1 /* 2 * linux/fs/nfs/nfs4_fs.h 3 * 4 * Copyright (C) 2005 Trond Myklebust 5 * 6 * NFSv4-specific filesystem definitions and declarations 7 */ 8 9 #ifndef __LINUX_FS_NFS_NFS4_FS_H 10 #define __LINUX_FS_NFS_NFS4_FS_H 11 12 #if defined(CONFIG_NFS_V4_2) 13 #define NFS4_MAX_MINOR_VERSION 2 14 #elif defined(CONFIG_NFS_V4_1) 15 #define NFS4_MAX_MINOR_VERSION 1 16 #else 17 #define NFS4_MAX_MINOR_VERSION 0 18 #endif 19 20 #if IS_ENABLED(CONFIG_NFS_V4) 21 22 #define NFS4_MAX_LOOP_ON_RECOVER (10) 23 24 #include <linux/seqlock.h> 25 26 struct idmap; 27 28 enum nfs4_client_state { 29 NFS4CLNT_MANAGER_RUNNING = 0, 30 NFS4CLNT_CHECK_LEASE, 31 NFS4CLNT_LEASE_EXPIRED, 32 NFS4CLNT_RECLAIM_REBOOT, 33 NFS4CLNT_RECLAIM_NOGRACE, 34 NFS4CLNT_DELEGRETURN, 35 NFS4CLNT_SESSION_RESET, 36 NFS4CLNT_LEASE_CONFIRM, 37 NFS4CLNT_SERVER_SCOPE_MISMATCH, 38 NFS4CLNT_PURGE_STATE, 39 NFS4CLNT_BIND_CONN_TO_SESSION, 40 NFS4CLNT_MOVED, 41 NFS4CLNT_LEASE_MOVED, 42 }; 43 44 #define NFS4_RENEW_TIMEOUT 0x01 45 #define NFS4_RENEW_DELEGATION_CB 0x02 46 47 struct nfs_seqid_counter; 48 struct nfs4_minor_version_ops { 49 u32 minor_version; 50 unsigned init_caps; 51 52 int (*init_client)(struct nfs_client *); 53 void (*shutdown_client)(struct nfs_client *); 54 bool (*match_stateid)(const nfs4_stateid *, 55 const nfs4_stateid *); 56 int (*find_root_sec)(struct nfs_server *, struct nfs_fh *, 57 struct nfs_fsinfo *); 58 void (*free_lock_state)(struct nfs_server *, 59 struct nfs4_lock_state *); 60 struct nfs_seqid * 61 (*alloc_seqid)(struct nfs_seqid_counter *, gfp_t); 62 const struct rpc_call_ops *call_sync_ops; 63 const struct nfs4_state_recovery_ops *reboot_recovery_ops; 64 const struct nfs4_state_recovery_ops *nograce_recovery_ops; 65 const struct nfs4_state_maintenance_ops *state_renewal_ops; 66 const struct nfs4_mig_recovery_ops *mig_recovery_ops; 67 }; 68 69 #define NFS_SEQID_CONFIRMED 1 70 struct nfs_seqid_counter { 71 ktime_t create_time; 72 int owner_id; 73 int flags; 74 u32 counter; 75 spinlock_t lock; /* Protects the list */ 76 struct list_head list; /* Defines sequence of RPC calls */ 77 struct rpc_wait_queue wait; /* RPC call delay queue */ 78 }; 79 80 struct nfs_seqid { 81 struct nfs_seqid_counter *sequence; 82 struct list_head list; 83 struct rpc_task *task; 84 }; 85 86 static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status) 87 { 88 if (seqid_mutating_err(-status)) 89 seqid->flags |= NFS_SEQID_CONFIRMED; 90 } 91 92 /* 93 * NFS4 state_owners and lock_owners are simply labels for ordered 94 * sequences of RPC calls. Their sole purpose is to provide once-only 95 * semantics by allowing the server to identify replayed requests. 96 */ 97 struct nfs4_state_owner { 98 struct nfs_server *so_server; 99 struct list_head so_lru; 100 unsigned long so_expires; 101 struct rb_node so_server_node; 102 103 struct rpc_cred *so_cred; /* Associated cred */ 104 105 spinlock_t so_lock; 106 atomic_t so_count; 107 unsigned long so_flags; 108 struct list_head so_states; 109 struct nfs_seqid_counter so_seqid; 110 seqcount_t so_reclaim_seqcount; 111 struct mutex so_delegreturn_mutex; 112 }; 113 114 enum { 115 NFS_OWNER_RECLAIM_REBOOT, 116 NFS_OWNER_RECLAIM_NOGRACE 117 }; 118 119 #define NFS_LOCK_NEW 0 120 #define NFS_LOCK_RECLAIM 1 121 #define NFS_LOCK_EXPIRED 2 122 123 /* 124 * struct nfs4_state maintains the client-side state for a given 125 * (state_owner,inode) tuple (OPEN) or state_owner (LOCK). 