[PATCH 4.9 36/53] idr: add ida_is_empty

Greg Kroah-Hartman
2021-03-29T08:05:34Z

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

[ Upstream commit 99c494077e2d4282a17120a772eecc00ec3004cc ]

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.

Link: http://lkml.kernel.org/r/1480369871-5271-63-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Konstantin Khlebnikov <koct9i@gmail.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 8e83649f77ce..42e5677d932d 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -932,7 +932,7 @@ 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);
@@ -958,7 +958,7 @@ 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);
@@ -971,7 +971,7 @@ 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 b962f24b500b..b3d036d06553 100644
--- a/drivers/usb/gadget/function/f_printer.c
+++ b/drivers/usb/gadget/function/f_printer.c
@@ -1276,7 +1276,7 @@ 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);
@@ -1300,7 +1300,7 @@ 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);
@@ -1313,7 +1313,7 @@ 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 083d61e92706..3639a28188c9 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__ */
--
2.30.1