Re: [PATCH] Bluetooth: vhci: manage mutex with cleanup helpers

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Aug 13, 2024 at 08:18:28PM +0800, Yo-Jung (Leo) Lin wrote:
> Use macros in liunx/cleanup.h for automatic resource cleanup.

That says what you do, but not _why_ you want to do it.

> 
> Signed-off-by: Yo-Jung (Leo) Lin <0xff07@gmail.com>
> ---
>  drivers/bluetooth/hci_vhci.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c
> index c4046f8f1985..70f0c28372ec 100644
> --- a/drivers/bluetooth/hci_vhci.c
> +++ b/drivers/bluetooth/hci_vhci.c
> @@ -19,6 +19,7 @@
>  #include <linux/errno.h>
>  #include <linux/sched.h>
>  #include <linux/poll.h>
> +#include <linux/cleanup.h>
>  
>  #include <linux/skbuff.h>
>  #include <linux/miscdevice.h>
> @@ -468,9 +469,9 @@ static int vhci_create_device(struct vhci_data *data, __u8 opcode)
>  {
>  	int err;
>  
> -	mutex_lock(&data->open_mutex);
> -	err = __vhci_create_device(data, opcode);
> -	mutex_unlock(&data->open_mutex);
> +	scoped_guard(mutex, &data->open_mutex) {
> +		err = __vhci_create_device(data, opcode);
> +	}

This isn't correct, but also, it's not needed at all :(

greg k-h