126 * 127 * OPEN: 128 * In order to know when to OPEN_DOWNGRADE or CLOSE the state on the server, 129 * we need to know how many files are open for reading or writing on a 130 * given inode. This information too is stored here. 131 * 132 * LOCK: one nfs4_state (LOCK) to hold the lock stateid nfs4_state(OPEN) 133 */ 134 135 struct nfs4_lock_state { 136 struct list_head ls_locks; /* Other lock stateids */ 137 struct nfs4_state * ls_state; /* Pointer to open state */ 138 #define NFS_LOCK_INITIALIZED 0 139 #define NFS_LOCK_LOST 1 140 unsigned long ls_flags; 141 struct nfs_seqid_counter ls_seqid; 142 nfs4_stateid ls_stateid; 143 atomic_t ls_count; 144 fl_owner_t ls_owner; 145 }; 146 147 /* bits for nfs4_state->flags */ 148 enum { 149 LK_STATE_IN_USE, 150 NFS_DELEGATED_STATE, /* Current stateid is delegation */ 151 NFS_OPEN_STATE, /* OPEN stateid is set */ 152 NFS_O_RDONLY_STATE, /* OPEN stateid has read-only state */ 153 NFS_O_WRONLY_STATE, /* OPEN stateid has write-only state */ 154 NFS_O_RDWR_STATE, /* OPEN stateid has read/write state */ 155 NFS_STATE_RECLAIM_REBOOT, /* OPEN stateid server rebooted */ 156 NFS_STATE_RECLAIM_NOGRACE, /* OPEN stateid needs to recover state */ 157 NFS_STATE_POSIX_LOCKS, /* Posix locks are supported */ 158 NFS_STATE_RECOVERY_FAILED, /* OPEN stateid state recovery failed */ 159 }; 160 161 struct nfs4_state { 162 struct list_head open_states; /* List of states for the same state_owner */ 163 struct list_head inode_states; /* List of states for the same inode */ 164 struct list_head lock_states; /* List of subservient lock stateids */ 165 166 struct nfs4_state_owner *owner; /* Pointer to the open owner */ 167 struct inode *inode; /* Pointer to the inode */ 168 169 unsigned long flags; /* Do we hold any locks? */ 170 spinlock_t state_lock; /* Protects the lock_states list */ 171 172 seqlock_t seqlock; /* Protects the stateid/open_stateid */ 173 nfs4_stateid stateid; /* Current stateid: may be delegation */ 174 nfs4_stateid open_stateid; /* OPEN stateid */ 175 176 /* The following 3 fields are protected by owner->so_lock */ 177 unsigned int n_rdonly; /* Number of read-only references */ 178 unsigned int n_wronly; /* Number of write-only references */ 179 unsigned int n_rdwr; /* Number of read/write references */ 180 fmode_t state; /* State on the server (R,W, or RW) */ 181 atomic_t count; 182 }; 183 184 185 struct nfs4_exception { 186 struct nfs4_state *state; 187 struct inode *inode; 188 long timeout; 189 unsigned char delay : 1, 190 recovering : 1, 191 retry : 1; 192 }; 193 194 struct nfs4_state_recovery_ops { 195 int owner_flag_bit; 196 int state_flag_bit; 197 int (*recover_open)(struct nfs4_state_owner *, struct nfs4_state *); 198 int (*recover_lock)(struct nfs4_state *, struct file_lock *); 199 int (*establish_clid)(struct nfs_client *, struct rpc_cred *); 200 int (*reclaim_complete)(struct nfs_client *, struct rpc_cred *); 201 int (*detect_trunking)(struct nfs_client *, struct nfs_client **, 202 struct rpc_cred *); 203 }; 204 205 struct nfs4_state_maintenance_ops { 206 int (*sched_state_renewal)(struct