1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * linux/include/linux/nfs_fs.h 4 * 5 * Copyright (C) 1992 Rick Sladkey 6 * 7 * OS-specific nfs filesystem definitions and declarations 8 */ 9 #ifndef _LINUX_NFS_FS_H 10 #define _LINUX_NFS_FS_H 11 12 #include <uapi/linux/nfs_fs.h> 13 14 15 /* 16 * Enable dprintk() debugging support for nfs client. 17 */ 18 #ifdef CONFIG_NFS_DEBUG 19 # define NFS_DEBUG 20 #endif 21 22 #include <linux/in.h> 23 #include <linux/mm.h> 24 #include <linux/pagemap.h> 25 #include <linux/rbtree.h> 26 #include <linux/refcount.h> 27 #include <linux/rwsem.h> 28 #include <linux/wait.h> 29 30 #include <linux/sunrpc/debug.h> 31 #include <linux/sunrpc/auth.h> 32 #include <linux/sunrpc/clnt.h> 33 34 #include <linux/nfs.h> 35 #include <linux/nfs2.h> 36 #include <linux/nfs3.h> 37 #include <linux/nfs4.h> 38 #include <linux/nfs_xdr.h> 39 #include <linux/nfs_fs_sb.h> 40 41 #include <linux/mempool.h> 42 43 /* 44 * These are the default for number of transports to different server IPs 45 */ 46 #define NFS_MAX_TRANSPORTS 16 47 48 /* 49 * Size of the NFS directory verifier 50 */ 51 #define NFS_DIR_VERIFIER_SIZE 2 52 53 /* 54 * NFSv3/v4 Access mode cache entry 55 */ 56 struct nfs_access_entry { 57 struct rb_node rb_node; 58 struct list_head lru; 59 kuid_t fsuid; 60 kgid_t fsgid; 61 struct group_info *group_info; 62 u64 timestamp; 63 __u32 mask; 64 struct rcu_head rcu_head; 65 }; 66 67 struct nfs_lock_context { 68 refcount_t count; 69 struct list_head list; 70 struct nfs_open_context *open_context; 71 fl_owner_t lockowner; 72 atomic_t io_count; 73 struct rcu_head rcu_head; 74 }; 75 76 struct nfs4_state; 77 struct nfs_open_context { 78 struct nfs_lock_context lock_context; 79 fl_owner_t flock_owner; 80 struct dentry *dentry; 81 const struct cred *cred; 82 struct rpc_cred __rcu *ll_cred; /* low-level cred - use to check for expiry */ 83 struct nfs4_state *state; 84 fmode_t mode; 85 86 unsigned long flags; 87 #define NFS_CONTEXT_BAD (2) 88 #define NFS_CONTEXT_UNLOCK (3) 89 #define NFS_CONTEXT_FILE_OPEN (4) 90 int error; 91 92 struct list_head list; 93 struct nfs4_threshold *mdsthreshold; 94 struct rcu_head rcu_head; 95 }; 96 97 struct nfs_open_dir_context { 98 struct list_head list; 99 atomic_t cache_hits; 100 atomic_t cache_misses; 101 unsigned long attr_gencount; 102 __be32 verf[NFS_DIR_VERIFIER_SIZE]; 103 __u64 dir_cookie; 104 __u64 last_cookie; 105 pgoff_t page_index; 106 unsigned int dtsize; 107 bool force_clear; 108 bool eof; 109 struct rcu_head rcu_head; 110 }; 111 112 /* 113 * NFSv4 delegation 114 */ 115 struct nfs_delegation; 116 117 struct posix_acl; 118 119 struct nfs4_xattr_cache; 120 121 /* 122 * nfs fs inode data in memory 123 */ 124 struct nfs_inode { 125 /* 126 * The 64bit 'inode number' 127 */ 128 __u64 fileid; 129 130 /* 131 * NFS file handle 132 */ 133 struct nfs_fh fh; 134 135 /* 136 * Various flags 137 */ 138 unsigned long flags; /* atomic bit ops */ 139 unsigned long cache_validity; /* bit mask */ 140 141 /* 142 * read_cache_jiffies is when we started read-caching this inode. 143 * attrtimeo is for how long the cached information is assumed 144 * to be valid. A successful attribute revalidation doubles 145 * attrtimeo (up to acregmax/acdirmax), a failure resets it to 146 * acregmin/acdirmin. 