geom_vinum_raid5.h revision 139778 
1/*-
2 * Copyright (c) 2004 Lukas Ertl
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: head/sys/geom/vinum/geom_vinum_raid5.h 139778 2005-01-06 18:27:30Z imp $
27 */
28
29#ifndef _GEOM_VINUM_RAID5_H_
30#define	_GEOM_VINUM_RAID5_H_
31
32/*
33 * A single RAID5 request usually needs more than one I/O transaction,
34 * depending on the state of the associated subdisks and the direction of the
35 * transaction (read or write).
36 */
37
38#define	GV_ENQUEUE(bp, cbp, pbp)				\
39	do { 							\
40		if (bp->bio_driver1 == NULL) {			\
41			bp->bio_driver1 = cbp;			\
42		} else {					\
43			pbp = bp->bio_driver1;			\
44			while (pbp->bio_caller1 != NULL)	\
45				pbp = pbp->bio_caller1;		\
46			pbp->bio_caller1 = cbp;			\
47		}						\
48	} while (0);
49
50struct gv_raid5_packet {
51	caddr_t	data;		/* Data buffer of this sub-request- */
52	off_t	length;		/* Size of data buffer. */
53	off_t	lockbase;	/* Deny access to our plex offset. */
54	off_t	offset;		/* The drive offset of the subdisk. */
55	int	bufmalloc;	/* Flag if data buffer was malloced. */
56	int	active;		/* Count of active subrequests. */
57	int	rqcount;	/* Count of subrequests. */
58
59	struct bio	*bio;	/* Pointer to the original bio. */
60	struct bio	*parity;  /* The bio containing the parity data. */
61	struct bio	*waiting; /* A bio that need to wait for other bios. */
62
63	TAILQ_HEAD(,gv_bioq)		bits; /* List of subrequests. */
64	TAILQ_ENTRY(gv_raid5_packet)	list; /* Entry in plex's packet list. */
65};
66
67int	gv_stripe_active(struct gv_plex *, struct bio *);
68int	gv_build_raid5_req(struct gv_plex *, struct gv_raid5_packet *,
69	    struct bio *, caddr_t, off_t, off_t);
70int	gv_check_raid5(struct gv_plex *, struct gv_raid5_packet *,
71	    struct bio *, caddr_t, off_t, off_t);
72int	gv_rebuild_raid5(struct gv_plex *, struct gv_raid5_packet *,
73	    struct bio *, caddr_t, off_t, off_t);
74void	gv_raid5_worker(void *);
75void	gv_plex_done(struct bio *);
76
77#endif /* !_GEOM_VINUM_RAID5_H_ */
78