On Thu, Feb 2, 2023 at 9:00 AM Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
>
> Clang warns:
>
> ../drivers/md/dm-flakey.c:369:28: error: equality comparison with extraneous parentheses [-Werror,-Wparentheses-equality]
> if ((fc->corrupt_bio_rw == WRITE)) {
> ~~~~~~~~~~~~~~~~~~~^~~~~~~~
> ../drivers/md/dm-flakey.c:369:28: note: remove extraneous parentheses around the comparison to silence this warning
> if ((fc->corrupt_bio_rw == WRITE)) {
> ~ ^ ~
> ../drivers/md/dm-flakey.c:369:28: note: use '=' to turn this equality comparison into an assignment
> if ((fc->corrupt_bio_rw == WRITE)) {
> ^~
> =
> 1 error generated.
>
> GCC only warns when one set of parentheses are used for assignment
> expressions, whereas clang additionally warns when two sets of
> parentheses are used for equality comparisons. Remove the extra set of
> parentheses to silence the warning as it suggests, as this is obviously
> supposed to be an equality comparison.
>
> Fixes: 0e766389cedc ("dm flakey: fix logic when corrupting a bio")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1798
> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> ---
> I do not mind this change being squashed with the offending commit, as I
> noticed it was Cc'd for stable, which would minimize the chance for
> breakage.
> ---
> drivers/md/dm-flakey.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
> index 08f9aa476d97..335684a1aeaa 100644
> --- a/drivers/md/dm-flakey.c
> +++ b/drivers/md/dm-flakey.c
> @@ -366,7 +366,7 @@ static int flakey_map(struct dm_target *ti, struct bio *bio)
> * Corrupt matching writes.
> */
> if (fc->corrupt_bio_byte) {
> - if ((fc->corrupt_bio_rw == WRITE)) {
> + if (fc->corrupt_bio_rw == WRITE) {
> if (all_corrupt_bio_flags_match(bio, fc))
> corrupt_bio_data(bio, fc);
> }
>
> ---
> base-commit: 6f30cc248507ee96c22ff4c3cbc86099ff12b7a9
> change-id: 20230202-dm-parenthesis-warning-6139f4b5020b
>
> Best regards,
> --
> Nathan Chancellor <nathan@xxxxxxxxxx>
>
--
Thanks,
~Nick Desaulniers
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