[PATCH] fs: stub out ioprio_check_cap for !CONFIG_BLOCK

[Arnd Bergmann]

When CONFIG_BLOCK is disabled, we now run into a link error:

fs/aio.o: In function `aio_prep_rw':
aio.c:(.text+0xf68): undefined reference to `ioprio_check_cap'

Since the priorities are unused without block devices, this adds a stub
that always returns success.

Fixes: d9a08a9e616b ("fs: Add aio iopriority support")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
Not sure if my assertion is correct, please check that returning zero
actually makes sense here.
---
 include/linux/ioprio.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h
index 4a28cec49ec3..ccc2a44483b6 100644
--- a/include/linux/ioprio.h
+++ b/include/linux/ioprio.h
@@ -77,6 +77,13 @@ extern int ioprio_best(unsigned short aprio, unsigned short bprio);
 
 extern int set_task_ioprio(struct task_struct *task, int ioprio);
 
+#ifdef CONFIG_BLOCK
 extern int ioprio_check_cap(int ioprio);
+#else
+static inline int ioprio_check_cap(int ioprio)
+{
+	return 0;
+}
+#endif
 
 #endif
-- 
2.9.0