xref: /freebsd/sys/geom/vinum/geom_vinum_raid5.h (revision 3bdf775801b218aa5a89564839405b122f4b233e)
1 /*-
2  * Copyright (c) 2004, 2007 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  * $FreeBSD$
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 struct gv_raid5_packet {
39 	caddr_t	data;		/* Data buffer of this sub-request- */
40 	off_t	length;		/* Size of data buffer. */
41 	off_t	lockbase;	/* Deny access to our plex offset. */
42 
43 	struct bio	*bio;	/* Pointer to the original bio. */
44 	struct bio	*parity;  /* The bio containing the parity data. */
45 	struct bio	*waiting; /* A bio that need to wait for other bios. */
46 
47 	TAILQ_HEAD(,gv_bioq)		bits; /* List of subrequests. */
48 	TAILQ_ENTRY(gv_raid5_packet)	list; /* Entry in plex's packet list. */
49 };
50 
51 struct gv_raid5_packet * gv_raid5_start(struct gv_plex *, struct bio *,
52 		caddr_t, off_t, off_t);
53 int	gv_stripe_active(struct gv_plex *, struct bio *);
54 
55 #endif /* !_GEOM_VINUM_RAID5_H_ */
56