rbd: add missing return statements
diff mbox

Message ID 20180404094931.2345742-1-arnd@arndb.de
State New
Headers show

Commit Message

Arnd Bergmann April 4, 2018, 9:49 a.m. UTC
A new set of warnings appeared in next-20180403 in some configurations
when gcc cannot see that rbd_assert(0) leads to an unreachable code
path:

drivers/block/rbd.c: In function 'rbd_img_is_write':
drivers/block/rbd.c:1397:1: error: control reaches end of non-void function [-Werror=return-type]
drivers/block/rbd.c: In function '__rbd_obj_handle_request':
drivers/block/rbd.c:2499:1: error: control reaches end of non-void function [-Werror=return-type]
drivers/block/rbd.c: In function 'rbd_obj_handle_write':
drivers/block/rbd.c:2471:1: error: control reaches end of non-void function [-Werror=return-type]

To work around this, we can add a return statement to each of these
cases. An alternative would be to remove the unlikely() annotation
in rbd_assert(), or to just use BUG()/BUG_ON() directly. This adds the
return statements, guessing what the most reasonable behavior
would be.

Fixes: 3da691bf4366 ("rbd: new request handling code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/block/rbd.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Ilya Dryomov April 4, 2018, 11:04 a.m. UTC | #1
On Wed, Apr 4, 2018 at 11:49 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> A new set of warnings appeared in next-20180403 in some configurations
> when gcc cannot see that rbd_assert(0) leads to an unreachable code
> path:
>
> drivers/block/rbd.c: In function 'rbd_img_is_write':
> drivers/block/rbd.c:1397:1: error: control reaches end of non-void function [-Werror=return-type]
> drivers/block/rbd.c: In function '__rbd_obj_handle_request':
> drivers/block/rbd.c:2499:1: error: control reaches end of non-void function [-Werror=return-type]
> drivers/block/rbd.c: In function 'rbd_obj_handle_write':
> drivers/block/rbd.c:2471:1: error: control reaches end of non-void function [-Werror=return-type]
>
> To work around this, we can add a return statement to each of these
> cases. An alternative would be to remove the unlikely() annotation
> in rbd_assert(), or to just use BUG()/BUG_ON() directly. This adds the
> return statements, guessing what the most reasonable behavior
> would be.

Hi Arnd,

I don't like these bogus return statements.  Let's go with explicit
BUG/BUG_ON() instead.

Thanks,

                Ilya
--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Arnd Bergmann April 4, 2018, 12:54 p.m. UTC | #2
On Wed, Apr 4, 2018 at 1:04 PM, Ilya Dryomov <idryomov@gmail.com> wrote:
> On Wed, Apr 4, 2018 at 11:49 AM, Arnd Bergmann <arnd@arndb.de> wrote:
>> A new set of warnings appeared in next-20180403 in some configurations
>> when gcc cannot see that rbd_assert(0) leads to an unreachable code
>> path:
>>
>> drivers/block/rbd.c: In function 'rbd_img_is_write':
>> drivers/block/rbd.c:1397:1: error: control reaches end of non-void function [-Werror=return-type]
>> drivers/block/rbd.c: In function '__rbd_obj_handle_request':
>> drivers/block/rbd.c:2499:1: error: control reaches end of non-void function [-Werror=return-type]
>> drivers/block/rbd.c: In function 'rbd_obj_handle_write':
>> drivers/block/rbd.c:2471:1: error: control reaches end of non-void function [-Werror=return-type]
>>
>> To work around this, we can add a return statement to each of these
>> cases. An alternative would be to remove the unlikely() annotation
>> in rbd_assert(), or to just use BUG()/BUG_ON() directly. This adds the
>> return statements, guessing what the most reasonable behavior
>> would be.
>
> Hi Arnd,
>
> I don't like these bogus return statements.  Let's go with explicit
> BUG/BUG_ON() instead.

Sounds good. Sent a v2 now.

       Arnd
--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch
diff mbox

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 07dc5419bd63..9445a71a9cd6 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1394,6 +1394,7 @@  static bool rbd_img_is_write(struct rbd_img_request *img_req)
 	default:
 		rbd_assert(0);
 	}
+	return false;
 }
 
 static void rbd_obj_handle_request(struct rbd_obj_request *obj_req);
@@ -2468,6 +2469,7 @@  static bool rbd_obj_handle_write(struct rbd_obj_request *obj_req)
 	default:
 		rbd_assert(0);
 	}
+	return true;
 }
 
 /*
@@ -2496,6 +2498,7 @@  static bool __rbd_obj_handle_request(struct rbd_obj_request *obj_req)
 	default:
 		rbd_assert(0);
 	}
+	return true;
 }
 
 static void rbd_obj_end_request(struct rbd_obj_request *obj_req)