147 * 148 * We need to revalidate the cached attrs for this inode if 149 * 150 * jiffies - read_cache_jiffies >= attrtimeo 151 * 152 * Please note the comparison is greater than or equal 153 * so that zero timeout values can be specified. 154 */ 155 unsigned long read_cache_jiffies; 156 unsigned long attrtimeo; 157 unsigned long attrtimeo_timestamp; 158 159 unsigned long attr_gencount; 160 161 struct rb_root access_cache; 162 struct list_head access_cache_entry_lru; 163 struct list_head access_cache_inode_lru; 164 165 union { 166 /* Directory */ 167 struct { 168 /* "Generation counter" for the attribute cache. 169 * This is bumped whenever we update the metadata 170 * on the server. 171 */ 172 unsigned long cache_change_attribute; 173 /* 174 * This is the cookie verifier used for NFSv3 readdir 175 * operations 176 */ 177 __be32 cookieverf[NFS_DIR_VERIFIER_SIZE]; 178 /* Readers: in-flight sillydelete RPC calls */ 179 /* Writers: rmdir */ 180 struct rw_semaphore rmdir_sem; 181 }; 182 /* Regular file */ 183 struct { 184 atomic_long_t nrequests; 185 atomic_long_t redirtied_pages; 186 struct nfs_mds_commit_info commit_info; 187 struct mutex commit_mutex; 188 }; 189 }; 190 191 /* Open contexts for shared mmap writes */ 192 struct list_head open_files; 193 194 #if IS_ENABLED(CONFIG_NFS_V4) 195 struct nfs4_cached_acl *nfs4_acl; 196 /* NFSv4 state */ 197 struct list_head open_states; 198 struct nfs_delegation __rcu *delegation; 199 struct rw_semaphore rwsem; 200 201 /* pNFS layout information */ 202 struct pnfs_layout_hdr *layout; 203 #endif /* CONFIG_NFS_V4*/ 204 /* how many bytes have been written/read and how many bytes queued up */ 205 __u64 write_io; 206 __u64 read_io; 207 #ifdef CONFIG_NFS_FSCACHE 208 struct fscache_cookie *fscache; 209 #endif 210 struct inode vfs_inode; 211 212 #ifdef CONFIG_NFS_V4_2 213 struct nfs4_xattr_cache *xattr_cache; 214 #endif 215 }; 216 217 struct nfs4_copy_state { 218 struct list_head copies; 219 struct list_head src_copies; 220 nfs4_stateid stateid; 221 struct completion completion; 222 uint64_t count; 223 struct nfs_writeverf verf; 224 int error; 225 int flags; 226 struct nfs4_state *parent_src_state; 227 struct nfs4_state *parent_dst_state; 228 }; 229 230 /* 231 * Access bit flags 232 */ 233 #define NFS_ACCESS_READ 0x0001 234 #define NFS_ACCESS_LOOKUP 0x0002 235 #define NFS_ACCESS_MODIFY 0x0004 236 #define NFS_ACCESS_EXTEND 0x0008 237 #define NFS_ACCESS_DELETE 0x0010 238 #define NFS_ACCESS_EXECUTE 0x0020 239 #define NFS_ACCESS_XAREAD 0x0040 240 #define NFS_ACCESS_XAWRITE 0x0080 241 #define NFS_ACCESS_XALIST 0x0100 242 243 /* 244 * Cache validity bit flags 245 */ 246 #define NFS_INO_INVALID_DATA BIT(1) /* cached data is invalid */ 247 #define NFS_INO_INVALID_ATIME BIT(2) /* cached atime is invalid */ 248 #define NFS_INO_INVALID_ACCESS BIT(3) /* cached access cred invalid */ 249 #define NFS_INO_INVALID_ACL BIT(4) /* cached acls are invalid */ 250 #define NFS_INO_REVAL_FORCED BIT(6) /* force revalidation ignoring a delegation */ 251 #define NFS_INO_INVALID_LABEL BIT(7) /* cached label is invalid */ 252 #define NFS_INO_INVALID_CHANGE BIT(8) /* cached change is invalid */ 253 #define NFS_INO_INVALID_CTIME BIT(9) /* cached ctime is invalid */ 254 #define NFS_INO_INVALID_MTIME BIT(10) /* cached mtime is invalid */ 255 #define NFS_INO_INVALID_SIZE BIT(11) /* cached size is invalid */ 256 #define NFS_INO_INVALID_OTHER BIT(12) /* other attrs are invalid */ 257 #define NFS_INO_DATA_INVAL_DEFER \ 258 