/*
   *  pNFS client data structures.
   *
   *  Copyright (c) 2002
   *  The Regents of the University of Michigan
   *  All Rights Reserved
   *
   *  Dean Hildebrand <dhildebz@umich.edu>
   *
   *  Permission is granted to use, copy, create derivative works, and
   *  redistribute this software and such derivative works for any purpose,
   *  so long as the name of the University of Michigan is not used in
   *  any advertising or publicity pertaining to the use or distribution
   *  of this software without specific, written prior authorization. If
   *  the above copyright notice or any other identification of the
   *  University of Michigan is included in any copy of any portion of
   *  this software, then the disclaimer below must also be included.
   *
   *  This software is provided as is, without representation or warranty
   *  of any kind either express or implied, including without limitation
   *  the implied warranties of merchantability, fitness for a particular
   *  purpose, or noninfringement.  The Regents of the University of
   *  Michigan shall not be liable for any damages, including special,
   *  indirect, incidental, or consequential damages, with respect to any
   *  claim arising out of or in connection with the use of the software,
   *  even if it has been or is hereafter advised of the possibility of
   *  such damages.
   */
  
  #ifndef FS_NFS_PNFS_H
  #define FS_NFS_PNFS_H
  
  #include <linux/nfs_fs.h>
  #include <linux/nfs_page.h>
  
  enum {
  	NFS_LSEG_VALID = 0,	/* cleared when lseg is recalled/returned */
  	NFS_LSEG_ROC,		/* roc bit received from server */
  	NFS_LSEG_LAYOUTCOMMIT,	/* layoutcommit bit set for layoutcommit */
  };
  
  struct pnfs_layout_segment {
  	struct list_head pls_list;
  	struct list_head pls_lc_list;
  	struct pnfs_layout_range pls_range;
  	atomic_t pls_refcount;
  	unsigned long pls_flags;
  	struct pnfs_layout_hdr *pls_layout;
  };
  
  enum pnfs_try_status {
  	PNFS_ATTEMPTED     = 0,
  	PNFS_NOT_ATTEMPTED = 1,
  };
  
  #ifdef CONFIG_NFS_V4_1
  
  #define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
  
  enum {
  	NFS_LAYOUT_RO_FAILED = 0,	/* get ro layout failed stop trying */
  	NFS_LAYOUT_RW_FAILED,		/* get rw layout failed stop trying */
  	NFS_LAYOUT_BULK_RECALL,		/* bulk recall affecting layout */
  	NFS_LAYOUT_ROC,			/* some lseg had roc bit set */
  	NFS_LAYOUT_RETURN,		/* Return this layout ASAP */
  };
  
  enum layoutdriver_policy_flags {
  	/* Should the pNFS client commit and return the layout upon a setattr */
  	PNFS_LAYOUTRET_ON_SETATTR	= 1 << 0,
  	PNFS_LAYOUTRET_ON_ERROR		= 1 << 1,
  };
  
  struct nfs4_deviceid_node;
  
  /* Per-layout driver specific registration structure */
  struct pnfs_layoutdriver_type {
  	struct list_head pnfs_tblid;
  	const u32 id;
  	const char *name;
  	struct module *owner;
  	unsigned flags;
  
  	int (*set_layoutdriver) (struct nfs_server *, const struct nfs_fh *);
  	int (*clear_layoutdriver) (struct nfs_server *);
  
  	struct pnfs_layout_hdr * (*alloc_layout_hdr) (struct inode *inode, gfp_t gfp_flags);
  	void (*free_layout_hdr) (struct pnfs_layout_hdr *);
  
  	struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr, gfp_t gfp_flags);
  	void (*free_lseg) (struct pnfs_layout_segment *lseg);
  
  	/* test for nfs page cache coalescing */
  	const struct nfs_pageio_ops *pg_read_ops;
  	const struct nfs_pageio_ops *pg_write_ops;
  
  	struct pnfs_ds_commit_info *(*get_ds_info) (struct inode *inode);
  	void (*mark_request_commit) (struct nfs_page *req,
  				     struct pnfs_layout_segment *lseg,
  				     struct nfs_commit_info *cinfo);
  	void (*clear_request_commit) (struct nfs_page *req,
  				      struct nfs_commit_info *cinfo);
  	int (*scan_commit_lists) (struct nfs_commit_info *cinfo,
  				  int max);
  	void (*recover_commit_reqs) (struct list_head *list,
  				     struct nfs_commit_info *cinfo);
  	int (*commit_pagelist)(struct inode *inode,
  			       struct list_head *mds_pages,
  			       int how,
  			       struct nfs_commit_info *cinfo);
  
