[PATCH] md: fix a build warning

[PATCH] md: fix a build warning

[Firo Yang]

Warning like this:

drivers/md/md.c: In function ‘update_array_info’:
drivers/md/md.c:6394:26: warning: logical not is only applied
to the left hand side of comparison [-Wlogical-not-parentheses]
      !mddev->persistent  != info->not_persistent||

I fix it by enclosing !mddev->persistent with parentheses

By the way, I also fixed a line over 80 characters warning outputed
by ./scripts/checkpatch.pl

Signed-off-by: Firo Yang <firogm@gmail.com>
---
 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         != info->ctime         ||
 	    mddev->level         != info->level         ||
 /*	    mddev->layout        != info->layout        || */
-	    !mddev->persistent	 != info->not_persistent||
+	    (!mddev->persistent) != info->not_persistent ||
 	    mddev->chunk_sectors != info->chunk_size >> 9 ||
-	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
+	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT
+		to change */
 	    ((state^info->state) & 0xfffffe00)
 		)
 		return -EINVAL;
-- 
2.4.2

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Re: [PATCH] md: fix a build warning

[Dan Carpenter]

On Wed, Jun 10, 2015 at 11:20:58PM +0800, Firo Yang wrote:
> By the way, I also fixed a line over 80 characters warning outputed
> by ./scripts/checkpatch.pl

Don't do this.  It's not on the same line, it's not really related at
all.

>  	    mddev->chunk_sectors != info->chunk_size >> 9 ||
> -	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
> +	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT
> +		to change */

The new comment style isn't correct.

regards,
dan carpenter

Re: [PATCH] md: fix a build warning

[walter harms]

Am 10.06.2015 17:20, schrieb Firo Yang:
> Warning like this:
> 
> drivers/md/md.c: In function ‘update_array_info’:
> drivers/md/md.c:6394:26: warning: logical not is only applied
> to the left hand side of comparison [-Wlogical-not-parentheses]
>       !mddev->persistent  != info->not_persistent||
> 
> I fix it by enclosing !mddev->persistent with parentheses
> 
> By the way, I also fixed a line over 80 characters warning outputed
> by ./scripts/checkpatch.pl
> 
> Signed-off-by: Firo Yang <firogm@gmail.com>
> ---
>  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         != info->ctime         ||
>  	    mddev->level         != info->level         ||
>  /*	    mddev->layout        != info->layout        || */
> -	    !mddev->persistent	 != info->not_persistent||
> +	    (!mddev->persistent) != info->not_persistent ||


this looks odd,
would it be possible the check for == instead (and drop the !) ?
and it someone care for readability: It would be helpful to
make some more ifs here.

re,
 wh

>  	    mddev->chunk_sectors != info->chunk_size >> 9 ||
> -	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
> +	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT
> +		to change */
>  	    ((state^info->state) & 0xfffffe00)
>  		)
>  		return -EINVAL;
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Re: [PATCH] md: fix a build warning

[Julia Lawall]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 2098 bytes --]



On Wed, 10 Jun 2015, walter harms wrote:

>
>
> Am 10.06.2015 17:20, schrieb Firo Yang:
> > Warning like this:
> >
> > drivers/md/md.c: In function ‘update_array_info’:
> > drivers/md/md.c:6394:26: warning: logical not is only applied
> > to the left hand side of comparison [-Wlogical-not-parentheses]
> >       !mddev->persistent  != info->not_persistent||
> >
> > I fix it by enclosing !mddev->persistent with parentheses
> >
> > By the way, I also fixed a line over 80 characters warning outputed
> > by ./scripts/checkpatch.pl
> >
> > Signed-off-by: Firo Yang <firogm@gmail.com>
> > ---
> >  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         != info->ctime         ||
> >  	    mddev->level         != info->level         ||
> >  /*	    mddev->layout        != info->layout        || */
> > -	    !mddev->persistent	 != info->not_persistent||
> > +	    (!mddev->persistent) != info->not_persistent ||
>
>
> this looks odd,
> would it be possible the check for == instead (and drop the !) ?
> and it someone care for readability: It would be helpful to
> make some more ifs here.

