From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4049CC4332F for ; Thu, 14 Oct 2021 10:26:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A5E0610CC for ; Thu, 14 Oct 2021 10:26:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230380AbhJNK2X (ORCPT ); Thu, 14 Oct 2021 06:28:23 -0400 Received: from mailgw01.mediatek.com ([60.244.123.138]:39604 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S230313AbhJNK2C (ORCPT ); Thu, 14 Oct 2021 06:28:02 -0400 X-UUID: 1a8d7129b1744671aff135bc3ae3ebfa-20211014 X-UUID: 1a8d7129b1744671aff135bc3ae3ebfa-20211014 Received: from mtkmbs10n1.mediatek.inc [(172.21.101.34)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 95578546; Thu, 14 Oct 2021 18:25:55 +0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs10n1.mediatek.inc (172.21.101.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.15; Thu, 14 Oct 2021 18:25:54 +0800 Received: from mszswglt01.gcn.mediatek.inc (10.16.20.20) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Thu, 14 Oct 2021 18:25:53 +0800 From: To: , CC: , , , , , , , , , , Guangming Cao Subject: [PATCH v3] dma-buf: remove restriction of IOCTL:DMA_BUF_SET_NAME Date: Thu, 14 Oct 2021 18:25:51 +0800 Message-ID: <20211014102551.54983-1-guangming.cao@mediatek.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211012084109.176542-1-guangming.cao@mediatek.com> References: <20211012084109.176542-1-guangming.cao@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Guangming Cao In this patch(https://patchwork.freedesktop.org/patch/310349), it add a new IOCTL to support dma-buf user to set debug name. But it also added a limitation of this IOCTL, it needs the attachments of dmabuf should be empty, otherwise it will fail. For the original series, the idea was that allowing name change mid-use could confuse the users about the dma-buf. However, the rest of the series also makes sure each dma-buf have a unique inode(https://patchwork.freedesktop.org/patch/310387/), and any accounting should probably use that, without relying on the name as much. So, removing this restriction will let dma-buf userspace users to use it more comfortably and without any side effect. Signed-off-by: Guangming Cao --- drivers/dma-buf/dma-buf.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 511fe0d217a0..5fbb3a2068a3 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -325,10 +325,8 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll) /** * dma_buf_set_name - Set a name to a specific dma_buf to track the usage. - * The name of the dma-buf buffer can only be set when the dma-buf is not - * attached to any devices. It could theoritically support changing the - * name of the dma-buf if the same piece of memory is used for multiple - * purpose between different devices. + * It could support changing the name of the dma-buf if the same + * piece of memory is used for multiple purpose between different devices. * * @dmabuf: [in] dmabuf buffer that will be renamed. * @buf: [in] A piece of userspace memory that contains the name of @@ -341,25 +339,16 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll) static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf) { char *name = strndup_user(buf, DMA_BUF_NAME_LEN); - long ret = 0; if (IS_ERR(name)) return PTR_ERR(name); - dma_resv_lock(dmabuf->resv, NULL); - if (!list_empty(&dmabuf->attachments)) { - ret = -EBUSY; - kfree(name); - goto out_unlock; - } spin_lock(&dmabuf->name_lock); kfree(dmabuf->name); dmabuf->name = name; spin_unlock(&dmabuf->name_lock); -out_unlock: - dma_resv_unlock(dmabuf->resv); - return ret; + return 0; } static long dma_buf_ioctl(struct file *file, -- 2.17.1