BIT(13) /* Deferred cache invalidation */ 259 #define NFS_INO_INVALID_BLOCKS BIT(14) /* cached blocks are invalid */ 260 #define NFS_INO_INVALID_XATTR BIT(15) /* xattrs are invalid */ 261 #define NFS_INO_INVALID_NLINK BIT(16) /* cached nlinks is invalid */ 262 #define NFS_INO_INVALID_MODE BIT(17) /* cached mode is invalid */ 263 264 #define NFS_INO_INVALID_ATTR (NFS_INO_INVALID_CHANGE \ 265 | NFS_INO_INVALID_CTIME \ 266 | NFS_INO_INVALID_MTIME \ 267 | NFS_INO_INVALID_SIZE \ 268 | NFS_INO_INVALID_NLINK \ 269 | NFS_INO_INVALID_MODE \ 270 | NFS_INO_INVALID_OTHER) /* inode metadata is invalid */ 271 272 /* 273 * Bit offsets in flags field 274 */ 275 #define NFS_INO_STALE (1) /* possible stale inode */ 276 #define NFS_INO_ACL_LRU_SET (2) /* Inode is on the LRU list */ 277 #define NFS_INO_INVALIDATING (3) /* inode is being invalidated */ 278 #define NFS_INO_PRESERVE_UNLINKED (4) /* preserve file if removed while open */ 279 #define NFS_INO_FSCACHE (5) /* inode can be cached by FS-Cache */ 280 #define NFS_INO_LAYOUTCOMMIT (9) /* layoutcommit required */ 281 #define NFS_INO_LAYOUTCOMMITTING (10) /* layoutcommit inflight */ 282 #define NFS_INO_LAYOUTSTATS (11) /* layoutstats inflight */ 283 #define NFS_INO_ODIRECT (12) /* I/O setting is O_DIRECT */ 284 285 static inline struct nfs_inode *NFS_I(const struct inode *inode) 286 { 287 return container_of(inode, struct nfs_inode, vfs_inode); 288 } 289 290 static inline struct nfs_server *NFS_SB(const struct super_block *s) 291 { 292 return (struct nfs_server *)(s->s_fs_info); 293 } 294 295 static inline struct nfs_fh *NFS_FH(const struct inode *inode) 296 { 297 return &NFS_I(inode)->fh; 298 } 299 300 static inline struct nfs_server *NFS_SERVER(const struct inode *inode) 301 { 302 return NFS_SB(inode->i_sb); 303 } 304 305 static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode) 306 { 307 return NFS_SERVER(inode)->client; 308 } 309 310 static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode) 311 { 312 return NFS_SERVER(inode)->nfs_client->rpc_ops; 313 } 314 315 static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode) 316 { 317 struct nfs_server *nfss = NFS_SERVER(inode); 318 return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin; 319 } 320 321 static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode) 322 { 323 struct nfs_server *nfss = NFS_SERVER(inode); 324 return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax; 325 } 326 327 static inline int NFS_STALE(const struct inode *inode) 328 { 329 return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags); 330 } 331 332 static inline struct fscache_cookie *nfs_i_fscache(struct inode *inode) 333 { 334 #ifdef CONFIG_NFS_FSCACHE 335 return NFS_I(inode)->fscache; 336 #else 337 return NULL; 338 #endif 339 } 340 341 static inline __u64 NFS_FILEID(const struct inode *inode) 342 { 343 return NFS_I(inode)->fileid; 344 } 345 346 static inline void set_nfs_fileid(struct inode *inode, __u64 fileid) 347 { 348 NFS_I(inode)->fileid = fileid; 349 } 350 351 static inline void nfs_mark_for_revalidate(struct inode *inode) 352 { 353 struct nfs_inode *nfsi = NFS_I(inode); 354 355 spin_lock(&inode->i_lock); 356 nfsi->cache_validity |= NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL | 357 NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME | 358 NFS_INO_INVALID_SIZE; 359 if (S_ISDIR(inode->i_mode)) 360 nfsi->cache_validity |= NFS_INO_INVALID_DATA; 361 spin_unlock(&inode->i_lock); 362 } 363 364 static inline int nfs_server_capable(const struct inode *inode, int cap) 365 { 366 return NFS_SERVER(inode)->caps & cap; 367 } 368 369 /** 370 * nfs_save_change_attribute - Returns the inode attribute change cookie 371 * @dir - pointer to parent directory inode 372 * The "cache change attribute" is updated when we need to revalidate 373 * our dentry cache after a directory was seen to change on the server. 