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 586BCC433F5 for ; Tue, 26 Oct 2021 08:04:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DC36610A0 for ; Tue, 26 Oct 2021 08:04:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233646AbhJZIHO (ORCPT ); Tue, 26 Oct 2021 04:07:14 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:52348 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S233058AbhJZIHM (ORCPT ); Tue, 26 Oct 2021 04:07:12 -0400 X-UUID: a06a541a01624b4490537ec3abd7a2c1-20211026 X-UUID: a06a541a01624b4490537ec3abd7a2c1-20211026 Received: from mtkmbs10n2.mediatek.inc [(172.21.101.183)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 1877048041; Tue, 26 Oct 2021 16:04:46 +0800 Received: from mtkcas10.mediatek.inc (172.21.101.39) 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; Tue, 26 Oct 2021 16:04:45 +0800 Received: from mszswglt01.gcn.mediatek.inc (10.16.20.20) by mtkcas10.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 26 Oct 2021 16:04:44 +0800 From: To: , CC: , , , , , , , , , , Guangming Cao Subject: [PATCH v3] dma-buf: remove restriction of IOCTL:DMA_BUF_SET_NAME Date: Tue, 26 Oct 2021 16:04:51 +0800 Message-ID: <20211026080451.3763-1-guangming.cao@mediatek.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211014102551.54983-1-guangming.cao@mediatek.com> References: <20211014102551.54983-1-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 On Thu, 2021-10-14 at 18:25 +0800, guangming.cao@mediatek.com wrote: > 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. > Hi christian, sumit, Just a gentle ping for this patch, please kindly let me know your comments about this patch. Thanks! Guangming > 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,