pgio_header *);
 506 extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
 507                             const struct rpc_timeout *timeparms,
 508                             const char *ip_addr);
 509 extern int nfs40_walk_client_list(struct nfs_client *clp,
 510                                 struct nfs_client **result,
 511                                 struct rpc_cred *cred);
 512 extern int nfs41_walk_client_list(struct nfs_client *clp,
 513                                 struct nfs_client **result,
 514                                 struct rpc_cred *cred);
 515
 516 static inline struct inode *nfs_igrab_and_active(struct inode *inode)
 517 {
 518         inode = igrab(inode);
 519         if (inode != NULL && !nfs_sb_active(inode->i_sb)) {
 520                 iput(inode);
 521                 inode = NULL;
 522         }
 523         return inode;
 524 }
 525
 526 static inline void nfs_iput_and_deactive(struct inode *inode)
 527 {
 528         if (inode != NULL) {
 529                 struct super_block *sb = inode->i_sb;
 530
 531                 iput(inode);
 532                 nfs_sb_deactive(sb);
 533         }
 534 }
 535
 536 /*
 537  * Determine the device name as a string
 538  */
 539 static inline char *nfs_devname(struct dentry *dentry,
 540                                 char *buffer, ssize_t buflen)
 541 {
 542         char *dummy;
 543         return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
 544 }
 545
 546 /*
 547  * Determine the actual block size (and log2 thereof)
 548  */
 549 static inline
 550 unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
 551 {
 552         /* make sure blocksize is a power of two */
 553         if ((bsize & (bsize - 1)) || nrbitsp) {
 554                 unsigned char   nrbits;
 555
 556                 for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
 557                         ;
 558                 bsize = 1 << nrbits;
 559                 if (nrbitsp)
 560                         *nrbitsp = nrbits;
 561         }
 562
 563         return bsize;
 564 }
 565
 566 /*
 567  * Calculate the number of 512byte blocks used.
 568  */
 569 static inline blkcnt_t nfs_calc_block_size(u64 tsize)
 570 {
 571         blkcnt_t used = (tsize + 511) >> 9;
 572         return (used > ULONG_MAX) ? ULONG_MAX : used;
 573 }
 574
 575 /*
 576  * Compute and set NFS server blocksize
 577  */
 578 static inline
 579 unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
 580 {
 581         if (bsize < NFS_MIN_FILE_IO_SIZE)
 582                 bsize = NFS_DEF_FILE_IO_SIZE;
 583         else if (bsize >= NFS_MAX_FILE_IO_SIZE)
 584                 bsize = NFS_MAX_FILE_IO_SIZE;
 585
 586         return nfs_block_bits(bsize, nrbitsp);
 587 }
 588
 589 /*
 590  * Determine the maximum file size for a superblock
 591  */
 592 static inline
 593 void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
 594 {
 595         sb->s_maxbytes = (loff_t)maxfilesize;
 596         if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
 597                 sb->s_maxbytes = MAX_LFS_FILESIZE;
 598 }
 599
 600 /*
 601  * Record the page as unstable and mark its inode as dirty.
 602  */
 603 static inline
 604 void nfs_mark_page_unstable(struct page *page)
 605 {
 606         struct inode *inode = page_file_mapping(page)->host;
 607
 608         inc_zone_page_state(page, NR_UNSTABLE_NFS);
 609         inc_bdi_stat(inode_to_bdi(inode), BDI_RECLAIMABLE);
 610          __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
 611 }
 612
 613 /*
 614  * Determine the number of bytes of data the page contains
 615  */
 616 static inline
 617 unsigned int nfs_page_length(struct page *page)
 618 {
 619         loff_t i_size = i_size_read(page_file_mapping(page)->host);
 620
 621         if (i_size > 0) {
 622                 pgoff_t page_index = page_file_index(page);
 623                 pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
 624                 if (page_index < end_index)
 625                         return PAGE_CACHE_SIZE;
 626                 if (page_index == end_index)
 627                         return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
 628         }
 629         return 0;
 630 }
 631
 632 /*
 633  * Convert a umode to a dirent->d_type
 634  */
 635 static inline
 636 unsigned char nfs_umode_to_dtype(umode_t mode)
 637 {
 638         return (mode >> 12) & 15;
 639 }
 640
 641 /*
 642  * Determine the number of pages in an array of length 'len' and
 643  * with a base offset of 'base'
 644  */
 645 static inline
 646 unsigned int nfs_page_array_len(unsigned int base, size_t len)
 647 {
 648         return ((unsigned long)len + (unsigned long)base +
 649                 PAGE_SIZE - 1) >> PAGE_SHIFT;
 650 }
 651
 652 /*
 653  * Convert a struct timespec into a 64-bit change attribute
 654  *
 655  * This does approximately the same thing as timespec_to_ns(),
 656  * but for calculation efficiency, we multiply the seconds by
 657  * 1024*1024*1024.
 658  */
 659 static inline
 660 u64 nfs_timespec_to_change_attr(const struct timespec *ts)
 661 {
 662         return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
 663 }
 664
 665 #ifdef CONFIG_CRC32
 666 /**
 667  * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
 668  * @fh - pointer to filehandle
 669  *
 670  * returns a crc32 hash for the filehandle that is compatible with
 671  * the one displayed by "wireshark".
 672  */
 673 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
 674 {
 675         return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
 676 }
 677 #else
 678 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
 679 {
 680         return 0;
 681 }
 682 #endif