374 */ 375 static inline unsigned long nfs_save_change_attribute(struct inode *dir) 376 { 377 return NFS_I(dir)->cache_change_attribute; 378 } 379 380 /* 381 * linux/fs/nfs/inode.c 382 */ 383 extern int nfs_sync_mapping(struct address_space *mapping); 384 extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping); 385 extern void nfs_zap_caches(struct inode *); 386 extern void nfs_set_inode_stale(struct inode *inode); 387 extern void nfs_invalidate_atime(struct inode *); 388 extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *, 389 struct nfs_fattr *); 390 struct inode *nfs_ilookup(struct super_block *sb, struct nfs_fattr *, struct nfs_fh *); 391 extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *); 392 extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr); 393 extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr); 394 extern int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr); 395 extern int nfs_getattr(struct user_namespace *, const struct path *, 396 struct kstat *, u32, unsigned int); 397 extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *, const struct cred *); 398 extern void nfs_access_set_mask(struct nfs_access_entry *, u32); 399 extern int nfs_permission(struct user_namespace *, struct inode *, int); 400 extern int nfs_open(struct inode *, struct file *); 401 extern int nfs_attribute_cache_expired(struct inode *inode); 402 extern int nfs_revalidate_inode(struct inode *inode, unsigned long flags); 403 extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *); 404 extern int nfs_clear_invalid_mapping(struct address_space *mapping); 405 extern bool nfs_mapping_need_revalidate_inode(struct inode *inode); 406 extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping); 407 extern int nfs_revalidate_mapping_rcu(struct inode *inode); 408 extern int nfs_setattr(struct user_namespace *, struct dentry *, struct iattr *); 409 extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *); 410 extern void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr); 411 extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx); 412 extern void put_nfs_open_context(struct nfs_open_context *ctx); 413 extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode); 414 extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode, struct file *filp); 415 extern void nfs_inode_attach_open_context(struct nfs_open_context *ctx); 416 extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx); 417 extern void nfs_file_clear_open_context(struct file *flip); 418 extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx); 419 extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx); 420 extern u64 nfs_compat_user_ino64(u64 fileid); 421 extern void nfs_fattr_init(struct nfs_fattr *fattr); 422 extern void nfs_fattr_set_barrier(struct nfs_fattr *fattr); 423 extern unsigned long nfs_inc_attr_generation_counter(void); 424 425 extern