From 946c9256c6fabe8d3fe8e076df1c4290dcd778f2 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 17 May 2019 11:43:34 +0200 Subject: [PATCH] btrfs: factor out helper for counting data stripes Factor the sequence of ifs to a helper, the 'data stripes' here means the number of stripes without redundancy and parity. Signed-off-by: David Sterba --- fs/btrfs/volumes.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index bbc195c97c74..e9caba25ddb6 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -3474,6 +3474,18 @@ static int chunk_devid_filter(struct extent_buffer *leaf, return 1; } +static u64 calc_data_stripes(u64 type, int num_stripes) +{ + const int index = btrfs_bg_flags_to_raid_index(type); + const int ncopies = btrfs_raid_array[index].ncopies; + const int nparity = btrfs_raid_array[index].nparity; + + if (nparity) + return num_stripes - nparity; + else + return num_stripes / ncopies; +} + /* [pstart, pend) */ static int chunk_drange_filter(struct extent_buffer *leaf, struct btrfs_chunk *chunk, @@ -3483,22 +3495,15 @@ static int chunk_drange_filter(struct extent_buffer *leaf, int num_stripes = btrfs_chunk_num_stripes(leaf, chunk); u64 stripe_offset; u64 stripe_length; + u64 type; int factor; int i; if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID)) return 0; - if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP | - BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) { - factor = num_stripes / 2; - } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) { - factor = num_stripes - 1; - } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) { - factor = num_stripes - 2; - } else { - factor = num_stripes; - } + type = btrfs_chunk_type(leaf, chunk); + factor = calc_data_stripes(type, num_stripes); for (i = 0; i < num_stripes; i++) { stripe = btrfs_stripe_nr(chunk, i); -- 2.30.2