/*
   *  linux/include/linux/nfs_fs.h
   *
   *  Copyright (C) 1992  Rick Sladkey
   *
   *  OS-specific nfs filesystem definitions and declarations
   */
  #ifndef _LINUX_NFS_FS_H
  #define _LINUX_NFS_FS_H
  
  #include <uapi/linux/nfs_fs.h>
  
  
  /*
   * Enable dprintk() debugging support for nfs client.
   */
  #ifdef CONFIG_NFS_DEBUG
  # define NFS_DEBUG
  #endif
  
  #include <linux/in.h>
  #include <linux/mm.h>
  #include <linux/pagemap.h>
  #include <linux/rbtree.h>
  #include <linux/rwsem.h>
  #include <linux/wait.h>
  
  #include <linux/sunrpc/debug.h>
  #include <linux/sunrpc/auth.h>
  #include <linux/sunrpc/clnt.h>
  
  #include <linux/nfs.h>
  #include <linux/nfs2.h>
  #include <linux/nfs3.h>
  #include <linux/nfs4.h>
  #include <linux/nfs_xdr.h>
  #include <linux/nfs_fs_sb.h>
  
  #include <linux/mempool.h>
  
  /*
   * These are the default flags for swap requests
   */
  #define NFS_RPC_SWAPFLAGS		(RPC_TASK_SWAPPER|RPC_TASK_ROOTCREDS)
  
  /*
   * NFSv3/v4 Access mode cache entry
   */
  struct nfs_access_entry {
  	struct rb_node		rb_node;
  	struct list_head	lru;
  	unsigned long		jiffies;
  	struct rpc_cred *	cred;
  	int			mask;
  	struct rcu_head		rcu_head;
  };
  
  struct nfs_lockowner {
  	fl_owner_t l_owner;
  	pid_t l_pid;
  };
  
  #define NFS_IO_INPROGRESS 0
  struct nfs_io_counter {
  	unsigned long flags;
  	atomic_t io_count;
  };
  
  struct nfs_lock_context {
  	atomic_t count;
  	struct list_head list;
  	struct nfs_open_context *open_context;
  	struct nfs_lockowner lockowner;
  	struct nfs_io_counter io_count;
  };
  
  struct nfs4_state;
  struct nfs_open_context {
  	struct nfs_lock_context lock_context;
  	struct dentry *dentry;
  	struct rpc_cred *cred;
  	struct nfs4_state *state;
  	fmode_t mode;
  
  	unsigned long flags;
  #define NFS_CONTEXT_ERROR_WRITE		(0)
  #define NFS_CONTEXT_RESEND_WRITES	(1)
  #define NFS_CONTEXT_BAD			(2)
  	int error;
  
  	struct list_head list;
  	struct nfs4_threshold	*mdsthreshold;
  };
  
  struct nfs_open_dir_context {
  	struct list_head list;
  	struct rpc_cred *cred;
  	unsigned long attr_gencount;
  	__u64 dir_cookie;
  	__u64 dup_cookie;
  	signed char duped;
  };
  
  /*
   * NFSv4 delegation
   */
  struct nfs_delegation;
  
  struct posix_acl;
  
  /*
   * nfs fs inode data in memory
   */
  struct nfs_inode {
  	/*
  	 * The 64bit 'inode number'
  	 */
  	__u64 fileid;
  
  	/*
  	 * NFS file handle
  	 */
  	struct nfs_fh		fh;
  
  	/*
  	 * Various flags
  	 */
  	unsigned long		flags;			/* atomic bit ops */
  	unsigned long		cache_validity;		/* bit mask */
  
  	/*
  	 * read_cache_jiffies is when we started read-caching this inode.
  	 * attrtimeo is for how long the cached information is assumed
  	 * to be valid. A successful attribute revalidation doubles
  	 * attrtimeo (up to acregmax/acdirmax), a failure resets it to
  	 * acregmin/acdirmin.
  	 *
  	 * We need to revalidate the cached attrs for this inode if
  	 *
  	 *	jiffies - read_cache_jiffies >= attrtimeo
  	 *
  	 * Please note the comparison is greater than or equal
  	 * so that zero timeout values can be specified.
  	 */
  	unsigned long		read_cache_jiffies;
  	unsigned long		attrtimeo;
  	unsigned long		attrtimeo_timestamp;
  
  	unsigned long		attr_gencount;
  	/* "Generation counter" for the attribute cache. This is
  	 * bumped whenever we update the metadata on the
  	 * server.
  	 */
  	unsigned long		cache_change_attribute;
  
  	struct rb_root		access_cache;
  	struct list_head	access_cache_entry_lru;
  	struct list_head	access_cache_inode_lru;
  