The original issue looks like a false positive.  If all of the other cases
have no parentheses on the left and use !=, isn't it better to leave the
code as is?

julia

>
> re,
>  wh
>
> >  	    mddev->chunk_sectors != info->chunk_size >> 9 ||
> > -	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
> > +	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT
> > +		to change */
> >  	    ((state^info->state) & 0xfffffe00)
> >  		)
> >  		return -EINVAL;
> --
> To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Re: [PATCH] md: fix a build warning

[walter harms]

Am 10.06.2015 19:36, schrieb Julia Lawall:
> 
> 
> On Wed, 10 Jun 2015, walter harms wrote:
> 
>>
>>
>> Am 10.06.2015 17:20, schrieb Firo Yang:
>>> Warning like this:
>>>
>>> drivers/md/md.c: In function ‘update_array_info’:
>>> drivers/md/md.c:6394:26: warning: logical not is only applied
>>> to the left hand side of comparison [-Wlogical-not-parentheses]
>>>       !mddev->persistent  != info->not_persistent||
>>>
>>> I fix it by enclosing !mddev->persistent with parentheses
>>>
>>> By the way, I also fixed a line over 80 characters warning outputed
>>> by ./scripts/checkpatch.pl
>>>
>>> Signed-off-by: Firo Yang <firogm@gmail.com>
>>> ---
>>>  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         != info->ctime         ||
>>>  	    mddev->level         != info->level         ||
>>>  /*	    mddev->layout        != info->layout        || */
>>> -	    !mddev->persistent	 != info->not_persistent||
>>> +	    (!mddev->persistent) != info->not_persistent ||
>>
>>
>> this looks odd,
>> would it be possible the check for == instead (and drop the !) ?
>> and it someone care for readability: It would be helpful to
>> make some more ifs here.
> 
> The original issue looks like a false positive.  If all of the other cases
> have no parentheses on the left and use !=, isn't it better to leave the
> code as is?
> 

i do not think so, the name indicate persistent/not_persistent devices.
Maybe both parties can agree what should be stored, ppl are bad
at those not_not things and that is an unnecessary trouble spot.

re,
 wh


> julia
> 
>>
>> re,
>>  wh
>>
>>>  	    mddev->chunk_sectors != info->chunk_size >> 9 ||
>>> -	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
>>> +	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT
>>> +		to change */
>>>  	    ((state^info->state) & 0xfffffe00)
>>>  		)
>>>  		return -EINVAL;
>> --
>> To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
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Re: [PATCH] md: fix a build warning

[Neil Brown]

On Wed, 10 Jun 2015 19:36:43 +0200 (CEST)
Julia Lawall <julia.lawall@lip6.fr> wrote:

> 
> 
> On Wed, 10 Jun 2015, walter harms wrote:
> 
> >
> >
> > Am 10.06.2015 17:20, schrieb Firo Yang:
> > > Warning like this:
> > >
> > > drivers/md/md.c: In function ‘update_array_info’:
> > > drivers/md/md.c:6394:26: warning: logical not is only applied
> > > to the left hand side of comparison [-Wlogical-not-parentheses]
> > >       !mddev->persistent  != info->not_persistent||
> > >
> > > I fix it by enclosing !mddev->persistent with parentheses
> > >
> > > By the way, I also fixed a line over 80 characters warning outputed
> > > by ./scripts/checkpatch.pl
> > >
> > > Signed-off-by: Firo Yang <firogm@gmail.com>
> > > ---
> > >  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         != info->ctime         ||
> > >  	    mddev->level         != info->level         ||
> > >  /*	    mddev->layout        != info->layout        || */
> > > -	    !mddev->persistent	 != info->not_persistent||
> > > +	    (!mddev->persistent) != info->not_persistent ||
> >
> >
> > this looks odd,
> > would it be possible the check for == instead (and drop the !) ?
> > and it someone care for readability: It would be helpful to
> > make some more ifs here.
> 
> The original issue looks like a false positive.  If all of the other cases
> have no parentheses on the left and use !=, isn't it better to leave the
> code as is?
> 

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 unlikely.