struct nfs_fattr *nfs_alloc_fattr(void); 426 extern struct nfs_fattr *nfs_alloc_fattr_with_label(struct nfs_server *server); 427 428 static inline void nfs4_label_free(struct nfs4_label *label) 429 { 430 #ifdef CONFIG_NFS_V4_SECURITY_LABEL 431 if (label) { 432 kfree(label->label); 433 kfree(label); 434 } 435 #endif 436 } 437 438 static inline void nfs_free_fattr(const struct nfs_fattr *fattr) 439 { 440 if (fattr) 441 nfs4_label_free(fattr->label); 442 kfree(fattr); 443 } 444 445 extern struct nfs_fh *nfs_alloc_fhandle(void); 446 447 static inline void nfs_free_fhandle(const struct nfs_fh *fh) 448 { 449 kfree(fh); 450 } 451 452 #ifdef NFS_DEBUG 453 extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh); 454 static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh) 455 { 456 return _nfs_display_fhandle_hash(fh); 457 } 458 extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption); 459 #define nfs_display_fhandle(fh, caption) \ 460 do { \ 461 if (unlikely(nfs_debug & NFSDBG_FACILITY)) \ 462 _nfs_display_fhandle(fh, caption); \ 463 } while (0) 464 #else 465 static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh) 466 { 467 return 0; 468 } 469 static inline void nfs_display_fhandle(const struct nfs_fh *fh, 470 const char *caption) 471 { 472 } 473 #endif 474 475 /* 476 * linux/fs/nfs/nfsroot.c 477 */ 478 extern int nfs_root_data(char **root_device, char **root_data); /*__init*/ 479 /* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */ 480 extern __be32 root_nfs_parse_addr(char *name); /*__init*/ 481 482 /* 483 * linux/fs/nfs/file.c 484 */ 485 extern const struct file_operations nfs_file_operations; 486 #if IS_ENABLED(CONFIG_NFS_V4) 487 extern const struct file_operations nfs4_file_operations; 488 #endif /* CONFIG_NFS_V4 */ 489 extern const struct address_space_operations nfs_file_aops; 490 extern const struct address_space_operations nfs_dir_aops; 491 492 static inline struct nfs_open_context *nfs_file_open_context(struct file *filp) 493 { 494 return filp->private_data; 495 } 496 497 static inline const struct cred *nfs_file_cred(struct file *file) 498 { 499 if (file != NULL) { 500 struct nfs_open_context *ctx = 501 nfs_file_open_context(file); 502 if (ctx) 503 return ctx->cred; 504 } 505 return NULL; 506 } 507 508 /* 509 * linux/fs/nfs/direct.c 510 */ 511 int nfs_swap_rw(struct kiocb *iocb, struct iov_iter *iter); 512 ssize_t nfs_file_direct_read(struct kiocb *iocb, 513 struct iov_iter *iter, bool swap); 514 ssize_t nfs_file_direct_write(struct kiocb *iocb, 515 struct iov_iter *iter, bool swap); 516 517 /* 518 * linux/fs/nfs/dir.c 519 */ 520 extern const struct file_operations nfs_dir_operations; 521 extern const struct dentry_operations nfs_dentry_operations; 522 523 extern void nfs_force_lookup_revalidate(struct inode *dir); 524 extern void nfs_set_verifier(struct dentry * dentry, unsigned long verf); 525 #if IS_ENABLED(CONFIG_NFS_V4) 526 extern void nfs_clear_verifier_delegated(struct inode *inode); 527 #endif /* IS_ENABLED(CONFIG_NFS_V4) */ 528 extern struct dentry *nfs_add_or_obtain(struct dentry *dentry, 529 struct nfs_fh *fh, struct nfs_fattr *fattr); 530 extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh, 531 struct nfs_fattr *fattr); 532 extern int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags); 533 extern void nfs_access_zap_cache(struct inode *inode); 534 extern int