[PATCH 2/2] dmabuf: Add dmabuf inode no to fdinfo

[Randy Dunlap]

On 1/28/21 10:24 AM, Kalesh Singh wrote:
> 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 at google.com>
> ---
>  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);
> 

Hi,

The subject is a little confusing.
It seems to say that the dmabuf inode no is being added to /proc/<pid>/fdino,
but looking at the code, it is being added to /proc/dmabuf (or /proc/<pid>/dmabuf).

Please clarify.

and is the /proc file format documented anywhere?


thanks.

-- 
~Randy