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1/* SPDX-License-Identifier: GPL-2.0 */2/*3 *  linux/include/linux/nfs_fs.h4 *5 *  Copyright (C) 1992  Rick Sladkey6 *7 *  OS-specific nfs filesystem definitions and declarations8 */9#ifndef _LINUX_NFS_FS_H10#define _LINUX_NFS_FS_H11 12#include <uapi/linux/nfs_fs.h>13 14 15/*16 * Enable dprintk() debugging support for nfs client.17 */18#ifdef CONFIG_NFS_DEBUG19# define NFS_DEBUG20#endif21 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#ifdef CONFIG_NFS_FSCACHE35#include <linux/netfs.h>36#endif37 38#include <linux/nfs.h>39#include <linux/nfs2.h>40#include <linux/nfs3.h>41#include <linux/nfs4.h>42#include <linux/nfs_xdr.h>43#include <linux/nfs_fs_sb.h>44 45#include <linux/mempool.h>46 47/*48 * These are the default for number of transports to different server IPs49 */50#define NFS_MAX_TRANSPORTS 1651 52/*53 * Size of the NFS directory verifier54 */55#define NFS_DIR_VERIFIER_SIZE		256 57/*58 * NFSv3/v4 Access mode cache entry59 */60struct nfs_access_entry {61	struct rb_node		rb_node;62	struct list_head	lru;63	kuid_t			fsuid;64	kgid_t			fsgid;65	struct group_info	*group_info;66	u64			timestamp;67	__u32			mask;68	struct rcu_head		rcu_head;69};70 71struct nfs_lock_context {72	refcount_t count;73	struct list_head list;74	struct nfs_open_context *open_context;75	fl_owner_t lockowner;76	atomic_t io_count;77	struct rcu_head	rcu_head;78};79 80struct nfs4_state;81struct nfs_open_context {82	struct nfs_lock_context lock_context;83	fl_owner_t flock_owner;84	struct dentry *dentry;85	const struct cred *cred;86	struct rpc_cred __rcu *ll_cred;	/* low-level cred - use to check for expiry */87	struct nfs4_state *state;88	fmode_t mode;89 90	unsigned long flags;91#define NFS_CONTEXT_BAD			(2)92#define NFS_CONTEXT_UNLOCK	(3)93#define NFS_CONTEXT_FILE_OPEN		(4)94	int error;95 96	struct list_head list;97	struct nfs4_threshold	*mdsthreshold;98	struct rcu_head	rcu_head;99};100 101struct nfs_open_dir_context {102	struct list_head list;103	atomic_t cache_hits;104	atomic_t cache_misses;105	unsigned long attr_gencount;106	__be32	verf[NFS_DIR_VERIFIER_SIZE];107	__u64 dir_cookie;108	__u64 last_cookie;109	pgoff_t page_index;110	unsigned int dtsize;111	bool force_clear;112	bool eof;113	struct rcu_head rcu_head;114};115 116/*117 * NFSv4 delegation118 */119struct nfs_delegation;120 121struct posix_acl;122 123struct nfs4_xattr_cache;124 125/*126 * nfs fs inode data in memory127 */128struct nfs_inode {129	/*130	 * The 64bit 'inode number'131	 */132	__u64 fileid;133 134	/*135	 * NFS file handle136	 */137	struct nfs_fh		fh;138 139	/*140	 * Various flags141	 */142	unsigned long		flags;			/* atomic bit ops */143	unsigned long		cache_validity;		/* bit mask */144 145	/*146	 * read_cache_jiffies is when we started read-caching this inode.147	 * attrtimeo is for how long the cached information is assumed148	 * to be valid. A successful attribute revalidation doubles149	 * attrtimeo (up to acregmax/acdirmax), a failure resets it to150	 * acregmin/acdirmin.151	 *152	 * We need to revalidate the cached attrs for this inode if153	 *154	 *	jiffies - read_cache_jiffies >= attrtimeo155	 *156	 * Please note the comparison is greater than or equal157	 * so that zero timeout values can be specified.158	 */159	unsigned long		read_cache_jiffies;160	unsigned long		attrtimeo;161	unsigned long		attrtimeo_timestamp;162 163	unsigned long		attr_gencount;164 165	struct rb_root		access_cache;166	struct list_head	access_cache_entry_lru;167	struct list_head	access_cache_inode_lru;168 169	union {170		/* Directory */171		struct {172			/* "Generation counter" for the attribute cache.173			 * This is bumped whenever we update the metadata174			 * on the server.175			 */176			unsigned long	cache_change_attribute;177			/*178			 * This is the cookie verifier used for NFSv3 readdir179			 * operations180			 */181			__be32		cookieverf[NFS_DIR_VERIFIER_SIZE];182			/* Readers: in-flight sillydelete RPC calls */183			/* Writers: rmdir */184			struct rw_semaphore	rmdir_sem;185		};186		/* Regular file */187		struct {188			atomic_long_t	nrequests;189			atomic_long_t	redirtied_pages;190			struct nfs_mds_commit_info commit_info;191			struct mutex	commit_mutex;192		};193	};194 195	/* Open