nfs_client *, struct rpc_cred *, unsigned); 207 struct rpc_cred * (*get_state_renewal_cred_locked)(struct nfs_client *); 208 int (*renew_lease)(struct nfs_client *, struct rpc_cred *); 209 }; 210 211 struct nfs4_mig_recovery_ops { 212 int (*get_locations)(struct inode *, struct nfs4_fs_locations *, 213 struct page *, struct rpc_cred *); 214 int (*fsid_present)(struct inode *, struct rpc_cred *); 215 }; 216 217 extern const struct dentry_operations nfs4_dentry_operations; 218 219 /* dir.c */ 220 int nfs_atomic_open(struct inode *, struct dentry *, struct file *, 221 unsigned, umode_t, int *); 222 223 /* super.c */ 224 extern struct file_system_type nfs4_fs_type; 225 226 /* nfs4namespace.c */ 227 struct rpc_clnt *nfs4_negotiate_security(struct rpc_clnt *, struct inode *, struct qstr *); 228 struct vfsmount *nfs4_submount(struct nfs_server *, struct dentry *, 229 struct nfs_fh *, struct nfs_fattr *); 230 int nfs4_replace_transport(struct nfs_server *server, 231 const struct nfs4_fs_locations *locations); 232 233 /* nfs4proc.c */ 234 extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception *); 235 extern int nfs4_call_sync(struct rpc_clnt *, struct nfs_server *, 236 struct rpc_message *, struct nfs4_sequence_args *, 237 struct nfs4_sequence_res *, int); 238 extern void nfs4_init_sequence(struct nfs4_sequence_args *, struct nfs4_sequence_res *, int); 239 extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, struct rpc_cred *, struct nfs4_setclientid_res *); 240 extern int nfs4_proc_setclientid_confirm(struct nfs_client *, struct nfs4_setclientid_res *arg, struct rpc_cred *); 241 extern int nfs4_proc_get_rootfh(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *, bool); 242 extern int nfs4_proc_bind_conn_to_session(struct nfs_client *, struct rpc_cred *cred); 243 extern int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred); 244 extern int nfs4_destroy_clientid(struct nfs_client *clp); 245 extern int nfs4_init_clientid(struct nfs_client *, struct rpc_cred *); 246 extern int nfs41_init_clientid(struct nfs_client *, struct rpc_cred *); 247 extern int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait); 248 extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle); 249 extern int nfs4_proc_fs_locations(struct rpc_clnt *, struct inode *, const struct qstr *, 250 struct nfs4_fs_locations *, struct page *); 251 extern int nfs4_proc_get_locations(struct inode *, struct nfs4_fs_locations *, 252 struct page *page, struct rpc_cred *); 253 extern int nfs4_proc_fsid_present(struct inode *, struct rpc_cred *); 254 extern struct rpc_clnt *nfs4_proc_lookup_mountpoint(struct inode *, struct qstr *, 255 struct nfs_fh *, struct nfs_fattr *); 256 extern int nfs4_proc_secinfo(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *); 257 extern const struct xattr_handler *nfs4_xattr_handlers[]; 258 extern int nfs4_set_rw_stateid(nfs4_stateid *stateid, 259 const struct nfs_open_context *ctx, 260 const struct nfs_lock_context *l_ctx, 261 fmode_t fmode); 262 263 #if defined(CONFIG_NFS_V4_1) 264 static inline struct nfs4_session *nfs4_get_session(const struct nfs_server *server) 265 { 266 return server->nfs_client->cl_session; 267 } 268 269 extern int nfs41_setup_sequence(struct nfs4_session *session, 270 struct nfs4_sequence_args *args, struct nfs4_sequence_res *res, 271 struct rpc_task *task); 272 extern int nfs41_sequence_done(struct rpc_task *, struct nfs4_sequence_res *); 273 extern int nfs4_proc_create_session(struct nfs_client *, struct rpc_cred *); 274 extern int nfs4_proc_destroy_session(struct nfs4_session *, struct rpc_cred *); 275 extern int nfs4_proc_get_lease_time(struct nfs_client *clp, 276 struct nfs_fsinfo *fsinfo); 277 extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data, 278 bool sync); 279 280 static inline bool 281 is_ds_only_client(struct nfs_client *clp) 282 { 283 return (clp->cl_exchange_flags & EXCHGID4_FLAG_MASK_PNFS) == 284 EXCHGID4_FLAG_USE_PNFS_DS; 285 } 286 287 static inline bool 288 is_ds_client(struct nfs_client *clp) 289 { 290 return clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_DS; 291 } 292 293 static inline bool 294 _nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode, 295 struct rpc_clnt **clntp, struct rpc_message *msg) 296 { 297 struct rpc_cred *newcred = NULL; 298 rpc_authflavor_t flavor; 299 300 if (test_bit(sp4_mode, &clp->cl_sp4_flags)) { 301 spin_lock(&clp->cl_lock); 302 if (clp->cl_machine_cred != NULL) 303 /* don't call get_rpccred on the machine cred - 304 * a reference will be held for life of clp */ 305 newcred = clp->cl_machine_cred; 306 spin_unlock(&clp->cl_lock); 307 msg->rpc_cred = newcred; 308 309 flavor = clp->cl_rpcclient->cl_auth->au_flavor; 310 WARN_ON_ONCE(flavor != RPC_AUTH_GSS_KRB5I && 311 flavor != RPC_AUTH_GSS_KRB5P); 312 *clntp = clp->cl_rpcclient; 313 314 return true; 315 } 316 return false; 317 } 318 319 /* 320 * Function responsible for determining if an rpc_message should use the 321 * machine cred under SP4_MACH_CRED and if so switching the credential and 322 * authflavor (using the nfs_client's rpc_clnt which will be krb5i/p). 323 * Should be called before rpc_call_sync/rpc_call_async. 324 */ 325 static inline void 326 nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode, 327 struct rpc_clnt **clntp, struct rpc_message *msg) 328 { 329 _nfs4_state_protect(clp, sp4_mode, clntp, msg); 330 } 331 332 /* 333 * Special wrapper to nfs4_state_protect for write. 334 * If WRITE can use machine cred but COMMIT cannot, make sure all writes 335 * that use machine cred use NFS_FILE_SYNC. 336 */ 337 static inline void 338 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp, 339 struct rpc_message *msg, struct nfs_pgio_header *hdr) 340 { 341 if (_nfs4_state_protect(clp, NFS_SP4_MACH_CRED_WRITE, clntp, msg) && 342 !test_bit(NFS_SP4_MACH_CRED_COMMIT, &clp->cl_sp4_flags)) 343 hdr->args.stable = NFS_FILE_SYNC; 344 } 345 #else /* CONFIG_NFS_v4_1 */ 346 static inline struct nfs4_session *nfs4_get_session(const struct nfs_server *server) 347 { 348 return NULL; 349 } 350 351 static inline bool 352 is_ds_only_client(struct nfs_client *clp) 353 { 354 return false; 355 } 356 357 static inline bool 358 is_ds_client(struct nfs_client *clp) 359 { 360 return false; 361 } 362 363 static inline void 364 nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_flags, 365 struct rpc_clnt **clntp, struct rpc_message *msg) 366 { 367 } 368 369 static inline void 370 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp, 