On 2/12/19 3:36 PM, Jens Axboe wrote:
> On 2/12/19 2:28 PM, Gustavo A. R. Silva wrote:
>> In preparation to enabling -Wimplicit-fallthrough, mark switch
>> cases where we are expecting to fall through.
>>
>> This patch fixes the following warnings:
>>
>> drivers/block/drbd/drbd_receiver.c: In function ‘drbd_asb_recover_0p’:
>> drivers/block/drbd/drbd_receiver.c:3093:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>> if (self == 1 && peer == 0) {
>> ^
>> drivers/block/drbd/drbd_receiver.c:3098:2: note: here
>> case ASB_DISCARD_OLDER_PRI:
>> ^~~~
>> drivers/block/drbd/drbd_receiver.c:3120:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>> if (after_sb_0p == ASB_DISCARD_ZERO_CHG)
>> ^
>> drivers/block/drbd/drbd_receiver.c:3123:2: note: here
>> case ASB_DISCARD_LEAST_CHG:
>> ^~~~
>>
>> Warning level 3 was used: -Wimplicit-fallthrough=3
>>
>> Notice that in some cases, the code comment is modified in
>> accordance with what GCC is expecting to find.
>>
>> This patch is part of the ongoing efforts to enable
>> -Wimplicit-fallthrough.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
>> ---
>> drivers/block/drbd/drbd_receiver.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
>> index c7ad88d91a09..78bb763a367d 100644
>> --- a/drivers/block/drbd/drbd_receiver.c
>> +++ b/drivers/block/drbd/drbd_receiver.c
>> @@ -3094,7 +3094,7 @@ static int drbd_asb_recover_0p(struct drbd_peer_device *peer_device) __must_hold
>> rv = 1;
>> break;
>> }
>> - /* Else fall through to one of the other strategies... */
>> + /* Else fall through - to one of the other strategies... */
>> case ASB_DISCARD_OLDER_PRI:
>> if (self == 0 && peer == 1) {
>> rv = 1;
>> @@ -3119,7 +3119,7 @@ static int drbd_asb_recover_0p(struct drbd_peer_device *peer_device) __must_hold
>> }
>> if (after_sb_0p == ASB_DISCARD_ZERO_CHG)
>> break;
>> - /* else: fall through */
>> + /* Else fall through */
>
> This is getting really silly, as these two hunks both aptly demonstrate. Can
> we please inject some sanity into this fall through witch hunt?
>
No witch hunt here. This work has proved to be very valuable. I've fixed years-old
bugs thanks to this effort.
> The last hunk is updating ANOTHER patch that also attempted to silence this
> stuff.
>
Yeah. Sorry about that.
Previously, I was using level 2: -Wimplicit-fallthrough=2, but this time I'm
using level 3: -Wimplicit-fallthrough=3, which is stricter and maps to -Wextra.
Thanks
--
Gustavo
