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 <dsterba@suse.com>
This commit is contained in:
David Sterba 2019-05-17 11:43:34 +02:00
parent 44b28adafd
commit 946c9256c6

View File

@ -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);