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 <bharrosh@panasas.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_state {
 78	struct pnfs_layout_segment *lseg;
 79
 80	struct page **pages;
 81	unsigned pgbase;
 82	unsigned nr_pages;
 83	unsigned long count;
 84	loff_t offset;
 85	bool sync;
 86
 87	void *rpcdata;
 88	int status;             /* res */
 89	int eof;                /* res */
 90	int committed;          /* res */
 91
 92	/* Error reporting (layout_return) */
 93	struct list_head err_list;
 94	unsigned num_comps;
 95	/* Pointer to array of error descriptors of size num_comps.
 96	 * It should contain as many entries as devices in the osd_layout
 97	 * that participate in the I/O. It is up to the io_engine to allocate
 98	 * needed space and set num_comps.
 99	 */
100	struct pnfs_osd_ioerr *ioerrs;
101};
102
103/*
104 * Raid engine I/O API
105 */
106extern int objio_alloc_lseg(struct pnfs_layout_segment **outp,
107	struct pnfs_layout_hdr *pnfslay,
108	struct pnfs_layout_range *range,
109	struct xdr_stream *xdr,
110	gfp_t gfp_flags);
111extern void objio_free_lseg(struct pnfs_layout_segment *lseg);
112
113extern int objio_alloc_io_state(
114	struct pnfs_layout_segment *lseg,
115	struct objlayout_io_state **outp,
116	gfp_t gfp_flags);
117extern void objio_free_io_state(struct objlayout_io_state *state);
118
119extern ssize_t objio_read_pagelist(struct objlayout_io_state *ol_state);
120extern ssize_t objio_write_pagelist(struct objlayout_io_state *ol_state,
121				    bool stable);
122
123/*
124 * callback API
125 */
126extern void objlayout_io_set_result(struct objlayout_io_state *state,
127			unsigned index, struct pnfs_osd_objid *pooid,
128			int osd_error, u64 offset, u64 length, bool is_write);
129
130static inline void
131objlayout_add_delta_space_used(struct objlayout_io_state *state, s64 space_used)
132{
133	struct objlayout *objlay = OBJLAYOUT(state->lseg->pls_layout);
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_state *state,
148				ssize_t status, bool sync);
149extern void objlayout_write_done(struct objlayout_io_state *state,
150				 ssize_t status, bool sync);
151
152extern int objlayout_get_deviceinfo(struct pnfs_layout_hdr *pnfslay,
153	struct nfs4_deviceid *d_id, struct pnfs_osd_deviceaddr **deviceaddr,
154	gfp_t gfp_flags);
155extern void objlayout_put_deviceinfo(struct pnfs_osd_deviceaddr *deviceaddr);
156
157/*
158 * exported generic objects function vectors
159 */
160
161extern struct pnfs_layout_hdr *objlayout_alloc_layout_hdr(struct inode *, gfp_t gfp_flags);
162extern void objlayout_free_layout_hdr(struct pnfs_layout_hdr *);
163
164extern struct pnfs_layout_segment *objlayout_alloc_lseg(
165	struct pnfs_layout_hdr *,
166	struct nfs4_layoutget_res *,
167	gfp_t gfp_flags);
168extern void objlayout_free_lseg(struct pnfs_layout_segment *);
169
170extern enum pnfs_try_status objlayout_read_pagelist(
171	struct nfs_read_data *);
172
173extern enum pnfs_try_status objlayout_write_pagelist(
174	struct nfs_write_data *,
175	int how);
176
177extern void objlayout_encode_layoutcommit(
178	struct pnfs_layout_hdr *,
179	struct xdr_stream *,
180	const struct nfs4_layoutcommit_args *);
181
182extern void objlayout_encode_layoutreturn(
183	struct pnfs_layout_hdr *,
184	struct xdr_stream *,
185	const struct nfs4_layoutreturn_args *);
186
187#endif /* _OBJLAYOUT_H */