[04/19] btrfs: don't use set/get token in leaf_space_used

Commit Message

David Sterba May 7, 2020, 8:19 p.m. UTC

The token is supposed to cache the last page used by the set/get
helpers. In leaf_space_used the first and last items are accessed, it's
not likely they'd be on the same page so there's some overhead caused
updating the token address but not using it.

Signed-off-by: David Sterba <[e-mail]>
---
 fs/btrfs/ctree.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

Comments

Johannes Thumshirn May 8, 2020, 1:27 p.m. UTC | #1

On 07/05/2020 22:20, David Sterba wrote:
> +	data_len = data_len - btrfs_item_offset(l, end_item);

Nit: Could again be data_len -= btrfs_item_offset(l, end_item);
Otherwise,
Reviewed-by: Johannes Thumshirn <[e-mail]>

Patch

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 576111cdea1d..6dbeb23c59ec 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -3507,19 +3507,17 @@  static int leaf_space_used(struct extent_buffer *l, int start, int nr)
 {
 	struct btrfs_item *start_item;
 	struct btrfs_item *end_item;
-	struct btrfs_map_token token;
 	int data_len;
 	int nritems = btrfs_header_nritems(l);
 	int end = min(nritems, start + nr) - 1;
 
 	if (!nr)
 		return 0;
-	btrfs_init_map_token(&token, l);
 	start_item = btrfs_item_nr(start);
 	end_item = btrfs_item_nr(end);
-	data_len = btrfs_token_item_offset(&token, start_item) +
-		btrfs_token_item_size(&token, start_item);
-	data_len = data_len - btrfs_token_item_offset(&token, end_item);
+	data_len = btrfs_item_offset(l, start_item) +
+		   btrfs_item_size(l, start_item);
+	data_len = data_len - btrfs_item_offset(l, end_item);
 	data_len += sizeof(struct btrfs_item) * nr;
 	WARN_ON(data_len < 0);
 	return data_len;