From patchwork Tue Apr 1 15:29:54 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Filipe Manana X-Patchwork-Id: 14035013 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 1CD6120AF9C for ; Tue, 1 Apr 2025 15:30:01 +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=1743521402; cv=none; b=CXriR/4kOusgc/zQiu22nQywx3HtYS/l2+6zpdvpMi2rpoTyg/UcJVhVL9qVzjJu6rs1sHsXk4G8FD1PvdXtoMPb7jnQv0GcPjsPpVqtGZ5ckRU1kkuVucwemwiSvVHFpLs197XTQSd1zpz7qsEJ/Wqm2H09ROD/yHS68AQtOQI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743521402; c=relaxed/simple; bh=MFnql+bSP4O26kxVBWK3934LoboUHc7LIgldAXvi49k=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=dwrmQci88NmHpLe8rxSP63Alz3zp/Eu5uTY7ALmYmxhvFJB1HWhZ7jthXF1eRdjfENkNa8n1UQLRSIg3TWX5ZT5GP63FqqZIlWYgYrH2pLcYUsdWKBNLCIEEwQJz4/onKsu6x5bWllWqpPknBfBUhQDmWVrj9eqQRNF0Dn7lRcg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LMmYa7CY; 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="LMmYa7CY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C298C4CEE8 for ; Tue, 1 Apr 2025 15:30:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743521401; bh=MFnql+bSP4O26kxVBWK3934LoboUHc7LIgldAXvi49k=; h=From:To:Subject:Date:In-Reply-To:References:From; b=LMmYa7CYxjrbZJ7ZgDBIt49/TA+mI8xn3R5CkLuBTPMNeJEbDuxSJ6tg+ZGSBjyeD 5VK4sdPRRcmUaIsP3K/MrhMnA7USr3Q24ExeBVBxQrtEPOxOUi/PsMf+Xg8NGH0Voy vXz51s8G0w1OzCrBAMg9B0flHBG54K7wb3kz7rmq+Vd1YDIS0O3Mb9aRtl9AXvek+n smwxB1ZyRS3zwPRDJxDk/SZDTVjJdqZzY9T9pzjijYI0yeyGleaaBL7r5UUHbvkIF/ bz0JfliEessi7EpVq64RfRFO9uf29SZZ7KCBSbKNKMBKO5SbBxwsK/KWa/fNUN1smK +MiioHmuuFJvg== From: fdmanana@kernel.org To: linux-btrfs@vger.kernel.org Subject: [PATCH v2 4/4] btrfs: simplify last record detection at test_range_bit_exists() Date: Tue, 1 Apr 2025 16:29:54 +0100 Message-Id: <9ee50767c1bbb59d408c2df7d6e0a4e1635289cf.1743521098.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 Instead of keeping track of the minimum start offset of the next record and detecting overflow everytime we update that offset to be the sum of current record's end offset plus one, we can simply exit when the current record ends at or beyond our end offset and forget about updating the start offset on every iteration and testing for it at the top of the 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 | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c index 7ae24a533404..293cb354259d 100644 --- a/fs/btrfs/extent-io-tree.c +++ b/fs/btrfs/extent-io-tree.c @@ -1726,14 +1726,14 @@ u64 count_range_bits(struct extent_io_tree *tree, */ bool test_range_bit_exists(struct extent_io_tree *tree, u64 start, u64 end, u32 bit) { - struct extent_state *state = NULL; + struct extent_state *state; bool bitset = false; ASSERT(is_power_of_2(bit)); spin_lock(&tree->lock); state = tree_search(tree, start); - while (state && start <= end) { + while (state) { if (state->start > end) break; @@ -1742,9 +1742,7 @@ bool test_range_bit_exists(struct extent_io_tree *tree, u64 start, u64 end, u32 break; } - /* If state->end is (u64)-1, start will overflow to 0 */ - start = state->end + 1; - if (start > end || start == 0) + if (state->end >= end) break; state = next_state(state); }