[PATCH 23/29] idr: Add ida_is_empty

[Matthew Wilcox]

From: Matthew Wilcox <wi...@linux.intel.com>

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.

Signed-off-by: Matthew Wilcox <wi...@linux.intel.com>
---
 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