From patchwork Wed Apr 2 14:54:11 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Filipe Manana X-Patchwork-Id: 14036122 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C2B0023C8CC for ; Wed, 2 Apr 2025 14:54:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743605659; cv=none; b=jxExqnOfqYtp+1aijlLA5wL0xiVzyEB78CWMQu8oZu8FMflqxg2ZlwcyKFB16AXYkTbpmIdcUDFJGsebpJ9FQasu5GkZPYb+pcjUEkneGx4C1zPHKlpJI8WmOlRwL11ZVcDakQqYFnfIcRypQ+Qf1i7G844dXpLOCteVonehH3o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743605659; c=relaxed/simple; bh=qoPaV5QdIf7LLDf5kvIo+S19fQ80L0RJa7HzjpxuBno=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=hpRL0dJA+CNX2dYdRF4e82IcSoEGyMDTXiDu9paxfu8wTVgmz8pKiGU4G0YSUZzx1/iFlOzY3UBXEhAYF9GPikD/fEVTxQw6DOOaSXatsBUQwDMymJqJ3xQ3N1lLJkzEtFXIQDbTnjA5XK3gtFyk4K63hxpEM3GA47ymTuINzjg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZQ/pMfgl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZQ/pMfgl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFCE4C4CEEA for ; Wed, 2 Apr 2025 14:54:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743605659; bh=qoPaV5QdIf7LLDf5kvIo+S19fQ80L0RJa7HzjpxuBno=; h=From:To:Subject:Date:In-Reply-To:References:From; b=ZQ/pMfgl8xzR7H451jjTvfQJ5VoSKfdo75tooKFTRZeXUi9koO5bANhvoOugyMYzj mYhxoxxLZIm+sYlKDsxWWW7gD+MM4JWL7mQYQsiHTJRJQZV+3u1bYw24y4hiKMzlzG MCIJYxa9Ieszm+13MXzYsr7QXIL6cnaHZTZR9Cw2x2e9Nu6GXu480J7YtoaTz0blpr Ljf18g0EUS0dZZNFFHMNmQUkkwapbSzGqwkW5YCLnvTVbNAo9zU2bqq0OVhrBlk6ci VmdRrtmvr5TwbZkE2ch0bS+YbBJieX6aTyNWNAa5Y78RKajMnTptiySggi3zMyoTa6 q2j+9fSrzPbcw== From: fdmanana@kernel.org To: linux-btrfs@vger.kernel.org Subject: [PATCH 3/4] btrfs: simplify last record detection at test_range_bit() Date: Wed, 2 Apr 2025 15:54:11 +0100 Message-Id: <53c0bc370a45abf176ec74d1257f66cbdfdb645b.1743604119.git.fdmanana@suse.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Filipe Manana The overflow detection for the start offset of the next record is not really necessary, we can just stop iterating if the current record ends at or after out end offset. This removes the need to test if the current record end offset is (u64)-1 and to check if adding 1 to the current end offset results in 0. By testing only if the current record ends at or after the end offset, we also don't need anymore to test the new start offset at the head of the while loop. This makes both the source code and assembly code simpler, more efficient and shorter (reducing the object text size). Also remove the pointless initializion to NULL of the state variable, as we don't use it before the first assignment to it. This may help avoid some warnings with clang tools such as the one reported/fixed by commit 966de47ff0c9 ("btrfs: remove redundant initialization of variables in log_new_ancestors"). Signed-off-by: Filipe Manana --- fs/btrfs/extent-io-tree.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c index 18b10e7ed815..b321f826d008 100644 --- a/fs/btrfs/extent-io-tree.c +++ b/fs/btrfs/extent-io-tree.c @@ -1790,7 +1790,7 @@ void get_range_bits(struct extent_io_tree *tree, u64 start, u64 end, u32 *bits, bool test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, u32 bit, struct extent_state *cached) { - struct extent_state *state = NULL; + struct extent_state *state; bool bitset = true; ASSERT(is_power_of_2(bit)); @@ -1801,7 +1801,7 @@ bool test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, u32 bit, state = cached; else state = tree_search(tree, start); - while (state && start <= end) { + while (state) { if (state->start > start) { bitset = false; break; @@ -1815,16 +1815,11 @@ bool test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, u32 bit, break; } - if (state->end == (u64)-1) + if (state->end >= end) break; - /* - * Last entry (if state->end is (u64)-1 and overflow happens), - * or next entry starts after the range. - */ + /* Next state must start where this one ends. */ start = state->end + 1; - if (start > end || start == 0) - break; state = next_state(state); }