  	/*
  	 * Return PNFS_ATTEMPTED to indicate the layout code has attempted
  	 * I/O, else return PNFS_NOT_ATTEMPTED to fall back to normal NFS
  	 */
  	enum pnfs_try_status (*read_pagelist) (struct nfs_read_data *nfs_data);
  	enum pnfs_try_status (*write_pagelist) (struct nfs_write_data *nfs_data, int how);
  
  	void (*free_deviceid_node) (struct nfs4_deviceid_node *);
  
  	void (*encode_layoutreturn) (struct pnfs_layout_hdr *layoutid,
  				     struct xdr_stream *xdr,
  				     const struct nfs4_layoutreturn_args *args);
  
  	void (*cleanup_layoutcommit) (struct nfs4_layoutcommit_data *data);
  
  	void (*encode_layoutcommit) (struct pnfs_layout_hdr *layoutid,
  				     struct xdr_stream *xdr,
  				     const struct nfs4_layoutcommit_args *args);
  };
  
  struct pnfs_layout_hdr {
  	atomic_t		plh_refcount;
  	struct list_head	plh_layouts;   /* other client layouts */
  	struct list_head	plh_bulk_destroy;
  	struct list_head	plh_segs;      /* layout segments list */
  	nfs4_stateid		plh_stateid;
  	atomic_t		plh_outstanding; /* number of RPCs out */
  	unsigned long		plh_block_lgets; /* block LAYOUTGET if >0 */
  	u32			plh_barrier; /* ignore lower seqids */
  	unsigned long		plh_retry_timestamp;
  	unsigned long		plh_flags;
  	loff_t			plh_lwb; /* last write byte for layoutcommit */
  	struct rpc_cred		*plh_lc_cred; /* layoutcommit cred */
  	struct inode		*plh_inode;
  };
  
  struct pnfs_device {
  	struct nfs4_deviceid dev_id;
  	unsigned int  layout_type;
  	unsigned int  mincount;
  	unsigned int  maxcount;	/* gdia_maxcount */
  	struct page **pages;
  	unsigned int  pgbase;
  	unsigned int  pglen;	/* reply buffer length */
  };
  
  #define NFS4_PNFS_GETDEVLIST_MAXNUM 16
  
  struct pnfs_devicelist {
  	unsigned int		eof;
  	unsigned int		num_devs;
  	struct nfs4_deviceid	dev_id[NFS4_PNFS_GETDEVLIST_MAXNUM];
  };
  
  extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
  extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
  
  /* nfs4proc.c */
  extern int nfs4_proc_getdevicelist(struct nfs_server *server,
  				   const struct nfs_fh *fh,
  				   struct pnfs_devicelist *devlist);
  extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
  				   struct pnfs_device *dev,
  				   struct rpc_cred *cred);
  extern struct pnfs_layout_segment* nfs4_proc_layoutget(struct nfs4_layoutget *lgp, gfp_t gfp_flags);
  extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp);
  
  /* pnfs.c */
  void pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo);
  void pnfs_put_lseg(struct pnfs_layout_segment *lseg);
  
  void pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *,
  			   const struct nfs_pgio_completion_ops *);
  void pnfs_pageio_init_write(struct nfs_pageio_descriptor *, struct inode *,
  			    int, const struct nfs_pgio_completion_ops *);
  
  void set_pnfs_layoutdriver(struct nfs_server *, const struct nfs_fh *, u32);
  void unset_pnfs_layoutdriver(struct nfs_server *);
  void pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *, struct nfs_page *);
  int pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc);
  void pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
  			        struct nfs_page *req, u64 wb_size);
  int pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc);
  bool pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, struct nfs_page *req);
  void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg);
  struct pnfs_layout_segment *pnfs_layout_process(struct nfs4_layoutget *lgp);
  void pnfs_free_lseg_list(struct list_head *tmp_list);
  void pnfs_destroy_layout(struct nfs_inode *);
  void pnfs_destroy_all_layouts(struct nfs_client *);
  int pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
  		struct nfs_fsid *fsid,
  		bool is_recall);
  int pnfs_destroy_layouts_byclid(struct nfs_client *clp,
  		bool is_recall);
  void pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo);
  void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
  			     const nfs4_stateid *new,
  			     bool update_barrier);
  int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
  				  struct pnfs_layout_hdr *lo,
  				  struct nfs4_state *open_state);
  int pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
  				struct list_head *tmp_list,
  				struct pnfs_layout_range *recall_range);
  bool pnfs_roc(struct inode *ino);
  void pnfs_roc_release(struct inode *ino);
  void pnfs_roc_set_barrier(struct inode *ino, u32 barrier);
  bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task);
  void pnfs_set_layoutcommit(struct nfs_write_data *wdata);
  void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data);
  int pnfs_layoutcommit_inode(struct inode *inode, bool sync);
  int _pnfs_return_layout(struct inode *);
  int pnfs_commit_and_return_layout(struct inode *);
  void pnfs_ld_write_done(struct nfs_write_data *);
  void pnfs_ld_read_done(struct nfs_read_data *);
  struct pnfs_layout_segment *pnfs_update_layout(struct inode *ino,
  					       struct nfs_open_context *ctx,
  					       loff_t pos,
  					       u64 count,
  					       enum pnfs_iomode iomode,
  					       gfp_t gfp_flags);
  
