linux-kernel - Re: [PATCH][next] bcachefs: remove redundant initialization of variable level

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Message-ID: <20231111210208.qra7xhf2nd4pqvst@moria.home.lan>
Date:   Sat, 11 Nov 2023 16:02:08 -0500
From:   Kent Overstreet <kent.overstreet@...ux.dev>
To:     Colin Ian King <colin.i.king@...il.com>
Cc:     Brian Foster <bfoster@...hat.com>, linux-bcachefs@...r.kernel.org,
        kernel-janitors@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH][next] bcachefs: remove redundant initialization of
 variable level

On Sat, Nov 11, 2023 at 08:45:28PM +0000, Colin Ian King wrote:
> Variable level is being initialized a value that is never read, the
> variable is being re-assigned another value several statements later
> on. The initialization is redundant and can be removed. Cleans up
> clang scan build warning:
> 
> fs/bcachefs/btree_iter.c:1217:11: warning: Value stored to 'level'
> during its initialization is never read [deadcode.DeadStores]
> 
> Signed-off-by: Colin Ian King <colin.i.king@...il.com>

since we're no longer gnu89, we can simply declare the variable when
it's first used, like so:

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index 96bdf0c6051c..104172f6822b 100644
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -1214,8 +1214,6 @@ __bch2_btree_path_set_pos(struct btree_trans *trans,
 		   struct btree_path *path, struct bpos new_pos,
 		   bool intent, unsigned long ip, int cmp)
 {
-	unsigned level = path->level;
-
 	bch2_trans_verify_not_in_restart(trans);
 	EBUG_ON(!path->ref);
 
@@ -1231,7 +1229,7 @@ __bch2_btree_path_set_pos(struct btree_trans *trans,
 		goto out;
 	}
 
-	level = btree_path_up_until_good_node(trans, path, cmp);
+	unsigned level = btree_path_up_until_good_node(trans, path, cmp);
 
 	if (btree_path_node(path, level)) {
 		struct btree_path_level *l = &path->l[level];