Re: [PATCH 23/29] idr: Add ida_is_empty

From: Konstantin Khlebnikov
Date: Fri Nov 18 2016 - 06:56:16 EST


On Thu, Nov 17, 2016 at 3:16 AM, Matthew Wilcox
<mawilcox@xxxxxxxxxxxxxxxxx> wrote:
> From: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
>
> Two of the USB Gadgets were poking around in the internals of struct ida
> in order to determine if it is empty. Add the appropriate abstraction.

Looks good. This could be applied separately.

>
> Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/gadget/function/f_hid.c | 6 +++---
> drivers/usb/gadget/function/f_printer.c | 6 +++---
> include/linux/idr.h | 5 +++++
> 3 files changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
> index e2966f8..b9b04fc 100644
> --- a/drivers/usb/gadget/function/f_hid.c
> +++ b/drivers/usb/gadget/function/f_hid.c
> @@ -840,7 +840,7 @@ static void hidg_free_inst(struct usb_function_instance *f)
> mutex_lock(&hidg_ida_lock);
>
> hidg_put_minor(opts->minor);
> - if (idr_is_empty(&hidg_ida.idr))
> + if (ida_is_empty(&hidg_ida))
> ghid_cleanup();
>
> mutex_unlock(&hidg_ida_lock);
> @@ -866,7 +866,7 @@ static struct usb_function_instance *hidg_alloc_inst(void)
>
> mutex_lock(&hidg_ida_lock);
>
> - if (idr_is_empty(&hidg_ida.idr)) {
> + if (ida_is_empty(&hidg_ida)) {
> status = ghid_setup(NULL, HIDG_MINORS);
> if (status) {
> ret = ERR_PTR(status);
> @@ -879,7 +879,7 @@ static struct usb_function_instance *hidg_alloc_inst(void)
> if (opts->minor < 0) {
> ret = ERR_PTR(opts->minor);
> kfree(opts);
> - if (idr_is_empty(&hidg_ida.idr))
> + if (ida_is_empty(&hidg_ida))
> ghid_cleanup();
> goto unlock;
> }
> diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
> index 0de36cd..8054da9 100644
> --- a/drivers/usb/gadget/function/f_printer.c
> +++ b/drivers/usb/gadget/function/f_printer.c
> @@ -1265,7 +1265,7 @@ static void gprinter_free_inst(struct usb_function_instance *f)
> mutex_lock(&printer_ida_lock);
>
> gprinter_put_minor(opts->minor);
> - if (idr_is_empty(&printer_ida.idr))
> + if (ida_is_empty(&printer_ida))
> gprinter_cleanup();
>
> mutex_unlock(&printer_ida_lock);
> @@ -1289,7 +1289,7 @@ static struct usb_function_instance *gprinter_alloc_inst(void)
>
> mutex_lock(&printer_ida_lock);
>
> - if (idr_is_empty(&printer_ida.idr)) {
> + if (ida_is_empty(&printer_ida)) {
> status = gprinter_setup(PRINTER_MINORS);
> if (status) {
> ret = ERR_PTR(status);
> @@ -1302,7 +1302,7 @@ static struct usb_function_instance *gprinter_alloc_inst(void)
> if (opts->minor < 0) {
> ret = ERR_PTR(opts->minor);
> kfree(opts);
> - if (idr_is_empty(&printer_ida.idr))
> + if (ida_is_empty(&printer_ida))
> gprinter_cleanup();
> goto unlock;
> }
> diff --git a/include/linux/idr.h b/include/linux/idr.h
> index 083d61e..3639a28 100644
> --- a/include/linux/idr.h
> +++ b/include/linux/idr.h
> @@ -195,6 +195,11 @@ static inline int ida_get_new(struct ida *ida, int *p_id)
> return ida_get_new_above(ida, 0, p_id);
> }
>
> +static inline bool ida_is_empty(struct ida *ida)
> +{
> + return idr_is_empty(&ida->idr);
> +}
> +
> void __init idr_init_cache(void);
>
> #endif /* __IDR_H__ */
> --
> 2.10.2
>