From: David Sterba <dsterba@suse.com>
Date: Mon, 26 Jul 2021 12:15:24 +0000 (+0200)
Subject: btrfs: simplify data stripe calculation helpers
X-Git-Tag: accepted/tizen/unified/20230118.172025~6109^2~102
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d58ede8d1d9fb0f70d6aa51fa6550d2d580f8c17;p=platform%2Fkernel%2Flinux-rpi.git

btrfs: simplify data stripe calculation helpers

There are two helpers doing the same calculations based on nparity and
ncopies. calc_data_stripes can be simplified into one expression, so far
we don't have profile with both copies and parity, so there's no
effective change. calc_stripe_length should reuse the helper and not
repeat the same calculation.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 23159bd..c7339f1 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3568,10 +3568,7 @@ static u64 calc_data_stripes(u64 type, int num_stripes)
 	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;
+	return (num_stripes - nparity) / ncopies;
 }
 
 /* [pstart, pend) */
@@ -6879,15 +6876,7 @@ static void btrfs_report_missing_device(struct btrfs_fs_info *fs_info,
 
 static u64 calc_stripe_length(u64 type, u64 chunk_len, int num_stripes)
 {
-	int index = btrfs_bg_flags_to_raid_index(type);
-	int ncopies = btrfs_raid_array[index].ncopies;
-	const int nparity = btrfs_raid_array[index].nparity;
-	int data_stripes;
-
-	if (nparity)
-		data_stripes = num_stripes - nparity;
-	else
-		data_stripes = num_stripes / ncopies;
+	const int data_stripes = calc_data_stripes(type, num_stripes);
 
 	return div_u64(chunk_len, data_stripes);
 }