/*
   *  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_DESTROYED,		/* no new use of layout allowed */

  };

  enum layoutdriver_policy_flags {
  	/* Should the pNFS client commit and return the layout upon a setattr */
  	PNFS_LAYOUTRET_ON_SETATTR	= 1 << 0,
  };

  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;

  	/* Returns true if layoutdriver wants to divert this request to
  	 * driver's commit routine.
  	 */
  	bool (*mark_pnfs_commit)(struct pnfs_layout_segment *lseg);
  	struct list_head * (*choose_commit_list) (struct nfs_page *req);
  	int (*commit_pagelist)(struct inode *inode, struct list_head *mds_pages, int how);

  	/*
  	 * 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_recall; /* clnt list of bulk recalls */

  	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_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;
  	struct page **pages;

  	unsigned int  pgbase;
  	unsigned int  pglen;
  };

  #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);
  extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);

  extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp);

  
  /* pnfs.c */

  void get_layout_hdr(struct pnfs_layout_hdr *lo);

  void put_lseg(struct pnfs_layout_segment *lseg);

  
  bool pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *);
  bool pnfs_pageio_init_write(struct nfs_pageio_descriptor *, struct inode *, int);

  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 *, struct nfs_page *);

  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);

  int 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 *);

  void 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 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);

  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 *);

  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);
  
  /* nfs4_deviceid_flags */
  enum {
  	NFS_DEVICEID_INVALID = 0,       /* set when MDS clientid recalled */
  };

  /* 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;

  	struct nfs4_deviceid		deviceid;
  	atomic_t			ref;
  };
  
  void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id);

  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_deviceid_purge_client(const struct nfs_client *);

  static inline int lo_fail_bit(u32 iomode)
  {
  	return iomode == IOMODE_RW ?
  			 NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
  }

  static inline struct pnfs_layout_segment *
  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 void
  pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
  {
  	if (lseg) {
  		struct pnfs_layoutdriver_type *ld;
  
  		ld = NFS_SERVER(req->wb_page->mapping->host)->pnfs_curr_ld;
  		if (ld->mark_pnfs_commit && ld->mark_pnfs_commit(lseg)) {
  			set_bit(PG_PNFS_COMMIT, &req->wb_flags);
  			req->wb_commit_lseg = get_lseg(lseg);
  		}
  	}
  }
  
  static inline int
  pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how)
  {
  	if (!test_and_clear_bit(NFS_INO_PNFS_COMMIT, &NFS_I(inode)->flags))
  		return PNFS_NOT_ATTEMPTED;
  	return NFS_SERVER(inode)->pnfs_curr_ld->commit_pagelist(inode, mds_pages, how);
  }
  
  static inline struct list_head *
  pnfs_choose_commit_list(struct nfs_page *req, struct list_head *mds)
  {
  	struct list_head *rv;
  
  	if (test_and_clear_bit(PG_PNFS_COMMIT, &req->wb_flags)) {
  		struct inode *inode = req->wb_commit_lseg->pls_layout->plh_inode;
  
  		set_bit(NFS_INO_PNFS_COMMIT, &NFS_I(inode)->flags);
  		rv = NFS_SERVER(inode)->pnfs_curr_ld->choose_commit_list(req);
  		/* matched by ref taken when PG_PNFS_COMMIT is set */
  		put_lseg(req->wb_commit_lseg);
  	} else
  		rv = mds;
  	return rv;
  }
  
  static inline void pnfs_clear_request_commit(struct nfs_page *req)
  {
  	if (test_and_clear_bit(PG_PNFS_COMMIT, &req->wb_flags))
  		put_lseg(req->wb_commit_lseg);
  }

  /* 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 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;
  }

  #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 *

  get_lseg(struct pnfs_layout_segment *lseg)
  {
  	return NULL;
  }
  
  static inline void put_lseg(struct pnfs_layout_segment *lseg)
  {
  }

  static inline int pnfs_return_layout(struct inode *ino)
  {
  	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)
  {
  	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 bool pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode)

  {

  	return false;
  }
  
  static inline bool pnfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode, int ioflags)
  {
  	return false;

  }

  static inline void
  pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
  {
  }
  
  static inline int
  pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how)
  {
  	return PNFS_NOT_ATTEMPTED;
  }
  
  static inline struct list_head *
  pnfs_choose_commit_list(struct nfs_page *req, struct list_head *mds)
  {
  	return mds;
  }
  
  static inline void pnfs_clear_request_commit(struct nfs_page *req)
  {
  }

  static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)

  {
  	return 0;
  }

  
  static inline void nfs4_deviceid_purge_client(struct nfs_client *ncl)
  {
  }

  #endif /* CONFIG_NFS_V4_1 */
  
  #endif /* FS_NFS_PNFS_H */