May we could do:

> > > +	    mddev->persistent != !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 
   " not ...peristent != ... not_persistent"
but that isn't a strong reason)

Firo: 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
> 
> >
> > re,
> >  wh
> >
> > >  	    mddev->chunk_sectors != info->chunk_size >> 9 ||
> > > -	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
> > > +	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT
> > > +		to change */
> > >  	    ((state^info->state) & 0xfffffe00)
> > >  		)
> > >  		return -EINVAL;
> > --
> > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >
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Re: [PATCH] md: fix a build warning

[Neil Brown]

On Wed, 10 Jun 2015 19:32:41 +0200
walter harms <wharms@bfs.de> wrote:

> 
> 
> Am 10.06.2015 17:20, schrieb Firo Yang:
> > Warning like this:
> > 
> > drivers/md/md.c: In function ‘update_array_info’:
> > drivers/md/md.c:6394:26: warning: logical not is only applied
> > to the left hand side of comparison [-Wlogical-not-parentheses]
> >       !mddev->persistent  != info->not_persistent||
> > 
> > I fix it by enclosing !mddev->persistent with parentheses
> > 
> > By the way, I also fixed a line over 80 characters warning outputed
> > by ./scripts/checkpatch.pl
> > 
> > Signed-off-by: Firo Yang <firogm@gmail.com>
> > ---
> >  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         != info->ctime         ||
> >  	    mddev->level         != info->level         ||
> >  /*	    mddev->layout        != info->layout        || */
> > -	    !mddev->persistent	 != info->not_persistent||
> > +	    (!mddev->persistent) != info->not_persistent ||
> 
> 
> this looks odd,
> would it be possible the check for == instead (and drop the !) ?
> and it someone care for readability: It would be helpful to
> make some more ifs here.

The first attempt Firo summited did exactly that.  I said no.
I like the visual consistency of  LHS != RHS.

More 'if's would just waste more vertical space.

Thanks,
NeilBrown

> 
> re,
>  wh
> 
> >  	    mddev->chunk_sectors != info->chunk_size >> 9 ||
> > -	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
> > +	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT
> > +		to change */
> >  	    ((state^info->state) & 0xfffffe00)
> >  		)
> >  		return -EINVAL;

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Re: [PATCH] md: fix a build warning

[Dan Carpenter]

Hey Joe,

checkpatch.pl in linux-next is now encouraging people to make unrelated
long line fixes like the below patch.  Reverting 0b4193c79c83
('checkpatch: categorize some long line length checks') makes the new
checkpatch.pl warning go away.

regards,
dan carpenter

On Wed, Jun 10, 2015 at 11:20:58PM +0800, Firo Yang wrote:
> Warning like this:
> 
> drivers/md/md.c: In function ‘update_array_info’:
> drivers/md/md.c:6394:26: warning: logical not is only applied
> to the left hand side of comparison [-Wlogical-not-parentheses]
>       !mddev->persistent  != info->not_persistent||
> 
> I fix it by enclosing !mddev->persistent with parentheses
> 
> By the way, I also fixed a line over 80 characters warning outputed
> by ./scripts/checkpatch.pl
> 
> Signed-off-by: Firo Yang <firogm@gmail.com>
> ---
>  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         != info->ctime         ||
>  	    mddev->level         != info->level         ||
>  /*	    mddev->layout        != info->layout        || */
> -	    !mddev->persistent	 != info->not_persistent||
> +	    (!mddev->persistent) != info->not_persistent ||
>  	    mddev->chunk_sectors != info->chunk_size >> 9 ||
> -	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
> +	    /* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT
> +		to change */
>  	    ((state^info->state) & 0xfffffe00)
>  		)
>  		return -EINVAL;
> -- 
> 2.4.2
> 
> --
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