xref: /openbmc/linux/drivers/md/raid0.h (revision e8360070)
1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */
2ef740c37SChristoph Hellwig #ifndef _RAID0_H
3ef740c37SChristoph Hellwig #define _RAID0_H
4ef740c37SChristoph Hellwig 
5e373ab10SNeilBrown struct strip_zone {
6dc582663SAndre Noll 	sector_t zone_end;	/* Start of the next zone (in sectors) */
7ef740c37SChristoph Hellwig 	sector_t dev_start;	/* Zone offset in real dev (in sectors) */
8ef740c37SChristoph Hellwig 	int	 nb_dev;	/* # of devices attached to the zone */
9*e8360070SJason Baron 	int	 disk_shift;	/* start disk for the original layout */
10ef740c37SChristoph Hellwig };
11ef740c37SChristoph Hellwig 
12c84a1372SNeilBrown /* Linux 3.14 (20d0189b101) made an unintended change to
13c84a1372SNeilBrown  * the RAID0 layout for multi-zone arrays (where devices aren't all
14c84a1372SNeilBrown  * the same size.
15c84a1372SNeilBrown  * RAID0_ORIG_LAYOUT restores the original layout
16c84a1372SNeilBrown  * RAID0_ALT_MULTIZONE_LAYOUT uses the altered layout
17c84a1372SNeilBrown  * The layouts are identical when there is only one zone (all
18c84a1372SNeilBrown  * devices the same size).
19c84a1372SNeilBrown  */
20c84a1372SNeilBrown 
21c84a1372SNeilBrown enum r0layout {
22c84a1372SNeilBrown 	RAID0_ORIG_LAYOUT = 1,
23c84a1372SNeilBrown 	RAID0_ALT_MULTIZONE_LAYOUT = 2,
24c84a1372SNeilBrown };
25e373ab10SNeilBrown struct r0conf {
26ef740c37SChristoph Hellwig 	struct strip_zone	*strip_zone;
27ba13da47SNeilBrown 	struct md_rdev		**devlist; /* lists of rdevs, pointed to
28ba13da47SNeilBrown 					    * by strip_zone->dev */
29ef740c37SChristoph Hellwig 	int			nr_strip_zones;
30c84a1372SNeilBrown 	enum r0layout		layout;
31ef740c37SChristoph Hellwig };
32ef740c37SChristoph Hellwig 
33ef740c37SChristoph Hellwig #endif
34