[PATCH v4 3/3] dma-buf: add show_fdinfo handler

[Chenbo Feng]

From: Greg Hackmann <ghackm...@google.com>

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

Signed-off-by: Greg Hackmann <ghackm...@google.com>
Signed-off-by: Chenbo Feng <fe...@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 87a928c93c1a..ff8421668331 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -396,6 +396,20 @@ 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,
@@ -405,6 +419,7 @@ static const struct file_operations dma_buf_fops = {
 #ifdef CONFIG_COMPAT
        .compat_ioctl   = dma_buf_ioctl,
 #endif
+       .show_fdinfo    = dma_buf_show_fdinfo,
 };
 
 /*
-- 
2.22.0.rc2.383.gf4fbbf30c2-goog