contexts for shared mmap writes */196	struct list_head	open_files;197 198	/* Keep track of out-of-order replies.199	 * The ooo array contains start/end pairs of200	 * numbers from the changeid sequence when201	 * the inode's iversion has been updated.202	 * It also contains end/start pair (i.e. reverse order)203	 * of sections of the changeid sequence that have204	 * been seen in replies from the server.205	 * Normally these should match and when both206	 * A:B and B:A are found in ooo, they are both removed.207	 * And if a reply with A:B causes an iversion update208	 * of A:B, then neither are added.209	 * When a reply has pre_change that doesn't match210	 * iversion, then the changeid pair and any consequent211	 * change in iversion ARE added.  Later replies212	 * might fill in the gaps, or possibly a gap is caused213	 * by a change from another client.214	 * When a file or directory is opened, if the ooo table215	 * is not empty, then we assume the gaps were due to216	 * another client and we invalidate the cached data.217	 *218	 * We can only track a limited number of concurrent gaps.219	 * Currently that limit is 16.220	 * We allocate the table on demand.  If there is insufficient221	 * memory, then we probably cannot cache the file anyway222	 * so there is no loss.223	 */224	struct {225		int cnt;226		struct {227			u64 start, end;228		} gap[16];229	} *ooo;230 231#if IS_ENABLED(CONFIG_NFS_V4)232	struct nfs4_cached_acl	*nfs4_acl;233        /* NFSv4 state */234	struct list_head	open_states;235	struct nfs_delegation __rcu *delegation;236	struct rw_semaphore	rwsem;237 238	/* pNFS layout information */239	struct pnfs_layout_hdr *layout;240#endif /* CONFIG_NFS_V4*/241	/* how many bytes have been written/read and how many bytes queued up */242	__u64 write_io;243	__u64 read_io;244#ifdef CONFIG_NFS_V4_2245	struct nfs4_xattr_cache *xattr_cache;246#endif247	union {248		struct inode		vfs_inode;249#ifdef CONFIG_NFS_FSCACHE250		struct netfs_inode	netfs; /* netfs context and VFS inode */251#endif252	};253};254 255struct nfs4_copy_state {256	struct list_head	copies;257	struct list_head	src_copies;258	nfs4_stateid		stateid;259	struct completion	completion;260	uint64_t		count;261	struct nfs_writeverf	verf;262	int			error;263	int			flags;264	struct nfs4_state	*parent_src_state;265	struct nfs4_state	*parent_dst_state;266};267 268/*269 * Access bit flags270 */271#define NFS_ACCESS_READ        0x0001272#define NFS_ACCESS_LOOKUP      0x0002273#define NFS_ACCESS_MODIFY      0x0004274#define NFS_ACCESS_EXTEND      0x0008275#define NFS_ACCESS_DELETE      0x0010276#define NFS_ACCESS_EXECUTE     0x0020277#define NFS_ACCESS_XAREAD      0x0040278#define NFS_ACCESS_XAWRITE     0x0080279#define NFS_ACCESS_XALIST      0x0100280 281/*282 * Cache validity bit flags283 */284#define NFS_INO_INVALID_DATA	BIT(1)		/* cached data is invalid */285#define NFS_INO_INVALID_ATIME	BIT(2)		/* cached atime is invalid */286#define NFS_INO_INVALID_ACCESS	BIT(3)		/* cached access cred invalid */287#define NFS_INO_INVALID_ACL	BIT(4)		/* cached acls are invalid */288#define NFS_INO_REVAL_FORCED	BIT(6)		/* force revalidation ignoring a delegation */289#define NFS_INO_INVALID_LABEL	BIT(7)		/* cached label is invalid */290#define NFS_INO_INVALID_CHANGE	BIT(8)		/* cached change is invalid */291#define NFS_INO_INVALID_CTIME	BIT(9)		/* cached ctime is invalid */292#define NFS_INO_INVALID_MTIME	BIT(10)		/* cached mtime is invalid */293#define NFS_INO_INVALID_SIZE	BIT(11)		/* cached size is invalid */294#define NFS_INO_INVALID_OTHER	BIT(12)		/* other attrs are invalid */295#define NFS_INO_DATA_INVAL_DEFER	\296				BIT(13)		/* Deferred cache invalidation */297#define NFS_INO_INVALID_BLOCKS	BIT(14)         /* cached blocks are invalid */298#define NFS_INO_INVALID_XATTR	BIT(15)		/* xattrs are invalid */299#define NFS_INO_INVALID_NLINK	BIT(16)		/* cached nlinks is invalid */300#define NFS_INO_INVALID_MODE	BIT(17)		/* cached mode is invalid */301 302#define NFS_INO_INVALID_ATTR	(NFS_INO_INVALID_CHANGE \303		| NFS_INO_INVALID_CTIME \304		| NFS_INO_INVALID_MTIME \305		| NFS_INO_INVALID_SIZE \306		| NFS_INO_INVALID_NLINK \307		| NFS_INO_INVALID_MODE \308		| NFS_INO_INVALID_OTHER)	/* inode metadata is invalid */309 310/*311 * Bit offsets in flags field312 */313#define NFS_INO_STALE		(1)		/* possible stale inode */314#define NFS_INO_ACL_LRU_SET	(2)		/* Inode is on the LRU list */315#define NFS_INO_INVALIDATING	(3)		/* inode is being invalidated */316#define NFS_INO_PRESERVE_UNLINKED (4)		/* preserve file if removed while open */317#define NFS_INO_LAYOUTCOMMIT	(9)		/* layoutcommit required */318#define NFS_INO_LAYOUTCOMMITTING (10)		/* layoutcommit inflight */319#define NFS_INO_LAYOUTSTATS	(11)		/* layoutstats inflight */320#define NFS_INO_ODIRECT		(12)		/* I/O setting is O_DIRECT */321 322static inline struct nfs_inode *NFS_I(const struct inode *inode)323{324	return container_of(inode, struct nfs_inode, vfs_inode);325}326 327static inline struct nfs_server *NFS_SB(const struct super_block *s)328{329	return (struct nfs_server *)(s->s_fs_info);330}331 332static inline struct nfs_fh *NFS_FH(const struct inode *inode)333{334	return &NFS_I(inode)->fh;335}336 337static inline struct nfs_server *NFS_SERVER(const struct inode *inode)338{339	return NFS_SB(inode->i_sb);340}341 342static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode)343{344	return NFS_SERVER(inode)->client;345}346 347static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode)348{349	return NFS_SERVER(inode)->nfs_client->rpc_ops;350}351 352static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode)353{354	struct nfs_server *nfss = NFS_SERVER(inode);355	return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin;356}357 358static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode)359{360	struct nfs_server *nfss = NFS_SERVER(inode);361	return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax;362}363 364static inline int NFS_STALE(const struct inode *inode)365{366	return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);367}368 369static inline __u64 NFS_FILEID(const struct inode *inode)370{371	return NFS_I(inode)->fileid;372}373 374static inline void set_nfs_fileid(struct inode *inode, __u64 fileid)375{376	NFS_I(inode)->fileid = fileid;377}378 379static inline void nfs_mark_for_revalidate(struct inode *inode)380{381	struct nfs_inode *nfsi = NFS_I(inode);382 383	spin_lock(&inode->i_lock);384	nfsi->cache_validity |= NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL |385				NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME |386				NFS_INO_INVALID_SIZE;387	if (S_ISDIR(inode->i_mode))388		nfsi->cache_validity |= NFS_INO_INVALID_DATA;389	spin_unlock(&inode->i_lock);390}391 392static inline int nfs_server_capable(const struct inode *inode, int cap)393{394	return NFS_SERVER(inode)->caps & cap;395}396 397/**398 * nfs_save_change_attribute - Returns the inode attribute change cookie399 * @dir - pointer to parent directory inode400 * The "cache change attribute" is updated when we need to revalidate401 * our dentry cache after a directory was seen to change on the server.402 */403static inline unsigned long nfs_save_change_attribute(struct inode *dir)404{405	return NFS_I(dir)->cache_change_attribute;406}407 408/*409 * linux/fs/nfs/inode.c410 */411extern int nfs_sync_mapping(struct address_space *mapping);412extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping);413extern void nfs_zap_caches(struct inode *);414extern void nfs_set_inode_stale(struct inode *inode);415extern void nfs_invalidate_atime(struct inode *);416extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,417				struct nfs_fattr *);418struct inode *nfs_ilookup(struct super_block *sb, struct nfs_fattr *, struct nfs_fh *);419extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);420extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);421extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);422extern int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr);423extern int nfs_getattr(struct mnt_idmap *, const struct path *,424		       struct kstat *, u32, unsigned int);425extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *, const struct cred *);426extern void nfs_access_set_mask(struct nfs_access_entry *, u32);427extern int nfs_permission(struct mnt_idmap *, struct inode *, int);428extern int nfs_open(struct inode *, struct file *);429extern int nfs_attribute_cache_expired(struct inode *inode);430extern