From: Guangming Cao Guangming.Cao@mediatek.com
On Thu, 2021-10-14 at 18:25 +0800, guangming.cao@mediatek.com wrote:
From: Guangming Cao Guangming.Cao@mediatek.com
In this patch(https://patchwork.freedesktop.org/patch/310349), it add a new IOCTL to support dma-buf user to set debug name.
But it also added a limitation of this IOCTL, it needs the attachments of dmabuf should be empty, otherwise it will fail.
For the original series, the idea was that allowing name change mid-use could confuse the users about the dma-buf. However, the rest of the series also makes sure each dma-buf have a unique inode(https://patchwork.freedesktop.org/patch/310387/), and any accounting should probably use that, without relying on the name as much.
So, removing this restriction will let dma-buf userspace users to use it more comfortably and without any side effect.
Hi christian, sumit,
Just a gentle ping for this patch, please kindly let me know your comments about this patch. Thanks!
Guangming
Signed-off-by: Guangming Cao Guangming.Cao@mediatek.com
drivers/dma-buf/dma-buf.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 511fe0d217a0..5fbb3a2068a3 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -325,10 +325,8 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
/**
- dma_buf_set_name - Set a name to a specific dma_buf to track the
usage.
- The name of the dma-buf buffer can only be set when the dma-buf
is not
- attached to any devices. It could theoritically support changing
the
- name of the dma-buf if the same piece of memory is used for
multiple
- purpose between different devices.
- It could support changing the name of the dma-buf if the same
- piece of memory is used for multiple purpose between different
devices.
- @dmabuf: [in] dmabuf buffer that will be renamed.
- @buf: [in] A piece of userspace memory that contains the
name of @@ -341,25 +339,16 @@ static __poll_t dma_buf_poll(struct file *file, poll_table *poll) static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf) { char *name = strndup_user(buf, DMA_BUF_NAME_LEN);
long ret = 0;
if (IS_ERR(name)) return PTR_ERR(name);
dma_resv_lock(dmabuf->resv, NULL);
if (!list_empty(&dmabuf->attachments)) {
ret = -EBUSY;kfree(name);goto out_unlock;} spin_lock(&dmabuf->name_lock); kfree(dmabuf->name); dmabuf->name = name; spin_unlock(&dmabuf->name_lock);
-out_unlock:
- dma_resv_unlock(dmabuf->resv);
- return ret;
- return 0;
}
static long dma_buf_ioctl(struct file *file,