  	/*
  	 * This is the cookie verifier used for NFSv3 readdir
  	 * operations
  	 */
  	__be32			cookieverf[2];
  
  	unsigned long		nrequests;
  	struct nfs_mds_commit_info commit_info;
  
  	/* Open contexts for shared mmap writes */
  	struct list_head	open_files;
  
  	/* Number of in-flight sillydelete RPC calls */
  	atomic_t		silly_count;
  	/* List of deferred sillydelete requests */
  	struct hlist_head	silly_list;
  	wait_queue_head_t	waitqueue;
  
  #if IS_ENABLED(CONFIG_NFS_V4)
  	struct nfs4_cached_acl	*nfs4_acl;
          /* NFSv4 state */
  	struct list_head	open_states;
  	struct nfs_delegation __rcu *delegation;
  	struct rw_semaphore	rwsem;
  
  	/* pNFS layout information */
  	struct pnfs_layout_hdr *layout;
  #endif /* CONFIG_NFS_V4*/
  	/* how many bytes have been written/read and how many bytes queued up */
  	__u64 write_io;
  	__u64 read_io;
  #ifdef CONFIG_NFS_FSCACHE
  	struct fscache_cookie	*fscache;
  #endif
  	struct inode		vfs_inode;
  };
  
  /*
   * Cache validity bit flags
   */
  #define NFS_INO_INVALID_ATTR	0x0001		/* cached attrs are invalid */
  #define NFS_INO_INVALID_DATA	0x0002		/* cached data is invalid */
  #define NFS_INO_INVALID_ATIME	0x0004		/* cached atime is invalid */
  #define NFS_INO_INVALID_ACCESS	0x0008		/* cached access cred invalid */
  #define NFS_INO_INVALID_ACL	0x0010		/* cached acls are invalid */
  #define NFS_INO_REVAL_PAGECACHE	0x0020		/* must revalidate pagecache */
  #define NFS_INO_REVAL_FORCED	0x0040		/* force revalidation ignoring a delegation */
  #define NFS_INO_INVALID_LABEL	0x0080		/* cached label is invalid */
  
  /*
   * Bit offsets in flags field
   */
  #define NFS_INO_ADVISE_RDPLUS	(0)		/* advise readdirplus */
  #define NFS_INO_STALE		(1)		/* possible stale inode */
  #define NFS_INO_ACL_LRU_SET	(2)		/* Inode is on the LRU list */
  #define NFS_INO_INVALIDATING	(3)		/* inode is being invalidated */
  #define NFS_INO_FLUSHING	(4)		/* inode is flushing out data */
  #define NFS_INO_FSCACHE		(5)		/* inode can be cached by FS-Cache */
  #define NFS_INO_FSCACHE_LOCK	(6)		/* FS-Cache cookie management lock */
  #define NFS_INO_COMMIT		(7)		/* inode is committing unstable writes */
  #define NFS_INO_LAYOUTCOMMIT	(9)		/* layoutcommit required */
  #define NFS_INO_LAYOUTCOMMITTING (10)		/* layoutcommit inflight */
  #define NFS_INO_LAYOUTSTATS	(11)		/* layoutstats inflight */
  
  static inline struct nfs_inode *NFS_I(const struct inode *inode)
  {
  	return container_of(inode, struct nfs_inode, vfs_inode);
  }
  
  static inline struct nfs_server *NFS_SB(const struct super_block *s)
  {
  	return (struct nfs_server *)(s->s_fs_info);
  }
  
  static inline struct nfs_fh *NFS_FH(const struct inode *inode)
  {
  	return &NFS_I(inode)->fh;
  }
  
  static inline struct nfs_server *NFS_SERVER(const struct inode *inode)
  {
  	return NFS_SB(inode->i_sb);
  }
  
  static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode)
  {
  	return NFS_SERVER(inode)->client;
  }
  
  static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode)
  {
  	return NFS_SERVER(inode)->nfs_client->rpc_ops;
  }
  
  static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode)
  {
  	struct nfs_server *nfss = NFS_SERVER(inode);
  	return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin;
  }
  
  static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode)
  {
  	struct nfs_server *nfss = NFS_SERVER(inode);
  	return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax;
  }
  
  static inline int NFS_STALE(const struct inode *inode)
  {
  	return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
  }
  
  static inline struct fscache_cookie *nfs_i_fscache(struct inode *inode)
  {
  #ifdef CONFIG_NFS_FSCACHE
  	return NFS_I(inode)->fscache;
  #else
  	return NULL;
  #endif
  }
  
  static inline __u64 NFS_FILEID(const struct inode *inode)
  {
  	return NFS_I(inode)->fileid;
  }
  
  static inline void set_nfs_fileid(struct inode *inode, __u64 fileid)
  {
  	NFS_I(inode)->fileid = fileid;
  }
  
