xref: /openbmc/linux/fs/btrfs/raid56.h (revision 12eb4683)
1 /*
2  * Copyright (C) 2012 Fusion-io  All rights reserved.
3  * Copyright (C) 2012 Intel Corp. All rights reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public
7  * License v2 as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public
15  * License along with this program; if not, write to the
16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17  * Boston, MA 021110-1307, USA.
18  */
19 
20 #ifndef __BTRFS_RAID56__
21 #define __BTRFS_RAID56__
22 static inline int nr_parity_stripes(struct map_lookup *map)
23 {
24 	if (map->type & BTRFS_BLOCK_GROUP_RAID5)
25 		return 1;
26 	else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
27 		return 2;
28 	else
29 		return 0;
30 }
31 
32 static inline int nr_data_stripes(struct map_lookup *map)
33 {
34 	return map->num_stripes - nr_parity_stripes(map);
35 }
36 #define RAID5_P_STRIPE ((u64)-2)
37 #define RAID6_Q_STRIPE ((u64)-1)
38 
39 #define is_parity_stripe(x) (((x) == RAID5_P_STRIPE) ||		\
40 			     ((x) == RAID6_Q_STRIPE))
41 
42 int raid56_parity_recover(struct btrfs_root *root, struct bio *bio,
43 				 struct btrfs_bio *bbio, u64 *raid_map,
44 				 u64 stripe_len, int mirror_num);
45 int raid56_parity_write(struct btrfs_root *root, struct bio *bio,
46 			       struct btrfs_bio *bbio, u64 *raid_map,
47 			       u64 stripe_len);
48 
49 int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info);
50 void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info);
51 #endif
52