Re: [PATCH] debugfs: remove unused variable

[Eric Engestrom]

On Wed, Sep 21, 2016 at 10:50:38AM +0200, Nicolai Stange wrote:
> Greg Kroah-Hartman  writes:
> 
> > On Tue, Sep 20, 2016 at 05:17:15PM +0100, Eric Engestrom wrote:
> >> Signed-off-by: Eric Engestrom 
> >> ---
> >>  fs/debugfs/file.c | 3 +--
> >>  1 file changed, 1 insertion(+), 2 deletions(-)
> >> 
> >> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
> >> index 592059f..04eca0b 100644
> >> --- a/fs/debugfs/file.c
> >> +++ b/fs/debugfs/file.c
> >> @@ -195,7 +195,6 @@ static int full_proxy_release(struct inode *inode, 
> >> struct file *filp)
> >>const struct dentry *dentry = F_DENTRY(filp);
> >>const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
> >>const struct file_operations *proxy_fops = filp->f_op;
> >> -  int r = 0;
> >>  
> >>/*
> >> * We must not protect this against removal races here: the
> >> @@ -204,7 +203,7 @@ static int full_proxy_release(struct inode *inode, 
> >> struct file *filp)
> >> * ->i_private is still being meaningful here.
> >> */
> >>if (real_fops->release)
> >> -  r = real_fops->release(inode, filp);
> >> +  real_fops->release(inode, filp);
> >
> > Hm, shouldn't we be propagating the result back up the call chain?
> 
> AFAICS, the VFS layer doesn't ever evaluate the return value of
> ->release(), c.f. __fput() in fs/file_table.c .
> 
> OTOH, propagating that value back to caller also wouldn't hurt. But this
> would be a matter of taste/coding style.

I actually sent an updated fix [1] about an hour ago, which propagates
the result instead (which is better IMO, I don't know why I didn't do
that the first time around).

[1] http://marc.info/?m=147444718118891  (lkml.org is down?)

> 
> I can't remember whether I left this unused int r there on purpose. I
> doubt not. Eric, did you run your patch through sparse and Coccinelle?

I didn't; how do I do that?  I know these tools, but not how to use them
in this context.

Cheers,
  Eric

> 
> If so,
> 
>   Reviewed-by: Nicolai Stange 
> 
> for the diff. (This patch lacks a description though.)
> 
> 
> Thanks,
> 
> Nicolai

Re: [PATCH] debugfs: remove unused variable

[Eric Engestrom]

On Wed, Sep 21, 2016 at 10:50:38AM +0200, Nicolai Stange wrote:
> Greg Kroah-Hartman  writes:
> 
> > On Tue, Sep 20, 2016 at 05:17:15PM +0100, Eric Engestrom wrote:
> >> Signed-off-by: Eric Engestrom 
> >> ---
> >>  fs/debugfs/file.c | 3 +--
> >>  1 file changed, 1 insertion(+), 2 deletions(-)
> >> 
> >> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
> >> index 592059f..04eca0b 100644
> >> --- a/fs/debugfs/file.c
> >> +++ b/fs/debugfs/file.c
> >> @@ -195,7 +195,6 @@ static int full_proxy_release(struct inode *inode, 
> >> struct file *filp)
> >>const struct dentry *dentry = F_DENTRY(filp);
> >>const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
> >>const struct file_operations *proxy_fops = filp->f_op;
> >> -  int r = 0;
> >>  
> >>/*
> >> * We must not protect this against removal races here: the
> >> @@ -204,7 +203,7 @@ static int full_proxy_release(struct inode *inode, 
> >> struct file *filp)
> >> * ->i_private is still being meaningful here.
> >> */
> >>if (real_fops->release)
> >> -  r = real_fops->release(inode, filp);
> >> +  real_fops->release(inode, filp);
> >
> > Hm, shouldn't we be propagating the result back up the call chain?
> 
> AFAICS, the VFS layer doesn't ever evaluate the return value of
> ->release(), c.f. __fput() in fs/file_table.c .
> 
> OTOH, propagating that value back to caller also wouldn't hurt. But this
> would be a matter of taste/coding style.

I actually sent an updated fix [1] about an hour ago, which propagates
the result instead (which is better IMO, I don't know why I didn't do
that the first time around).

[1] http://marc.info/?m=147444718118891  (lkml.org is down?)

