btrfs: simplify percent calculation helpers, rename div_factor

The div_factor* helpers calculate fraction or percentage fraction. The
name is a bit confusing, we use it only for percentage calculations and
there are two helpers.

There's a helper mult_frac that's for general fractions, that tries to
be accurate but we multiply and divide by small numbers so we can use
the div_u64 helper.

Rename the div_factor* helpers and use 1..100 percentage range, also drop
the case checking for percentage == 100, it's never hit.

The conversions:

* div_factor calculates tenths and the numbers need to be adjusted
* div_factor_fine is direct replacement

Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index cfe495d39ebd..ea5fcb665daa 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1551,7 +1551,7 @@ static bool should_reclaim_block_group(struct btrfs_block_group *bg, u64 bytes_f
 	if (reclaim_thresh == 0)
 		return false;
 
-	thresh = div_factor_fine(bg->length, reclaim_thresh);
+	thresh = mult_perc(bg->length, reclaim_thresh);
 
 	/*
 	 * If we were below the threshold before don't reclaim, we are likely a
@@ -3523,13 +3523,13 @@ static int should_alloc_chunk(struct btrfs_fs_info *fs_info,
 	 */
 	if (force == CHUNK_ALLOC_LIMITED) {
 		thresh = btrfs_super_total_bytes(fs_info->super_copy);
-		thresh = max_t(u64, SZ_64M, div_factor_fine(thresh, 1));
+		thresh = max_t(u64, SZ_64M, mult_perc(thresh, 1));
 
 		if (sinfo->total_bytes - bytes_used < thresh)
 			return 1;
 	}
 
-	if (bytes_used + SZ_2M < div_factor(sinfo->total_bytes, 8))
+	if (bytes_used + SZ_2M < mult_perc(sinfo->total_bytes, 80))
 		return 0;
 	return 1;
 }