/*
   *  Data types and function declerations for interfacing with the
   *  pNFS standard object layout driver.
   *
   *  Copyright (C) 2007 Panasas Inc. [year of first publication]
   *  All rights reserved.
   *
   *  Benny Halevy <bhalevy@panasas.com>
   *  Boaz Harrosh <bharrosh@panasas.com>
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License version 2
   *  See the file COPYING included with this distribution for more details.
   *
   *  Redistribution and use in source and binary forms, with or without
   *  modification, are permitted provided that the following conditions
   *  are met:
   *
   *  1. Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the following disclaimer.
   *  2. Redistributions in binary form must reproduce the above copyright
   *     notice, this list of conditions and the following disclaimer in the
   *     documentation and/or other materials provided with the distribution.
   *  3. Neither the name of the Panasas company nor the names of its
   *     contributors may be used to endorse or promote products derived
   *     from this software without specific prior written permission.
   *
   *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
   *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
   *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifndef _OBJLAYOUT_H
  #define _OBJLAYOUT_H
  
  #include <linux/nfs_fs.h>
  #include <linux/pnfs_osd_xdr.h>
  #include "../pnfs.h"
  
  /*
   * per-inode layout
   */
  struct objlayout {
  	struct pnfs_layout_hdr pnfs_layout;
  
  	 /* for layout_commit */
  	enum osd_delta_space_valid_enum {
  		OBJ_DSU_INIT = 0,
  		OBJ_DSU_VALID,
  		OBJ_DSU_INVALID,
  	} delta_space_valid;
  	s64 delta_space_used;  /* consumed by write ops */
  
  	 /* for layout_return */
  	spinlock_t lock;
  	struct list_head err_list;
  };
  
  static inline struct objlayout *
  OBJLAYOUT(struct pnfs_layout_hdr *lo)
  {
  	return container_of(lo, struct objlayout, pnfs_layout);
  }
  
  /*
   * per-I/O operation state
   * embedded in objects provider io_state data structure
   */
  struct objlayout_io_res {
  	struct objlayout *objlay;
  
  	void *rpcdata;
  	int status;             /* res */
  	int committed;          /* res */
  
  	/* Error reporting (layout_return) */
  	struct list_head err_list;
  	unsigned num_comps;
  	/* Pointer to array of error descriptors of size num_comps.
  	 * It should contain as many entries as devices in the osd_layout
  	 * that participate in the I/O. It is up to the io_engine to allocate
  	 * needed space and set num_comps.
  	 */
  	struct pnfs_osd_ioerr *ioerrs;
  };
  
  static inline
  void objlayout_init_ioerrs(struct objlayout_io_res *oir, unsigned num_comps,
  			struct pnfs_osd_ioerr *ioerrs, void *rpcdata,
  			struct pnfs_layout_hdr *pnfs_layout_type)
  {
  	oir->objlay = OBJLAYOUT(pnfs_layout_type);
  	oir->rpcdata = rpcdata;
  	INIT_LIST_HEAD(&oir->err_list);
  	oir->num_comps = num_comps;
  	oir->ioerrs = ioerrs;
  }
  
  /*
   * Raid engine I/O API
   */
  extern int objio_alloc_lseg(struct pnfs_layout_segment **outp,
  	struct pnfs_layout_hdr *pnfslay,
  	struct pnfs_layout_range *range,
  	struct xdr_stream *xdr,
  	gfp_t gfp_flags);
  extern void objio_free_lseg(struct pnfs_layout_segment *lseg);
  
  /* objio_free_result will free these @oir structs received from
   * objlayout_{read,write}_done
   */
  extern void objio_free_result(struct objlayout_io_res *oir);
  
  extern int objio_read_pagelist(struct nfs_read_data *rdata);
  extern int objio_write_pagelist(struct nfs_write_data *wdata, int how);
  
  /*
   * callback API
   */
  extern void objlayout_io_set_result(struct objlayout_io_res *oir,
  			unsigned index, struct pnfs_osd_objid *pooid,
  			int osd_error, u64 offset, u64 length, bool is_write);
  
  static inline void
  objlayout_add_delta_space_used(struct objlayout *objlay, s64 space_used)
  {
  	/* If one of the I/Os errored out and the delta_space_used was
  	 * invalid we render the complete report as invalid. Protocol mandate
  	 * the DSU be accurate or not reported.
  	 */
  	spin_lock(&objlay->lock);
  	if (objlay->delta_space_valid != OBJ_DSU_INVALID) {
  		objlay->delta_space_valid = OBJ_DSU_VALID;
  		objlay->delta_space_used += space_used;
  	}
  	spin_unlock(&objlay->lock);
  }
  
  extern void objlayout_read_done(struct objlayout_io_res *oir,
  				ssize_t status, bool sync);
  extern void objlayout_write_done(struct objlayout_io_res *oir,
  				 ssize_t status, bool sync);
  
  extern int objlayout_get_deviceinfo(struct pnfs_layout_hdr *pnfslay,
  	struct nfs4_deviceid *d_id, struct pnfs_osd_deviceaddr **deviceaddr,
  	gfp_t gfp_flags);
  extern void objlayout_put_deviceinfo(struct pnfs_osd_deviceaddr *deviceaddr);
  
  /*
   * exported generic objects function vectors
   */
  
  extern struct pnfs_layout_hdr *objlayout_alloc_layout_hdr(struct inode *, gfp_t gfp_flags);
  extern void objlayout_free_layout_hdr(struct pnfs_layout_hdr *);
  
  extern struct pnfs_layout_segment *objlayout_alloc_lseg(
  	struct pnfs_layout_hdr *,
  	struct nfs4_layoutget_res *,
  	gfp_t gfp_flags);
  extern void objlayout_free_lseg(struct pnfs_layout_segment *);
  
  extern enum pnfs_try_status objlayout_read_pagelist(
  	struct nfs_read_data *);
  
  extern enum pnfs_try_status objlayout_write_pagelist(
  	struct nfs_write_data *,
  	int how);
  
  extern void objlayout_encode_layoutcommit(
  	struct pnfs_layout_hdr *,
  	struct xdr_stream *,
  	const struct nfs4_layoutcommit_args *);
  
  extern void objlayout_encode_layoutreturn(
  	struct pnfs_layout_hdr *,
  	struct xdr_stream *,
  	const struct nfs4_layoutreturn_args *);
  
  extern int objlayout_autologin(struct pnfs_osd_deviceaddr *deviceaddr);
  
  #endif /* _OBJLAYOUT_H */