From patchwork Thu Nov 16 16:23:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Nan X-Patchwork-Id: 13457704 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C2A119D; Thu, 16 Nov 2023 00:29:05 -0800 (PST) Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4SWCqb4fFsz4f3kjs; Thu, 16 Nov 2023 16:28:59 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id 3528A1A01A5; Thu, 16 Nov 2023 16:29:02 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP1 (Coremail) with SMTP id cCh0CgCnqxHL0lVlgbRFBA--.19869S5; Thu, 16 Nov 2023 16:29:02 +0800 (CST) From: linan666@huaweicloud.com To: josef@toxicpanda.com, axboe@kernel.dk Cc: linux-block@vger.kernel.org, nbd@other.debian.org, linux-kernel@vger.kernel.org, linan122@huawei.com, yukuai3@huawei.com, yi.zhang@huawei.com, houtao1@huawei.com, yangerkun@huawei.com Subject: [PATCH 1/3] nbd: fold nbd config initialization into nbd_alloc_config() Date: Fri, 17 Nov 2023 00:23:14 +0800 Message-Id: <20231116162316.1740402-2-linan666@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231116162316.1740402-1-linan666@huaweicloud.com> References: <20231116162316.1740402-1-linan666@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: cCh0CgCnqxHL0lVlgbRFBA--.19869S5 X-Coremail-Antispam: 1UD129KBjvJXoWxXw43urWrAF1xGrWftr15XFb_yoW5ArWkpF 45AFWUKr48JF43GFWkA3s7WF15twn7GFy7Gry7J3Wvyr93CrWakr1kG34fZFyUJr9rJF15 JFWrWFWSka4xXrUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUQIb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M280x2IEY4vEnII2IxkI6r1a6r45M2 8IrcIa0xkI8VA2jI8067AKxVWUGwA2048vs2IY020Ec7CjxVAFwI0_JFI_Gr1l8cAvFVAK 0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4 x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l 84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2vYz4IE04k24VAvwVAKI4IrM2AIxVAIcx kEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v2 6r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2 Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lw4CEc2x0rVAKj4xxMxAIw28IcxkI7VAK I48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7 xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xII jxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw2 0EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x02 67AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU0uwZ3UUUUU== X-CM-SenderInfo: polqt0awwwqx5xdzvxpfor3voofrz/ From: Li Nan There are no functional changes, make the code cleaner and prepare to fix null-ptr-dereference while accessing 'nbd->config'. Signed-off-by: Li Nan --- drivers/block/nbd.c | 41 +++++++++++++++++++---------------------- 1 file changed, 19 insertions(+), 22 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index df1cd0f718b8..904d01796d37 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1530,17 +1530,20 @@ static int nbd_ioctl(struct block_device *bdev, blk_mode_t mode, return error; } -static struct nbd_config *nbd_alloc_config(void) +static int nbd_alloc_and_init_config(struct nbd_device *nbd) { struct nbd_config *config; + if (WARN_ON(nbd->config)) + return -EINVAL; + if (!try_module_get(THIS_MODULE)) - return ERR_PTR(-ENODEV); + return -ENODEV; config = kzalloc(sizeof(struct nbd_config), GFP_NOFS); if (!config) { module_put(THIS_MODULE); - return ERR_PTR(-ENOMEM); + return -ENOMEM; } atomic_set(&config->recv_threads, 0); @@ -1548,7 +1551,10 @@ static struct nbd_config *nbd_alloc_config(void) init_waitqueue_head(&config->conn_wait); config->blksize_bits = NBD_DEF_BLKSIZE_BITS; atomic_set(&config->live_connections, 0); - return config; + nbd->config = config; + refcount_set(&nbd->config_refs, 1); + + return 0; } static int nbd_open(struct gendisk *disk, blk_mode_t mode) @@ -1567,21 +1573,17 @@ static int nbd_open(struct gendisk *disk, blk_mode_t mode) goto out; } if (!refcount_inc_not_zero(&nbd->config_refs)) { - struct nbd_config *config; - mutex_lock(&nbd->config_lock); if (refcount_inc_not_zero(&nbd->config_refs)) { mutex_unlock(&nbd->config_lock); goto out; } - config = nbd_alloc_config(); - if (IS_ERR(config)) { - ret = PTR_ERR(config); + ret = nbd_alloc_and_init_config(nbd); + if (ret) { mutex_unlock(&nbd->config_lock); goto out; } - nbd->config = config; - refcount_set(&nbd->config_refs, 1); + refcount_inc(&nbd->refs); mutex_unlock(&nbd->config_lock); if (max_part) @@ -1982,22 +1984,17 @@ static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info) pr_err("nbd%d already in use\n", index); return -EBUSY; } - if (WARN_ON(nbd->config)) { - mutex_unlock(&nbd->config_lock); - nbd_put(nbd); - return -EINVAL; - } - config = nbd_alloc_config(); - if (IS_ERR(config)) { + + ret = nbd_alloc_and_init_config(nbd); + if (ret) { mutex_unlock(&nbd->config_lock); nbd_put(nbd); pr_err("couldn't allocate config\n"); - return PTR_ERR(config); + return ret; } - nbd->config = config; - refcount_set(&nbd->config_refs, 1); - set_bit(NBD_RT_BOUND, &config->runtime_flags); + config = nbd->config; + set_bit(NBD_RT_BOUND, &config->runtime_flags); ret = nbd_genl_size_set(info, nbd); if (ret) goto out;