btrfs: use btrfs_raid_array to calculate number of parity stripes

Use the raid table instead of hard coded values and rename the helper as
it is exported.  This could make later extension on RAID56 based
profiles easier.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index f002334d244a77b56739df1477894e3a0a8fbf2e..0f0368e63e5af14fbbdde3497f98801897a17368 100644 (file)
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -922,7 +922,6 @@ static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info,
        const unsigned int stripe_nsectors = stripe_len >> fs_info->sectorsize_bits;
        const unsigned int num_sectors = stripe_nsectors * real_stripes;
        struct btrfs_raid_bio *rbio;
-       int nr_data = 0;
        void *p;
 
        ASSERT(IS_ALIGNED(stripe_len, PAGE_SIZE));
@@ -976,14 +975,9 @@ static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info,
        CONSUME_ALLOC(rbio->finish_pointers, real_stripes);
 #undef  CONSUME_ALLOC
 
-       if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID5)
-               nr_data = real_stripes - 1;
-       else if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID6)
-               nr_data = real_stripes - 2;
-       else
-               BUG();
+       ASSERT(btrfs_nr_parity_stripes(bioc->map_type));
+       rbio->nr_data = real_stripes - btrfs_nr_parity_stripes(bioc->map_type);
 
-       rbio->nr_data = nr_data;
        return rbio;
 }
 

diff --git a/fs/btrfs/raid56.h b/fs/btrfs/raid56.h
index 3b22657ca857e3b8f362cfd6970b281593226266..c73bceb2b461625b7529f7c445c61269e46feb60 100644 (file)
--- a/fs/btrfs/raid56.h
+++ b/fs/btrfs/raid56.h
@@ -155,19 +155,9 @@ struct raid56_bio_trace_info {
        u8 stripe_nr;
 };
 
-static inline int nr_parity_stripes(const struct map_lookup *map)
-{
-       if (map->type & BTRFS_BLOCK_GROUP_RAID5)
-               return 1;
-       else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
-               return 2;
-       else
-               return 0;
-}
-
 static inline int nr_data_stripes(const struct map_lookup *map)
 {
-       return map->num_stripes - nr_parity_stripes(map);
+       return map->num_stripes - btrfs_nr_parity_stripes(map->type);
 }
 
 #define RAID5_P_STRIPE ((u64)-2)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 75a59423a1bfefcf4ddfaa05df5e41477e25cf32..e40c0d59c4a07ea1ab5945b2ac7e9c0d0741ff5a 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -182,6 +182,13 @@ const char *btrfs_bg_type_to_raid_name(u64 flags)
        return btrfs_raid_array[index].raid_name;
 }
 
+int btrfs_nr_parity_stripes(u64 type)
+{
+       enum btrfs_raid_types index = btrfs_bg_flags_to_raid_index(type);
+
+       return btrfs_raid_array[index].nparity;
+}
+
 /*
  * Fill @buf with textual description of @bg_flags, no more than @size_buf
  * bytes including terminating null byte.

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index f19916a69beafa236d063af2a0cea9dd769409b8..b61508723d5d2209ed708566da8479a487c6c149 100644 (file)
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -634,6 +634,7 @@ int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
                                    u64 logical);
 u64 btrfs_calc_stripe_length(const struct extent_map *em);
+int btrfs_nr_parity_stripes(u64 type);
 int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans,
                                     struct btrfs_block_group *bg);
 int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);