  void nfs4_deviceid_mark_client_invalid(struct nfs_client *clp);
  int pnfs_read_done_resend_to_mds(struct inode *inode, struct list_head *head,
  			const struct nfs_pgio_completion_ops *compl_ops,
  			struct nfs_direct_req *dreq);
  int pnfs_write_done_resend_to_mds(struct inode *inode, struct list_head *head,
  			const struct nfs_pgio_completion_ops *compl_ops,
  			struct nfs_direct_req *dreq);
  struct nfs4_threshold *pnfs_mdsthreshold_alloc(void);
  
  /* nfs4_deviceid_flags */
  enum {
  	NFS_DEVICEID_INVALID = 0,       /* set when MDS clientid recalled */
  	NFS_DEVICEID_UNAVAILABLE,	/* device temporarily unavailable */
  };
  
  /* pnfs_dev.c */
  struct nfs4_deviceid_node {
  	struct hlist_node		node;
  	struct hlist_node		tmpnode;
  	const struct pnfs_layoutdriver_type *ld;
  	const struct nfs_client		*nfs_client;
  	unsigned long 			flags;
  	unsigned long			timestamp_unavailable;
  	struct nfs4_deviceid		deviceid;
  	atomic_t			ref;
  };
  
  struct nfs4_deviceid_node *nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *);
  void nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *);
  void nfs4_init_deviceid_node(struct nfs4_deviceid_node *,
  			     const struct pnfs_layoutdriver_type *,
  			     const struct nfs_client *,
  			     const struct nfs4_deviceid *);
  struct nfs4_deviceid_node *nfs4_insert_deviceid_node(struct nfs4_deviceid_node *);
  bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *);
  void nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node);
  bool nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node);
  void nfs4_deviceid_purge_client(const struct nfs_client *);
  
  static inline struct pnfs_layout_segment *
  pnfs_get_lseg(struct pnfs_layout_segment *lseg)
  {
  	if (lseg) {
  		atomic_inc(&lseg->pls_refcount);
  		smp_mb__after_atomic_inc();
  	}
  	return lseg;
  }
  
  /* Return true if a layout driver is being used for this mountpoint */
  static inline int pnfs_enabled_sb(struct nfs_server *nfss)
  {
  	return nfss->pnfs_curr_ld != NULL;
  }
  
  static inline int
  pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how,
  		 struct nfs_commit_info *cinfo)
  {
  	if (cinfo->ds == NULL || cinfo->ds->ncommitting == 0)
  		return PNFS_NOT_ATTEMPTED;
  	return NFS_SERVER(inode)->pnfs_curr_ld->commit_pagelist(inode, mds_pages, how, cinfo);
  }
  
  static inline struct pnfs_ds_commit_info *
  pnfs_get_ds_info(struct inode *inode)
  {
  	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
  
  	if (ld == NULL || ld->get_ds_info == NULL)
  		return NULL;
  	return ld->get_ds_info(inode);
  }
  
  static inline bool
  pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
  			 struct nfs_commit_info *cinfo)
  {
  	struct inode *inode = req->wb_context->dentry->d_inode;
  	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
  
  	if (lseg == NULL || ld->mark_request_commit == NULL)
  		return false;
  	ld->mark_request_commit(req, lseg, cinfo);
  	return true;
  }
  
  static inline bool
  pnfs_clear_request_commit(struct nfs_page *req, struct nfs_commit_info *cinfo)
  {
  	struct inode *inode = req->wb_context->dentry->d_inode;
  	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
  
  	if (ld == NULL || ld->clear_request_commit == NULL)
  		return false;
  	ld->clear_request_commit(req, cinfo);
  	return true;
  }
  
  static inline int
  pnfs_scan_commit_lists(struct inode *inode, struct nfs_commit_info *cinfo,
  		       int max)
  {
  	if (cinfo->ds == NULL || cinfo->ds->nwritten == 0)
  		return 0;
  	else
  		return NFS_SERVER(inode)->pnfs_curr_ld->scan_commit_lists(cinfo, max);
  }
  
  static inline void
  pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
  			 struct nfs_commit_info *cinfo)
  {
  	if (cinfo->ds == NULL || cinfo->ds->nwritten == 0)
  		return;
  	NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo);
  }
  
