[RFC dma-buf 3/3] dma-buf: add show_fdinfo handler

From: Chenbo Feng
Date: Tue Feb 26 2019 - 22:55:09 EST


From: Greg Hackmann <ghackmann@xxxxxxxxxx>

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

Signed-off-by: Greg Hackmann <ghackmann@xxxxxxxxxx>
Signed-off-by: Chenbo Feng <fengc@xxxxxxxxxx>
---
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