[PATCH] Btrfs: remove unused key assignment when doing a full send

[PATCH] Btrfs: remove unused key assignment when doing a full send

[fdmanana]

From: Filipe Manana <fdmanana@suse.com>

At send.c:full_send_tree() we were setting the 'key' variable in the loop
while never using it later. We were also using two btrfs_key variables
to store the initial key for search and the key found in every iteration
of the loop. So remove this useless key assignment and use the same
btrfs_key variable to store the initial search key and the key found in
each iteration. This was introduced in the initial send commit but was
never used (commit 31db9f7c23fb ("Btrfs: introduce BTRFS_IOC_SEND for
btrfs send/receive").

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/send.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 6ffe1c983b76..8acc0e712cfa 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -6451,7 +6451,6 @@ static int full_send_tree(struct send_ctx *sctx)
 	int ret;
 	struct btrfs_root *send_root = sctx->send_root;
 	struct btrfs_key key;
-	struct btrfs_key found_key;
 	struct btrfs_path *path;
 	struct extent_buffer *eb;
 	int slot;
@@ -6473,17 +6472,13 @@ static int full_send_tree(struct send_ctx *sctx)
 	while (1) {
 		eb = path->nodes[0];
 		slot = path->slots[0];
-		btrfs_item_key_to_cpu(eb, &found_key, slot);
+		btrfs_item_key_to_cpu(eb, &key, slot);
 
-		ret = changed_cb(path, NULL, &found_key,
+		ret = changed_cb(path, NULL, &key,
 				 BTRFS_COMPARE_TREE_NEW, sctx);
 		if (ret < 0)
 			goto out;
 
-		key.objectid = found_key.objectid;
-		key.type = found_key.type;
-		key.offset = found_key.offset + 1;
-
 		ret = btrfs_next_item(send_root, path);
 		if (ret < 0)
 			goto out;
-- 
2.11.0

Re: [PATCH] Btrfs: remove unused key assignment when doing a full send

[David Sterba]

On Mon, Jul 23, 2018 at 09:10:09AM +0100, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> At send.c:full_send_tree() we were setting the 'key' variable in the loop
> while never using it later. We were also using two btrfs_key variables
> to store the initial key for search and the key found in every iteration
> of the loop. So remove this useless key assignment and use the same
> btrfs_key variable to store the initial search key and the key found in
> each iteration. This was introduced in the initial send commit but was
> never used (commit 31db9f7c23fb ("Btrfs: introduce BTRFS_IOC_SEND for
> btrfs send/receive").
> 
> Signed-off-by: Filipe Manana <fdmanana@suse.com>

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