int nfs_revalidate_inode(struct inode *inode, unsigned long flags);431extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);432extern int nfs_clear_invalid_mapping(struct address_space *mapping);433extern bool nfs_mapping_need_revalidate_inode(struct inode *inode);434extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);435extern int nfs_revalidate_mapping_rcu(struct inode *inode);436extern int nfs_setattr(struct mnt_idmap *, struct dentry *, struct iattr *);437extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *);438extern void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr);439extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);440extern void put_nfs_open_context(struct nfs_open_context *ctx);441extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode);442extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode, struct file *filp);443extern void nfs_inode_attach_open_context(struct nfs_open_context *ctx);444extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);445extern void nfs_file_clear_open_context(struct file *flip);446extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx);447extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx);448extern u64 nfs_compat_user_ino64(u64 fileid);449extern void nfs_fattr_init(struct nfs_fattr *fattr);450extern void nfs_fattr_set_barrier(struct nfs_fattr *fattr);451extern unsigned long nfs_inc_attr_generation_counter(void);452 453extern struct nfs_fattr *nfs_alloc_fattr(void);454extern struct nfs_fattr *nfs_alloc_fattr_with_label(struct nfs_server *server);455 456static inline void nfs4_label_free(struct nfs4_label *label)457{458#ifdef CONFIG_NFS_V4_SECURITY_LABEL459	if (label) {460		kfree(label->label);461		kfree(label);462	}463#endif464}465 466static inline void nfs_free_fattr(const struct nfs_fattr *fattr)467{468	if (fattr)469		nfs4_label_free(fattr->label);470	kfree(fattr);471}472 473extern struct nfs_fh *nfs_alloc_fhandle(void);474 475static inline void nfs_free_fhandle(const struct nfs_fh *fh)476{477	kfree(fh);478}479 480#ifdef NFS_DEBUG481extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh);482static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)483{484	return _nfs_display_fhandle_hash(fh);485}486extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption);487#define nfs_display_fhandle(fh, caption)			\488	do {							\489		if (unlikely(nfs_debug & NFSDBG_FACILITY))	\490			_nfs_display_fhandle(fh, caption);	\491	} while (0)492#else493static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)494{495	return 0;496}497static inline void nfs_display_fhandle(const struct nfs_fh *fh,498				       const char *caption)499{500}501#endif502 503/*504 * linux/fs/nfs/nfsroot.c505 */506extern int  nfs_root_data(char **root_device, char **root_data); /*__init*/507/* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */508extern __be32 root_nfs_parse_addr(char *name); /*__init*/509 510/*511 * linux/fs/nfs/file.c512 */513extern const struct file_operations nfs_file_operations;514#if IS_ENABLED(CONFIG_NFS_V4)515extern const struct file_operations nfs4_file_operations;516#endif /* CONFIG_NFS_V4 */517extern const struct address_space_operations nfs_file_aops;518extern const struct address_space_operations nfs_dir_aops;519 520static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)521{522	return filp->private_data;523}524 525static inline const struct cred *nfs_file_cred(struct file *file)526{527	if (file != NULL) {528		struct nfs_open_context *ctx =529			nfs_file_open_context(file);530		if (ctx)531			return ctx->cred;532	}533	return NULL;534}535 536/*537 * linux/fs/nfs/direct.c538 */539int nfs_swap_rw(struct kiocb *iocb, struct iov_iter *iter);540ssize_t nfs_file_direct_read(struct kiocb *iocb,541			     struct iov_iter *iter, bool swap);542ssize_t nfs_file_direct_write(struct kiocb *iocb,543			      struct iov_iter *iter, bool swap);544 545/*546 * linux/fs/nfs/dir.c547 */548extern const struct file_operations nfs_dir_operations;549extern const struct dentry_operations nfs_dentry_operations;550 551extern void nfs_force_lookup_revalidate(struct inode *dir);552extern void nfs_set_verifier(struct dentry * dentry, unsigned long verf);553#if IS_ENABLED(CONFIG_NFS_V4)554extern