xref: /openbmc/linux/drivers/md/raid0.h (revision fb3bd914)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _RAID0_H
3 #define _RAID0_H
4 
5 struct strip_zone {
6 	sector_t zone_end;	/* Start of the next zone (in sectors) */
7 	sector_t dev_start;	/* Zone offset in real dev (in sectors) */
8 	int	 nb_dev;	/* # of devices attached to the zone */
9 	int	 disk_shift;	/* start disk for the original layout */
10 };
11 
12 /* Linux 3.14 (20d0189b101) made an unintended change to
13  * the RAID0 layout for multi-zone arrays (where devices aren't all
14  * the same size.
15  * RAID0_ORIG_LAYOUT restores the original layout
16  * RAID0_ALT_MULTIZONE_LAYOUT uses the altered layout
17  * The layouts are identical when there is only one zone (all
18  * devices the same size).
19  */
20 
21 enum r0layout {
22 	RAID0_ORIG_LAYOUT = 1,
23 	RAID0_ALT_MULTIZONE_LAYOUT = 2,
24 };
25 struct r0conf {
26 	struct strip_zone	*strip_zone;
27 	struct md_rdev		**devlist; /* lists of rdevs, pointed to
28 					    * by strip_zone->dev */
29 	int			nr_strip_zones;
30 	enum r0layout		layout;
31 };
32 
33 #endif
34