/*
   * linux/fs/nfs/delegation.h
   *
   * Copyright (c) Trond Myklebust
   *
   * Definitions pertaining to NFS delegated files
   */
  #ifndef FS_NFS_DELEGATION_H
  #define FS_NFS_DELEGATION_H

  #if IS_ENABLED(CONFIG_NFS_V4)

  /*
   * NFSv4 delegation
   */
  struct nfs_delegation {
  	struct list_head super_list;
  	struct rpc_cred *cred;
  	struct inode *inode;
  	nfs4_stateid stateid;

  	fmode_t type;

  	unsigned long pagemod_limit;

  	__u64 change_attr;

  	unsigned long flags;

  	spinlock_t lock;

  	struct rcu_head rcu;

  };

  enum {
  	NFS_DELEGATION_NEED_RECLAIM = 0,
  	NFS_DELEGATION_RETURN,

  	NFS_DELEGATION_RETURN_IF_CLOSED,

  	NFS_DELEGATION_REFERENCED,

  	NFS_DELEGATION_RETURNING,

  	NFS_DELEGATION_REVOKED,

  };

  int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res);
  void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res);

  int nfs4_inode_return_delegation(struct inode *inode);

  int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid);

  void nfs_inode_return_delegation_noreclaim(struct inode *inode);

  struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs_fh *fhandle);

  void nfs_server_return_all_delegations(struct nfs_server *);

  void nfs_expire_all_delegations(struct nfs_client *clp);

  void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags);

  void nfs_expire_unreferenced_delegations(struct nfs_client *clp);

  int nfs_client_return_marked_delegations(struct nfs_client *clp);

  int nfs_delegations_present(struct nfs_client *clp);

  void nfs_remove_bad_delegation(struct inode *inode);

  void nfs_delegation_mark_reclaim(struct nfs_client *clp);
  void nfs_delegation_reap_unclaimed(struct nfs_client *clp);

  
  /* NFSv4 delegation-related procedures */

  int nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid, int issync);

  int nfs4_open_delegation_recall(struct nfs_open_context *ctx, struct nfs4_state *state, const nfs4_stateid *stateid, fmode_t type);

  int nfs4_lock_delegation_recall(struct file_lock *fl, struct nfs4_state *state, const nfs4_stateid *stateid);

  bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode, fmode_t flags);

  void nfs_mark_delegation_referenced(struct nfs_delegation *delegation);

  int nfs4_have_delegation(struct inode *inode, fmode_t flags);

  int nfs4_check_delegation(struct inode *inode, fmode_t flags);

  bool nfs4_delegation_flush_on_close(const struct inode *inode);

  #endif

  static inline int nfs_have_delegated_attributes(struct inode *inode)
  {

  	return NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) &&

  		!(NFS_I(inode)->cache_validity & NFS_INO_REVAL_FORCED);
  }

  #endif