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Date:   Thu,  4 Feb 2021 23:28:50 +0000
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Subject: [PATCH v2 2/2] dmabuf: Add dmabuf inode number to /proc/*/fdinfo
From:   Kalesh Singh <kaleshsingh@google.com>
Cc:     jannh@google.com, jeffv@google.com, keescook@chromium.org,
        surenb@google.com, minchan@kernel.org, hridya@google.com,
        kernel-team@android.com, Kalesh Singh <kaleshsingh@google.com>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        "=?UTF-8?q?Christian=20K=C3=B6nig?=" <christian.koenig@amd.com>,
        Alexey Dobriyan <adobriyan@gmail.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexey Gladkov <gladkov.alexey@gmail.com>,
        Michel Lespinasse <walken@google.com>,
        Bernd Edlinger <bernd.edlinger@hotmail.de>,
        Andrei Vagin <avagin@gmail.com>,
        Yafang Shao <laoar.shao@gmail.com>,
        Christian Brauner <christian.brauner@ubuntu.com>,
        linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
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If a FD refers to a DMA buffer add the DMA buffer inode number to
/proc/<pid>/fdinfo/<FD> and /proc/<pid>/task/<tid>/fdindo/<FD>.

The dmabuf inode number allows userspace to uniquely identify the buffer
and avoids a dependency on /proc/<pid>/fd/* when accounting per-process
DMA buffer sizes.

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
---

Changes in v2: 
  - Update patch desciption

 drivers/dma-buf/dma-buf.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 9ad6397aaa97..d869099ede83 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -414,6 +414,7 @@ static void dma_buf_show_fdinfo(struct seq_file *m, struct file *file)
 {
 	struct dma_buf *dmabuf = file->private_data;
 
+	seq_printf(m, "dmabuf_inode_no:\t%lu\n", file_inode(file)->i_ino);
 	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);
-- 
2.30.0.365.g02bc693789-goog