fs/btrfs/raid56.h

   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 struct btrfs_raid_bio;
  43 struct btrfs_device;
  44
  45 int raid56_parity_recover(struct btrfs_root *root, struct bio *bio,
  46                           struct btrfs_bio *bbio, u64 stripe_len,
  47                           int mirror_num, int generic_io);
  48 int raid56_parity_write(struct btrfs_root *root, struct bio *bio,
  49                                struct btrfs_bio *bbio, u64 stripe_len);
  50
  51 struct btrfs_raid_bio *
  52 raid56_parity_alloc_scrub_rbio(struct btrfs_root *root, struct bio *bio,
  53                                struct btrfs_bio *bbio, u64 stripe_len,
  54                                struct btrfs_device *scrub_dev,
  55                                unsigned long *dbitmap, int stripe_nsectors);
  56 void raid56_parity_add_scrub_pages(struct btrfs_raid_bio *rbio,
  57                                    struct page *page, u64 logical);
  58 void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio);
  59
  60 int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info);
  61 void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info);
  62 #endif