From nobody Thu Apr 2 18:54:54 2026 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 0C30E3DB64B; Fri, 27 Mar 2026 09:24:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774603457; cv=none; b=nN0lnrXzh2huY6DRp0p2CCdRUJWFiaCIg1aANgAISTeCGanjpbmpJSkLKHa8AQP9a3D8XJbws2VgLLLGBnFfR6Jv7dAta7J3zzuu5FxWlu7UXC0wzr8bIqE8ud06vZvWOcfUWk5GRheIDdEEtjCHhUK6ygmBkT78WfyiWtOyNc0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774603457; c=relaxed/simple; bh=YOLokWSdToD8kI4grwc+wFe7gCSIYg9o99s09E+DHHU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=naWmYtU+pAGLpU6w/13ST4OEysxV30WzhGm6IZZQfvpKTZhNICOmxMsu79o+2S5TiqqxUfTNLPRb8GFj7r3QEGANnaIK2emgpy4r+//QLrpfi34QrE+276Na7UGtaGwyamL0vsqYwMG+dHHkFsq5I9kS1SzA13xLFNhOM6jE0eQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.198]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4fhwDg4WKxzKHMkH; Fri, 27 Mar 2026 17:23:31 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id 3BDB040574; Fri, 27 Mar 2026 17:24:13 +0800 (CST) Received: from huaweicloud.com (unknown [10.50.87.129]) by APP1 (Coremail) with SMTP id cCh0CgAHC9uyTMZpTlaWCQ--.27625S5; Fri, 27 Mar 2026 17:24:13 +0800 (CST) From: leo.lilong@huaweicloud.com To: josef@toxicpanda.com, axboe@kernel.dk Cc: leo.lilong@huawei.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com, lonuxli.64@gmail.com Subject: [PATCH 1/4] nbd: simplify find_fallback() by removing redundant logic Date: Fri, 27 Mar 2026 17:12:20 +0800 Message-Id: <20260327091223.4147956-2-leo.lilong@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20260327091223.4147956-1-leo.lilong@huaweicloud.com> References: <20260327091223.4147956-1-leo.lilong@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: cCh0CgAHC9uyTMZpTlaWCQ--.27625S5 X-Coremail-Antispam: 1UD129KBjvJXoW7Aw1fCF48uFW7tryUuFWkCrg_yoW8tFy7pF WfZFyfKryUJ3W3ur43Za1UuF15Cws3Ga1UGFW8Ja4xuryUCryUuFZ3tF1ftay5JrZxZFyq vF1UWFy7CFn8Gw7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBCb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUGw A2048vs2IY020Ec7CjxVAFwI0_JFI_Gr1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1Y6r17McIj6I8E87Iv67AKxVW8Jr0_Cr1UMcvjeVCFs4IE7xkE bVWUJVW8JwACjcxG0xvY0x0EwIxGrwAKzVCY07xG64k0F24lc7CjxVAaw2AFwI0_JF0_Jw 1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWU JVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7V AKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42 IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxU7zuWDUUUU X-CM-SenderInfo: hohrhzxlor0w46kxt4xhlfz01xgou0bp/ Content-Type: text/plain; charset="utf-8" From: Long Li Remove the intermediate new_index variable and return -1 directly. The second conditional checking nsock->fallback_index validity is the logical inverse of the first, so drop it and let execution fall through naturally. Consolidate the two identical dev_err_ratelimited() + return paths into a single no_fallback label to reduce duplication. Signed-off-by: Long Li --- drivers/block/nbd.c | 37 ++++++++++++++----------------------- 1 file changed, 14 insertions(+), 23 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index fe63f3c55d0d..f26ad2f1f3ff 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1061,40 +1061,31 @@ static int find_fallback(struct nbd_device *nbd, in= t index) int new_index =3D -1; struct nbd_sock *nsock =3D config->socks[index]; int fallback =3D nsock->fallback_index; + int i; =20 if (test_bit(NBD_RT_DISCONNECTED, &config->runtime_flags)) return new_index; =20 - if (config->num_connections <=3D 1) { - dev_err_ratelimited(disk_to_dev(nbd->disk), - "Dead connection, failed to find a fallback\n"); - return new_index; - } + if (config->num_connections <=3D 1) + goto no_fallback; =20 if (fallback >=3D 0 && fallback < config->num_connections && !config->socks[fallback]->dead) return fallback; =20 - if (nsock->fallback_index < 0 || - nsock->fallback_index >=3D config->num_connections || - config->socks[nsock->fallback_index]->dead) { - int i; - for (i =3D 0; i < config->num_connections; i++) { - if (i =3D=3D index) - continue; - if (!config->socks[i]->dead) { - new_index =3D i; - break; - } - } - nsock->fallback_index =3D new_index; - if (new_index < 0) { - dev_err_ratelimited(disk_to_dev(nbd->disk), - "Dead connection, failed to find a fallback\n"); - return new_index; + for (i =3D 0; i < config->num_connections; i++) { + if (i !=3D index && !config->socks[i]->dead) { + new_index =3D i; + break; } } - new_index =3D nsock->fallback_index; + nsock->fallback_index =3D new_index; + if (new_index >=3D 0) + return new_index; + +no_fallback: + dev_err_ratelimited(disk_to_dev(nbd->disk), + "Dead connection, failed to find a fallback\n"); return new_index; } =20 --=20 2.39.2