  /* Should the pNFS client commit and return the layout upon a setattr */
  static inline bool
  pnfs_ld_layoutret_on_setattr(struct inode *inode)
  {
  	if (!pnfs_enabled_sb(NFS_SERVER(inode)))
  		return false;
  	return NFS_SERVER(inode)->pnfs_curr_ld->flags &
  		PNFS_LAYOUTRET_ON_SETATTR;
  }
  
  static inline bool
  pnfs_layoutcommit_outstanding(struct inode *inode)
  {
  	struct nfs_inode *nfsi = NFS_I(inode);
  
  	return test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags) != 0 ||
  		test_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags) != 0;
  }
  
  static inline int pnfs_return_layout(struct inode *ino)
  {
  	struct nfs_inode *nfsi = NFS_I(ino);
  	struct nfs_server *nfss = NFS_SERVER(ino);
  
  	if (pnfs_enabled_sb(nfss) && nfsi->layout)
  		return _pnfs_return_layout(ino);
  
  	return 0;
  }
  
  static inline bool
  pnfs_use_threshold(struct nfs4_threshold **dst, struct nfs4_threshold *src,
  		   struct nfs_server *nfss)
  {
  	return (dst && src && src->bm != 0 && nfss->pnfs_curr_ld &&
  					nfss->pnfs_curr_ld->id == src->l_type);
  }
  
  #ifdef NFS_DEBUG
  void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id);
  #else
  static inline void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id)
  {
  }
  #endif /* NFS_DEBUG */
  #else  /* CONFIG_NFS_V4_1 */
  
  static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
  {
  }
  
  static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
  {
  }
  
  static inline struct pnfs_layout_segment *
  pnfs_get_lseg(struct pnfs_layout_segment *lseg)
  {
  	return NULL;
  }
  
  static inline void pnfs_put_lseg(struct pnfs_layout_segment *lseg)
  {
  }
  
  static inline int pnfs_return_layout(struct inode *ino)
  {
  	return 0;
  }
  
  static inline int pnfs_commit_and_return_layout(struct inode *inode)
  {
  	return 0;
  }
  
  static inline bool
  pnfs_ld_layoutret_on_setattr(struct inode *inode)
  {
  	return false;
  }
  
  static inline bool
  pnfs_roc(struct inode *ino)
  {
  	return false;
  }
  
  static inline void
  pnfs_roc_release(struct inode *ino)
  {
  }
  
  static inline void
  pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
  {
  }
  
  static inline bool
  pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
  {
  	return false;
  }
  
  static inline void set_pnfs_layoutdriver(struct nfs_server *s,
  					 const struct nfs_fh *mntfh, u32 id)
  {
  }
  
  static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
  {
  }
  
  static inline void pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode,
  					 const struct nfs_pgio_completion_ops *compl_ops)
  {
  	nfs_pageio_init_read(pgio, inode, compl_ops);
  }
  
  static inline void pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode, int ioflags,
  					  const struct nfs_pgio_completion_ops *compl_ops)
  {
  	nfs_pageio_init_write(pgio, inode, ioflags, compl_ops);
  }
  
  static inline int
  pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how,
  		 struct nfs_commit_info *cinfo)
  {
  	return PNFS_NOT_ATTEMPTED;
  }
  
  static inline struct pnfs_ds_commit_info *
  pnfs_get_ds_info(struct inode *inode)
  {
  	return NULL;
  }
  
  static inline bool
  pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
  			 struct nfs_commit_info *cinfo)
  {
  	return false;
  }
  
  static inline bool
  pnfs_clear_request_commit(struct nfs_page *req, struct nfs_commit_info *cinfo)
  {
  	return false;
  }
  
  static inline int
  pnfs_scan_commit_lists(struct inode *inode, struct nfs_commit_info *cinfo,
  		       int max)
  {
  	return 0;
  }
  
  static inline void
  pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
  			 struct nfs_commit_info *cinfo)
  {
  }
  
  static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)
  {
  	return 0;
  }
  
  static inline bool
  pnfs_use_threshold(struct nfs4_threshold **dst, struct nfs4_threshold *src,
  		   struct nfs_server *nfss)
  {
  	return false;
  }
  
  static inline bool
  pnfs_layoutcommit_outstanding(struct inode *inode)
  {
  	return false;
  }
  
  
  static inline struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
  {
  	return NULL;
  }
  
  #endif /* CONFIG_NFS_V4_1 */
  
  #endif /* FS_NFS_PNFS_H */