1/*
  2 *  Data types and function declerations for interfacing with the
  3 *  pNFS standard object layout driver.
  4 *
  5 *  Copyright (C) 2007 Panasas Inc. [year of first publication]
  6 *  All rights reserved.
  7 *
  8 *  Benny Halevy <bhalevy@panasas.com>
  9 *  Boaz Harrosh <ooo@electrozaur.com>
 10 *
 11 *  This program is free software; you can redistribute it and/or modify
 12 *  it under the terms of the GNU General Public License version 2
 13 *  See the file COPYING included with this distribution for more details.
 14 *
 15 *  Redistribution and use in source and binary forms, with or without
 16 *  modification, are permitted provided that the following conditions
 17 *  are met:
 18 *
 19 *  1. Redistributions of source code must retain the above copyright
 20 *     notice, this list of conditions and the following disclaimer.
 21 *  2. Redistributions in binary form must reproduce the above copyright
 22 *     notice, this list of conditions and the following disclaimer in the
 23 *     documentation and/or other materials provided with the distribution.
 24 *  3. Neither the name of the Panasas company nor the names of its
 25 *     contributors may be used to endorse or promote products derived
 26 *     from this software without specific prior written permission.
 27 *
 28 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 29 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 30 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 31 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 32 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 33 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 34 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 35 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 36 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 37 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 38 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 39 */
 40
 41#ifndef _OBJLAYOUT_H
 42#define _OBJLAYOUT_H
 43
 44#include <linux/nfs_fs.h>
 45#include <linux/pnfs_osd_xdr.h>
 46#include "../pnfs.h"
 47
 48/*
 49 * per-inode layout
 50 */
 51struct objlayout {
 52	struct pnfs_layout_hdr pnfs_layout;
 53
 54	 /* for layout_commit */
 55	enum osd_delta_space_valid_enum {
 56		OBJ_DSU_INIT = 0,
 57		OBJ_DSU_VALID,
 58		OBJ_DSU_INVALID,
 59	} delta_space_valid;
 60	s64 delta_space_used;  /* consumed by write ops */
 61
 62	 /* for layout_return */
 63	spinlock_t lock;
 64	struct list_head err_list;
 65};
 66
 67static inline struct objlayout *
 68OBJLAYOUT(struct pnfs_layout_hdr *lo)
 69{
 70	return container_of(lo, struct objlayout, pnfs_layout);
 71}
 72
 73/*
 74 * per-I/O operation state
 75 * embedded in objects provider io_state data structure
 76 */
 77struct objlayout_io_res {
 78	struct objlayout *objlay;
 79
 80	void *rpcdata;
 81	int status;             /* res */
 82	int committed;          /* res */
 83
 84	/* Error reporting (layout_return) */
 85	struct list_head err_list;
 86	unsigned num_comps;
 87	/* Pointer to array of error descriptors of size num_comps.
 88	 * It should contain as many entries as devices in the osd_layout
 89	 * that participate in the I/O. It is up to the io_engine to allocate
 90	 * needed space and set num_comps.
 91	 */
 92	struct pnfs_osd_ioerr *ioerrs;
 93};
 94
 95static inline
 96void objlayout_init_ioerrs(struct objlayout_io_res *oir, unsigned num_comps,
 97			struct pnfs_osd_ioerr *ioerrs, void *rpcdata,
 98			struct pnfs_layout_hdr *pnfs_layout_type)
 99{
100	oir->objlay = OBJLAYOUT(pnfs_layout_type);
101	oir->rpcdata = rpcdata;
102	INIT_LIST_HEAD(&oir->err_list);
103	oir->num_comps = num_comps;
104	oir->ioerrs = ioerrs;
105}
106
107/*
108 * Raid engine I/O API
109 */
110extern int objio_alloc_lseg(struct pnfs_layout_segment **outp,
111	struct pnfs_layout_hdr *pnfslay,
112	struct pnfs_layout_range *range,
113	struct xdr_stream *xdr,
114	gfp_t gfp_flags);
115extern void objio_free_lseg(struct pnfs_layout_segment *lseg);
116
117/* objio_free_result will free these @oir structs received from
118 * objlayout_{read,write}_done
119 */
120extern void objio_free_result(struct objlayout_io_res *oir);
121
122extern int objio_read_pagelist(struct nfs_pgio_header *rdata);
123extern int objio_write_pagelist(struct nfs_pgio_header *wdata, int how);
124
125/*
126 * callback API
127 */
128extern void objlayout_io_set_result(struct objlayout_io_res *oir,
129			unsigned index, struct pnfs_osd_objid *pooid,
130			int osd_error, u64 offset, u64 length, bool is_write);
131
132static inline void
133objlayout_add_delta_space_used(struct objlayout *objlay, s64 space_used)
134{
135	/* If one of the I/Os errored out and the delta_space_used was
136	 * invalid we render the complete report as invalid. Protocol mandate
137	 * the DSU be accurate or not reported.
138	 */
139	spin_lock(&objlay->lock);
140	if (objlay->delta_space_valid != OBJ_DSU_INVALID) {
141		objlay->delta_space_valid = OBJ_DSU_VALID;
142		objlay->delta_space_used += space_used;
143	}
144	spin_unlock(&objlay->lock);
145}
146
147extern void objlayout_read_done(struct objlayout_io_res *oir,
148				ssize_t status, bool sync);
149extern void objlayout_write_done(struct objlayout_io_res *oir,
150				 ssize_t status, bool sync);
151
152/*
153 * exported generic objects function vectors
154 */
155
156extern struct pnfs_layout_hdr *objlayout_alloc_layout_hdr(struct inode *, gfp_t gfp_flags);
157extern void objlayout_free_layout_hdr(struct pnfs_layout_hdr *);
158
159extern struct pnfs_layout_segment *objlayout_alloc_lseg(
160	struct pnfs_layout_hdr *,
161	struct nfs4_layoutget_res *,
162	gfp_t gfp_flags);
163extern void objlayout_free_lseg(struct pnfs_layout_segment *);
164
165extern enum pnfs_try_status objlayout_read_pagelist(
166	struct nfs_pgio_header *);
167
168extern enum pnfs_try_status objlayout_write_pagelist(
169	struct nfs_pgio_header *,
170	int how);
171
172extern void objlayout_encode_layoutcommit(
173	struct pnfs_layout_hdr *,
174	struct xdr_stream *,
175	const struct nfs4_layoutcommit_args *);
176
177extern void objlayout_encode_layoutreturn(
178	struct pnfs_layout_hdr *,
179	struct xdr_stream *,
180	const struct nfs4_layoutreturn_args *);
181
182extern int objlayout_autologin(struct pnfs_osd_deviceaddr *deviceaddr);
183
184#endif /* _OBJLAYOUT_H */