nfs_access_get_cached(struct inode *inode, const struct cred *cred, 535 u32 *mask, bool may_block); 536 537 /* 538 * linux/fs/nfs/symlink.c 539 */ 540 extern const struct inode_operations nfs_symlink_inode_operations; 541 542 /* 543 * linux/fs/nfs/sysctl.c 544 */ 545 #ifdef CONFIG_SYSCTL 546 extern int nfs_register_sysctl(void); 547 extern void nfs_unregister_sysctl(void); 548 #else 549 #define nfs_register_sysctl() 0 550 #define nfs_unregister_sysctl() do { } while(0) 551 #endif 552 553 /* 554 * linux/fs/nfs/namespace.c 555 */ 556 extern const struct inode_operations nfs_mountpoint_inode_operations; 557 extern const struct inode_operations nfs_referral_inode_operations; 558 extern int nfs_mountpoint_expiry_timeout; 559 extern void nfs_release_automount_timer(void); 560 561 /* 562 * linux/fs/nfs/unlink.c 563 */ 564 extern void nfs_complete_unlink(struct dentry *dentry, struct inode *); 565 566 /* 567 * linux/fs/nfs/write.c 568 */ 569 extern int nfs_congestion_kb; 570 extern int nfs_writepage(struct page *page, struct writeback_control *wbc); 571 extern int nfs_writepages(struct address_space *, struct writeback_control *); 572 extern int nfs_flush_incompatible(struct file *file, struct page *page); 573 extern int nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int); 574 575 /* 576 * Try to write back everything synchronously (but check the 577 * return value!) 578 */ 579 extern int nfs_sync_inode(struct inode *inode); 580 extern int nfs_wb_all(struct inode *inode); 581 extern int nfs_wb_page(struct inode *inode, struct page *page); 582 int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio); 583 extern int nfs_commit_inode(struct inode *, int); 584 extern struct nfs_commit_data *nfs_commitdata_alloc(void); 585 extern void nfs_commit_free(struct nfs_commit_data *data); 586 bool nfs_commit_end(struct nfs_mds_commit_info *cinfo); 587 588 static inline bool nfs_have_writebacks(const struct inode *inode) 589 { 590 if (S_ISREG(inode->i_mode)) 591 return atomic_long_read(&NFS_I(inode)->nrequests) != 0; 592 return false; 593 } 594 595 /* 596 * linux/fs/nfs/read.c 597 */ 598 int nfs_read_folio(struct file *, struct folio *); 599 void nfs_readahead(struct readahead_control *); 600 601 /* 602 * inline functions 603 */ 604 605 static inline loff_t nfs_size_to_loff_t(__u64 size) 606 { 607 return min_t(u64, size, OFFSET_MAX); 608 } 609 610 static inline ino_t 611 nfs_fileid_to_ino_t(u64 fileid) 612 { 613 ino_t ino = (ino_t) fileid; 614 if (sizeof(ino_t) < sizeof(u64)) 615 ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8; 616 return ino; 617 } 618 619 #define NFS_JUKEBOX_RETRY_TIME (5 * HZ) 620 621 /* We need to block new opens while a file is being unlinked. 622 * If it is opened *before* we decide to unlink, we will silly-rename 623 * instead. If it is opened *after*, then we need to create or will fail. 624 * If we allow the two to race, we could end up with a file that is open 625 * but deleted on the server resulting in ESTALE. 626 * So use ->d_fsdata to record when the unlink is happening 627 * and block dentry revalidation while it is set. 628 */ 629 #define NFS_FSDATA_BLOCKED ((void*)1) 630 631 # undef ifdebug 632 # ifdef NFS_DEBUG 633 # define ifdebug(fac) if (unlikely(nfs_debug & NFSDBG_##fac)) 634 # define NFS_IFDEBUG(x) x 635 # else 636 # define ifdebug(fac) if (0) 637 # define NFS_IFDEBUG(x) 638 # endif 639 #endif 640