371 struct rpc_message *msg, struct nfs_pgio_header *hdr) 372 { 373 } 374 #endif /* CONFIG_NFS_V4_1 */ 375 376 extern const struct nfs4_minor_version_ops *nfs_v4_minor_ops[]; 377 378 extern const u32 nfs4_fattr_bitmap[3]; 379 extern const u32 nfs4_statfs_bitmap[3]; 380 extern const u32 nfs4_pathconf_bitmap[3]; 381 extern const u32 nfs4_fsinfo_bitmap[3]; 382 extern const u32 nfs4_fs_locations_bitmap[3]; 383 384 void nfs40_shutdown_client(struct nfs_client *); 385 void nfs41_shutdown_client(struct nfs_client *); 386 int nfs40_init_client(struct nfs_client *); 387 int nfs41_init_client(struct nfs_client *); 388 void nfs4_free_client(struct nfs_client *); 389 390 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *); 391 392 /* nfs4renewd.c */ 393 extern void nfs4_schedule_state_renewal(struct nfs_client *); 394 extern void nfs4_renewd_prepare_shutdown(struct nfs_server *); 395 extern void nfs4_kill_renewd(struct nfs_client *); 396 extern void nfs4_renew_state(struct work_struct *); 397 398 /* nfs4state.c */ 399 struct rpc_cred *nfs4_get_clid_cred(struct nfs_client *clp); 400 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp); 401 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp); 402 int nfs4_discover_server_trunking(struct nfs_client *clp, 403 struct nfs_client **); 404 int nfs40_discover_server_trunking(struct nfs_client *clp, 405 struct nfs_client **, struct rpc_cred *); 406 #if defined(CONFIG_NFS_V4_1) 407 int nfs41_discover_server_trunking(struct nfs_client *clp, 408 struct nfs_client **, struct rpc_cred *); 409 extern void nfs4_schedule_session_recovery(struct nfs4_session *, int); 410 extern void nfs41_notify_server(struct nfs_client *); 411 #else 412 static inline void nfs4_schedule_session_recovery(struct nfs4_session *session, int err) 413 { 414 } 415 #endif /* CONFIG_NFS_V4_1 */ 416 417 extern struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *, struct rpc_cred *, gfp_t); 418 extern void nfs4_put_state_owner(struct nfs4_state_owner *); 419 extern void nfs4_purge_state_owners(struct nfs_server *); 420 extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *); 421 extern void nfs4_put_open_state(struct nfs4_state *); 422 extern void nfs4_close_state(struct nfs4_state *, fmode_t); 423 extern void nfs4_close_sync(struct nfs4_state *, fmode_t); 424 extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t); 425 extern void nfs_inode_find_state_and_recover(struct inode *inode, 426 const nfs4_stateid *stateid); 427 extern int nfs4_state_mark_reclaim_nograce(struct nfs_client *, struct nfs4_state *); 428 extern void nfs4_schedule_lease_recovery(struct nfs_client *); 429 extern int nfs4_wait_clnt_recover(struct nfs_client *clp); 430 extern int nfs4_client_recover_expired_lease(struct nfs_client *clp); 431 extern void nfs4_schedule_state_manager(struct nfs_client *); 432 extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp); 433 extern int nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *); 434 extern int nfs4_schedule_migration_recovery(const struct nfs_server *); 435 extern void nfs4_schedule_lease_moved_recovery(struct nfs_client *); 436 extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags); 437 extern void nfs41_handle_server_scope(struct nfs_client *, 438 struct nfs41_server_scope **); 439 extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp); 440 extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl); 441 extern int nfs4_select_rw_stateid(nfs4_stateid *, struct nfs4_state *, 442 fmode_t, const struct nfs_lockowner *); 443 444 extern struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask); 445 extern int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task); 446 extern void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid); 447 extern void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid); 448 extern void nfs_release_seqid(struct nfs_seqid *seqid); 449 extern void nfs_free_seqid(struct nfs_seqid *seqid); 450 extern int nfs40_setup_sequence(struct nfs4_slot_table *tbl, 451 struct nfs4_sequence_args *args, 452 struct nfs4_sequence_res *res, 453 struct rpc_task *task); 454 extern int nfs4_sequence_done(struct rpc_task *task, 455 struct nfs4_sequence_res *res); 456 457 extern void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp); 458 459 extern const nfs4_stateid zero_stateid; 460 461 /* nfs4super.c */ 462 struct nfs_mount_info; 463 extern struct nfs_subversion nfs_v4; 464 struct dentry *nfs4_try_mount(int, const char *, struct nfs_mount_info *, struct nfs_subversion *); 465 extern bool nfs4_disable_idmapping; 466 extern unsigned short max_session_slots; 467 extern unsigned short send_implementation_id; 468 extern bool recover_lost_locks; 469 470 #define NFS4_CLIENT_ID_UNIQ_LEN (64) 471 extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN]; 472 473 /* nfs4sysctl.c */ 474 #ifdef CONFIG_SYSCTL 475 int nfs4_register_sysctl(void); 476 void nfs4_unregister_sysctl(void); 477 #else 478 static inline int nfs4_register_sysctl(void) 479 { 480 return 0; 481 } 482 483 static inline void nfs4_unregister_sysctl(void) 484 { 485 } 486 #endif 487 488 /* nfs4xdr.c */ 489 extern struct rpc_procinfo nfs4_procedures[]; 490 491 struct nfs4_mount_data; 492 493 /* callback_xdr.c */ 494 extern struct svc_version nfs4_callback_version1; 495 extern struct svc_version nfs4_callback_version4; 496 497 static inline void nfs4_stateid_copy(nfs4_stateid *dst, const nfs4_stateid *src) 498 { 499 memcpy(dst, src, sizeof(*dst)); 500 } 501 502 static inline bool nfs4_stateid_match(const nfs4_stateid *dst, const nfs4_stateid *src) 503 { 504 return memcmp(dst, src, sizeof(*dst)) == 0; 505 } 506 507 static inline bool nfs4_stateid_match_other(const nfs4_stateid *dst, const nfs4_stateid *src) 508 { 509 return memcmp(dst->other, src->other, NFS4_STATEID_OTHER_SIZE) == 0; 510 } 511 512 static inline bool nfs4_stateid_is_newer(const nfs4_stateid *s1, const nfs4_stateid *s2) 513 { 514 return (s32)(be32_to_cpu(s1->seqid) - be32_to_cpu(s2->seqid)) > 0; 515 } 516 517 static inline bool nfs4_valid_open_stateid(const struct nfs4_state *state) 518 { 519 return test_bit(NFS_STATE_RECOVERY_FAILED, &state->flags) == 0; 520 } 521 522 #else 523 524 #define nfs4_close_state(a, b) do { } while (0) 525 #define nfs4_close_sync(a, b) do { } while (0) 526 #define nfs4_state_protect(a, b, c, d) do { } while (0) 527 #define nfs4_state_protect_write(a, b, c, d) do { } while (0) 528 529 #endif /* CONFIG_NFS_V4 */ 530 #endif /* __LINUX_FS_NFS_NFS4_FS.H */ 531