Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Tue, 26 Feb 2019 19:54:48 -0800
In-Reply-To: <20190227035448.117169-1-fengc@google.com>
Message-Id: <20190227035448.117169-4-fengc@google.com>
Mime-Version: 1.0
References: <20190227035448.117169-1-fengc@google.com>
Subject: [RFC dma-buf 3/3] dma-buf: add show_fdinfo handler
From:   Chenbo Feng <fengc@google.com>
To:     linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linux-media@vger.kernel.org
Cc:     Sumit Semwal <sumit.semwal@linaro.org>, erickreyes@google.com,
        Greg Hackmann <ghackmann@google.com>,
        Chenbo Feng <fengc@google.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Greg Hackmann <ghackmann@google.com>

The show_fdinfo handler exports the same information available through
debugfs on a per-buffer basis.

Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Chenbo Feng <fengc@google.com>
---
 drivers/dma-buf/dma-buf.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index e0d9cdd3520b..2da3e2653f92 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -377,6 +377,20 @@ static long dma_buf_ioctl(struct file *file,
 	}
 }
 
+static void dma_buf_show_fdinfo(struct seq_file *m, struct file *file)
+{
+	struct dma_buf *dmabuf = file->private_data;
+
+	seq_printf(m, "size:\t%zu\n", dmabuf->size);
+	/* Don't count the temporary reference taken inside procfs seq_show */
+	seq_printf(m, "count:\t%ld\n", file_count(dmabuf->file) - 1);
+	seq_printf(m, "exp_name:\t%s\n", dmabuf->exp_name);
+	mutex_lock(&dmabuf->lock);
+	if (dmabuf->name)
+		seq_printf(m, "name:\t%s\n", dmabuf->name);
+	mutex_unlock(&dmabuf->lock);
+}
+
 static const struct file_operations dma_buf_fops = {
 	.release	= dma_buf_release,
 	.mmap		= dma_buf_mmap_internal,
@@ -386,6 +400,7 @@ static const struct file_operations dma_buf_fops = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= dma_buf_ioctl,
 #endif
+	.show_fdinfo	= dma_buf_show_fdinfo,
 };
 
 /*
-- 
2.21.0.rc2.261.ga7da99ff1b-goog