From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: [PATCH] md: fix a build warning Date: Thu, 11 Jun 2015 06:38:26 +1000 Message-ID: <20150611063826.78ea7931@home.neil.brown.name> References: <1433949658-8455-1-git-send-email-firogm@gmail.com> <557874B9.9010500@bfs.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Julia Lawall Cc: walter harms , Firo Yang , linux-raid@vger.kernel.org, kernel-janitors@vger.kernel.org List-Id: linux-raid.ids On Wed, 10 Jun 2015 19:36:43 +0200 (CEST) Julia Lawall wrote: >=20 >=20 > On Wed, 10 Jun 2015, walter harms wrote: >=20 > > > > > > Am 10.06.2015 17:20, schrieb Firo Yang: > > > Warning like this: > > > > > > drivers/md/md.c: In function =E2=80=98update_array_info=E2=80=99: > > > drivers/md/md.c:6394:26: warning: logical not is only applied > > > to the left hand side of comparison [-Wlogical-not-parentheses] > > > !mddev->persistent !=3D info->not_persistent|| > > > > > > I fix it by enclosing !mddev->persistent with parentheses > > > > > > By the way, I also fixed a line over 80 characters warning output= ed > > > by ./scripts/checkpatch.pl > > > > > > Signed-off-by: Firo Yang > > > --- > > > drivers/md/md.c | 5 +++-- > > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/md/md.c b/drivers/md/md.c > > > index dd85be9..b420d82 100644 > > > --- a/drivers/md/md.c > > > +++ b/drivers/md/md.c > > > @@ -6391,9 +6391,10 @@ static int update_array_info(struct mddev = *mddev, mdu_array_info_t *info) > > > mddev->ctime !=3D info->ctime || > > > mddev->level !=3D info->level || > > > /* mddev->layout !=3D info->layout || */ > > > - !mddev->persistent !=3D info->not_persistent|| > > > + (!mddev->persistent) !=3D info->not_persistent || > > > > > > this looks odd, > > would it be possible the check for =3D=3D instead (and drop the !) = ? > > and it someone care for readability: It would be helpful to > > make some more ifs here. >=20 > The original issue looks like a false positive. If all of the other = cases > have no parentheses on the left and use !=3D, isn't it better to leav= e the > code as is? >=20 Leaving the code as it is would leave at least one compiler generating = warnings. I don't like warnings. So if the compiler can be "fixed" that would be good. But it seems unl= ikely. May we could do: > > > + mddev->persistent !=3D !info->not_persistent || That would keep the two "not"s together, avoid the need for parentheses= , and probably avoid the compiler warning. (I think I had it the way it is because it almost reads=20 " not ...peristent !=3D ... not_persistent" but that isn't a strong reason) =46iro: Can you confirm that this version doesn't upset the compiler? If if doesn't I'd definitely prefer this one. (and definitely leave out= the comment change - just change the code) Thanks, NeilBrown > julia >=20 > > > > re, > > wh > > > > > mddev->chunk_sectors !=3D info->chunk_size >> 9 || > > > - /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESE= NT to change */ > > > + /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESE= NT > > > + to change */ > > > ((state^info->state) & 0xfffffe00) > > > ) > > > return -EINVAL; > > -- > > To unsubscribe from this list: send the line "unsubscribe kernel-ja= nitors" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html