  static inline void nfs_mark_for_revalidate(struct inode *inode)
  {
  	struct nfs_inode *nfsi = NFS_I(inode);
  
  	spin_lock(&inode->i_lock);
  	nfsi->cache_validity |= NFS_INO_INVALID_ATTR |
  				NFS_INO_REVAL_PAGECACHE |
  				NFS_INO_INVALID_ACCESS |
  				NFS_INO_INVALID_ACL;
  	if (S_ISDIR(inode->i_mode))
  		nfsi->cache_validity |= NFS_INO_INVALID_DATA;
  	spin_unlock(&inode->i_lock);
  }
  
  static inline int nfs_server_capable(struct inode *inode, int cap)
  {
  	return NFS_SERVER(inode)->caps & cap;
  }
  
  static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
  {
  	dentry->d_time = verf;
  }
  
  /**
   * nfs_save_change_attribute - Returns the inode attribute change cookie
   * @dir - pointer to parent directory inode
   * The "change attribute" is updated every time we finish an operation
   * that will result in a metadata change on the server.
   */
  static inline unsigned long nfs_save_change_attribute(struct inode *dir)
  {
  	return NFS_I(dir)->cache_change_attribute;
  }
  
  /**
   * nfs_verify_change_attribute - Detects NFS remote directory changes
   * @dir - pointer to parent directory inode
   * @chattr - previously saved change attribute
   * Return "false" if the verifiers doesn't match the change attribute.
   * This would usually indicate that the directory contents have changed on
   * the server, and that any dentries need revalidating.
   */
  static inline int nfs_verify_change_attribute(struct inode *dir, unsigned long chattr)
  {
  	return chattr == NFS_I(dir)->cache_change_attribute;
  }
  
  /*
   * linux/fs/nfs/inode.c
   */
  extern int nfs_sync_mapping(struct address_space *mapping);
  extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping);
  extern void nfs_zap_caches(struct inode *);
  extern void nfs_invalidate_atime(struct inode *);
  extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
  				struct nfs_fattr *, struct nfs4_label *);
  extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
  extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
  extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
  extern int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr);
  extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
  extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *);
  extern void nfs_access_set_mask(struct nfs_access_entry *, u32);
  extern int nfs_permission(struct inode *, int);
  extern int nfs_open(struct inode *, struct file *);
  extern int nfs_attribute_timeout(struct inode *inode);
  extern int nfs_attribute_cache_expired(struct inode *inode);
  extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode);
  extern int nfs_revalidate_inode_rcu(struct nfs_server *server, struct inode *inode);
  extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
  extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
  extern int nfs_revalidate_mapping_protected(struct inode *inode, struct address_space *mapping);
  extern int nfs_setattr(struct dentry *, struct iattr *);
  extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *);
  extern void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
  				struct nfs4_label *label);
  extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
  extern void put_nfs_open_context(struct nfs_open_context *ctx);
  extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode);
  extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode);
  extern void nfs_inode_attach_open_context(struct nfs_open_context *ctx);
  extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);
  extern void nfs_file_clear_open_context(struct file *flip);
  extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx);
  extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx);
  extern u64 nfs_compat_user_ino64(u64 fileid);
  extern void nfs_fattr_init(struct nfs_fattr *fattr);
  extern void nfs_fattr_set_barrier(struct nfs_fattr *fattr);
  extern unsigned long nfs_inc_attr_generation_counter(void);
  
  extern struct nfs_fattr *nfs_alloc_fattr(void);
  
  static inline void nfs_free_fattr(const struct nfs_fattr *fattr)
  {
  	kfree(fattr);
  }
  
  extern struct nfs_fh *nfs_alloc_fhandle(void);
  
  static inline void nfs_free_fhandle(const struct nfs_fh *fh)
  {
  	kfree(fh);
  }
  
  #ifdef NFS_DEBUG
  extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh);
  static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
  {
  	return _nfs_display_fhandle_hash(fh);
  }
  extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption);
  #define nfs_display_fhandle(fh, caption)			\
  	do {							\
  		if (unlikely(nfs_debug & NFSDBG_FACILITY))	\
  			_nfs_display_fhandle(fh, caption);	\
  	} while (0)
  #else
  static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
  {
  	return 0;
  }
  static inline void nfs_display_fhandle(const struct nfs_fh *fh,
  				       const char *caption)
  {
  }
  #endif
  
  /*
   * linux/fs/nfs/nfsroot.c
   */
  extern int  nfs_root_data(char **root_device, char **root_data); /*__init*/
  /* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
  extern __be32 root_nfs_parse_addr(char *name); /*__init*/
  