void nfs_clear_verifier_delegated(struct inode *inode);555#endif /* IS_ENABLED(CONFIG_NFS_V4) */556extern struct dentry *nfs_add_or_obtain(struct dentry *dentry,557			struct nfs_fh *fh, struct nfs_fattr *fattr);558extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh,559			struct nfs_fattr *fattr);560extern int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags);561extern void nfs_access_zap_cache(struct inode *inode);562extern int nfs_access_get_cached(struct inode *inode, const struct cred *cred,563				 u32 *mask, bool may_block);564extern int nfs_atomic_open_v23(struct inode *dir, struct dentry *dentry,565			       struct file *file, unsigned int open_flags,566			       umode_t mode);567 568/*569 * linux/fs/nfs/symlink.c570 */571extern const struct inode_operations nfs_symlink_inode_operations;572 573/*574 * linux/fs/nfs/sysctl.c575 */576#ifdef CONFIG_SYSCTL577extern int nfs_register_sysctl(void);578extern void nfs_unregister_sysctl(void);579#else580#define nfs_register_sysctl() 0581#define nfs_unregister_sysctl() do { } while(0)582#endif583 584/*585 * linux/fs/nfs/namespace.c586 */587extern const struct inode_operations nfs_mountpoint_inode_operations;588extern const struct inode_operations nfs_referral_inode_operations;589extern int nfs_mountpoint_expiry_timeout;590extern void nfs_release_automount_timer(void);591 592/*593 * linux/fs/nfs/unlink.c594 */595extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);596 597/*598 * linux/fs/nfs/write.c599 */600extern int  nfs_congestion_kb;601extern int  nfs_writepages(struct address_space *, struct writeback_control *);602extern int  nfs_flush_incompatible(struct file *file, struct folio *folio);603extern int  nfs_update_folio(struct file *file, struct folio *folio,604			     unsigned int offset, unsigned int count);605 606/*607 * Try to write back everything synchronously (but check the608 * return value!)609 */610extern int nfs_sync_inode(struct inode *inode);611extern int nfs_wb_all(struct inode *inode);612extern int nfs_wb_folio(struct inode *inode, struct folio *folio);613int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio);614extern int  nfs_commit_inode(struct inode *, int);615extern struct nfs_commit_data *nfs_commitdata_alloc(void);616extern void nfs_commit_free(struct nfs_commit_data *data);617void nfs_commit_begin(struct nfs_mds_commit_info *cinfo);618bool nfs_commit_end(struct nfs_mds_commit_info *cinfo);619 620static inline bool nfs_have_writebacks(const struct inode *inode)621{622	if (S_ISREG(inode->i_mode))623		return atomic_long_read(&NFS_I(inode)->nrequests) != 0;624	return false;625}626 627/*628 * linux/fs/nfs/read.c629 */630int  nfs_read_folio(struct file *, struct folio *);631void nfs_readahead(struct readahead_control *);632 633/*634 * inline functions635 */636 637static inline loff_t nfs_size_to_loff_t(__u64 size)638{639	return min_t(u64, size, OFFSET_MAX);640}641 642static inline ino_t643nfs_fileid_to_ino_t(u64 fileid)644{645	ino_t ino = (ino_t) fileid;646	if (sizeof(ino_t) < sizeof(u64))647		ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;648	return ino;649}650 651static inline void nfs_ooo_clear(struct nfs_inode *nfsi)652{653	nfsi->cache_validity &= ~NFS_INO_DATA_INVAL_DEFER;654	kfree(nfsi->ooo);655	nfsi->ooo = NULL;656}657 658static inline bool nfs_ooo_test(struct nfs_inode *nfsi)659{660	return (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER) ||661		(nfsi->ooo && nfsi->ooo->cnt > 0);662 663}664 665#define NFS_JUKEBOX_RETRY_TIME (5 * HZ)666 667/* We need to block new opens while a file is being unlinked.668 * If it is opened *before* we decide to unlink, we will silly-rename669 * instead. If it is opened *after*, then we need to create or will fail.670 * If we allow the two to race, we could end up with a file that is open671 * but deleted on the server resulting in ESTALE.672 * So use ->d_fsdata to record when the unlink is happening673 * and block dentry revalidation while it is set.674 */675#define NFS_FSDATA_BLOCKED ((void*)1)676 677# undef ifdebug678# ifdef NFS_DEBUG679#  define ifdebug(fac)		if (unlikely(nfs_debug & NFSDBG_##fac))680#  define NFS_IFDEBUG(x)	x681# else682#  define ifdebug(fac)		if (0)683#  define NFS_IFDEBUG(x)684# endif685#endif686