From patchwork Wed Feb 26 11:18:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yufen Yu X-Patchwork-Id: 11406067 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F1C0092A for ; Wed, 26 Feb 2020 11:11:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D031D24690 for ; Wed, 26 Feb 2020 11:11:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728060AbgBZLLu (ORCPT ); Wed, 26 Feb 2020 06:11:50 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:38292 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727891AbgBZLLs (ORCPT ); Wed, 26 Feb 2020 06:11:48 -0500 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 6FC2E719D1F313B2E02F; Wed, 26 Feb 2020 19:11:45 +0800 (CST) Received: from huawei.com (10.90.53.225) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.439.0; Wed, 26 Feb 2020 19:11:41 +0800 From: Yufen Yu To: , , CC: , , , Subject: [PATCH v2 4/7] bdi: create a new function bdi_get_dev_name() Date: Wed, 26 Feb 2020 19:18:48 +0800 Message-ID: <20200226111851.55348-5-yuyufen@huawei.com> X-Mailer: git-send-email 2.16.2.dirty In-Reply-To: <20200226111851.55348-1-yuyufen@huawei.com> References: <20200226111851.55348-1-yuyufen@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.90.53.225] X-CFilter-Loop: Reflected Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org We prepare a new function bdi_get_dev_name() to copy device kobj->name into buffer passed by caller. The function is covered by RCU. Thus, caller can access ->dev and copy integral device name. Signed-off-by: Yufen Yu --- include/linux/backing-dev.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 67e429b203a1..89d1cb7923f5 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -514,4 +514,29 @@ static inline const char *bdi_dev_name(struct backing_dev_info *bdi) return dev_name(&bdi->rcu_dev->dev); } +/** + * bdi_get_dev_name - copy bdi device name into buffer + * @bdi: target bdi + * @dname: Where to copy the device name to + * @len: size of destination buffer + */ +static inline void bdi_get_dev_name(struct backing_dev_info *bdi, + char *dname, int len) +{ + struct bdi_rcu_device *rcu_dev; + + if (!bdi) { + strlcpy(dname, bdi_unknown_name, len); + return; + } + + rcu_read_lock(); + + rcu_dev = rcu_dereference(bdi->rcu_dev); + strlcpy(dname, rcu_dev ? dev_name(&rcu_dev->dev) : + bdi_unknown_name, len); + + rcu_read_unlock(); +} + #endif /* _LINUX_BACKING_DEV_H */