  /*
   * linux/fs/nfs/file.c
   */
  extern const struct file_operations nfs_file_operations;
  #if IS_ENABLED(CONFIG_NFS_V4)
  extern const struct file_operations nfs4_file_operations;
  #endif /* CONFIG_NFS_V4 */
  extern const struct address_space_operations nfs_file_aops;
  extern const struct address_space_operations nfs_dir_aops;
  
  static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
  {
  	return filp->private_data;
  }
  
  static inline struct rpc_cred *nfs_file_cred(struct file *file)
  {
  	if (file != NULL) {
  		struct nfs_open_context *ctx =
  			nfs_file_open_context(file);
  		if (ctx)
  			return ctx->cred;
  	}
  	return NULL;
  }
  
  /*
   * linux/fs/nfs/direct.c
   */
  extern ssize_t nfs_direct_IO(struct kiocb *, struct iov_iter *, loff_t);
  extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
  			struct iov_iter *iter,
  			loff_t pos);
  extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
  			struct iov_iter *iter);
  
  /*
   * linux/fs/nfs/dir.c
   */
  extern const struct file_operations nfs_dir_operations;
  extern const struct dentry_operations nfs_dentry_operations;
  
  extern void nfs_force_lookup_revalidate(struct inode *dir);
  extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh,
  			struct nfs_fattr *fattr, struct nfs4_label *label);
  extern int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags);
  extern void nfs_access_zap_cache(struct inode *inode);
  
  /*
   * linux/fs/nfs/symlink.c
   */
  extern const struct inode_operations nfs_symlink_inode_operations;
  
  /*
   * linux/fs/nfs/sysctl.c
   */
  #ifdef CONFIG_SYSCTL
  extern int nfs_register_sysctl(void);
  extern void nfs_unregister_sysctl(void);
  #else
  #define nfs_register_sysctl() 0
  #define nfs_unregister_sysctl() do { } while(0)
  #endif
  
  /*
   * linux/fs/nfs/namespace.c
   */
  extern const struct inode_operations nfs_mountpoint_inode_operations;
  extern const struct inode_operations nfs_referral_inode_operations;
  extern int nfs_mountpoint_expiry_timeout;
  extern void nfs_release_automount_timer(void);
  
  /*
   * linux/fs/nfs/unlink.c
   */
  extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);
  extern void nfs_wait_on_sillyrename(struct dentry *dentry);
  extern void nfs_block_sillyrename(struct dentry *dentry);
  extern void nfs_unblock_sillyrename(struct dentry *dentry);
  
  /*
   * linux/fs/nfs/write.c
   */
  extern int  nfs_congestion_kb;
  extern int  nfs_writepage(struct page *page, struct writeback_control *wbc);
  extern int  nfs_writepages(struct address_space *, struct writeback_control *);
  extern int  nfs_flush_incompatible(struct file *file, struct page *page);
  extern int  nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
  
  /*
   * Try to write back everything synchronously (but check the
   * return value!)
   */
  extern int nfs_sync_inode(struct inode *inode);
  extern int nfs_wb_all(struct inode *inode);
  extern int nfs_wb_page(struct inode *inode, struct page* page);
  extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);
  extern int  nfs_commit_inode(struct inode *, int);
  extern struct nfs_commit_data *nfs_commitdata_alloc(void);
  extern void nfs_commit_free(struct nfs_commit_data *data);
  
  static inline int
  nfs_have_writebacks(struct inode *inode)
  {
  	return NFS_I(inode)->nrequests != 0;
  }
  
  /*
   * linux/fs/nfs/read.c
   */
  extern int  nfs_readpage(struct file *, struct page *);
  extern int  nfs_readpages(struct file *, struct address_space *,
  		struct list_head *, unsigned);
  extern int  nfs_readpage_async(struct nfs_open_context *, struct inode *,
  			       struct page *);
  
  /*
   * inline functions
   */
  
  static inline loff_t nfs_size_to_loff_t(__u64 size)
  {
  	return min_t(u64, size, OFFSET_MAX);
  }
  
  static inline ino_t
  nfs_fileid_to_ino_t(u64 fileid)
  {
  	ino_t ino = (ino_t) fileid;
  	if (sizeof(ino_t) < sizeof(u64))
  		ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;
  	return ino;
  }
  
  #define NFS_JUKEBOX_RETRY_TIME (5 * HZ)
  
  
  # undef ifdebug
  # ifdef NFS_DEBUG
  #  define ifdebug(fac)		if (unlikely(nfs_debug & NFSDBG_##fac))
  #  define NFS_IFDEBUG(x)	x
  # else
  #  define ifdebug(fac)		if (0)
  #  define NFS_IFDEBUG(x)
  # endif
  #endif