> 
> I can't remember whether I left this unused int r there on purpose. I
> doubt not. Eric, did you run your patch through sparse and Coccinelle?

I didn't; how do I do that?  I know these tools, but not how to use them
in this context.

Cheers,
  Eric

> 
> If so,
> 
>   Reviewed-by: Nicolai Stange 
> 
> for the diff. (This patch lacks a description though.)
> 
> 
> Thanks,
> 
> Nicolai

Re: [PATCH] debugfs: remove unused variable

[Nicolai Stange]

Greg Kroah-Hartman  writes:

> On Tue, Sep 20, 2016 at 05:17:15PM +0100, Eric Engestrom wrote:
>> Signed-off-by: Eric Engestrom 
>> ---
>>  fs/debugfs/file.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>> 
>> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
>> index 592059f..04eca0b 100644
>> --- a/fs/debugfs/file.c
>> +++ b/fs/debugfs/file.c
>> @@ -195,7 +195,6 @@ static int full_proxy_release(struct inode *inode, 
>> struct file *filp)
>>  const struct dentry *dentry = F_DENTRY(filp);
>>  const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
>>  const struct file_operations *proxy_fops = filp->f_op;
>> -int r = 0;
>>  
>>  /*
>>   * We must not protect this against removal races here: the
>> @@ -204,7 +203,7 @@ static int full_proxy_release(struct inode *inode, 
>> struct file *filp)
>>   * ->i_private is still being meaningful here.
>>   */
>>  if (real_fops->release)
>> -r = real_fops->release(inode, filp);
>> +real_fops->release(inode, filp);
>
> Hm, shouldn't we be propagating the result back up the call chain?

AFAICS, the VFS layer doesn't ever evaluate the return value of
->release(), c.f. __fput() in fs/file_table.c .

OTOH, propagating that value back to caller also wouldn't hurt. But this
would be a matter of taste/coding style.


I can't remember whether I left this unused int r there on purpose. I
doubt not. Eric, did you run your patch through sparse and Coccinelle?

If so,

  Reviewed-by: Nicolai Stange 

for the diff. (This patch lacks a description though.)


Thanks,

Nicolai

Re: [PATCH] debugfs: remove unused variable

[Nicolai Stange]

Greg Kroah-Hartman  writes:

> On Tue, Sep 20, 2016 at 05:17:15PM +0100, Eric Engestrom wrote:
>> Signed-off-by: Eric Engestrom 
>> ---
>>  fs/debugfs/file.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>> 
>> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
>> index 592059f..04eca0b 100644
>> --- a/fs/debugfs/file.c
>> +++ b/fs/debugfs/file.c
>> @@ -195,7 +195,6 @@ static int full_proxy_release(struct inode *inode, 
>> struct file *filp)
>>  const struct dentry *dentry = F_DENTRY(filp);
>>  const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
>>  const struct file_operations *proxy_fops = filp->f_op;
>> -int r = 0;
>>  
>>  /*
>>   * We must not protect this against removal races here: the
>> @@ -204,7 +203,7 @@ static int full_proxy_release(struct inode *inode, 
>> struct file *filp)
>>   * ->i_private is still being meaningful here.
>>   */
>>  if (real_fops->release)
>> -r = real_fops->release(inode, filp);
>> +real_fops->release(inode, filp);
>
> Hm, shouldn't we be propagating the result back up the call chain?

AFAICS, the VFS layer doesn't ever evaluate the return value of
->release(), c.f. __fput() in fs/file_table.c .

OTOH, propagating that value back to caller also wouldn't hurt. But this
would be a matter of taste/coding style.


I can't remember whether I left this unused int r there on purpose. I
doubt not. Eric, did you run your patch through sparse and Coccinelle?

If so,

  Reviewed-by: Nicolai Stange 

for the diff. (This patch lacks a description though.)


Thanks,

Nicolai

Re: [PATCH] debugfs: remove unused variable

[Eric Engestrom]

On Wed, Sep 21, 2016 at 10:01:11AM +0200, Greg Kroah-Hartman wrote:
> On Tue, Sep 20, 2016 at 05:17:15PM +0100, Eric Engestrom wrote:
> > Signed-off-by: Eric Engestrom 
> > ---
> >  fs/debugfs/file.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
> > index 592059f..04eca0b 100644
> > --- a/fs/debugfs/file.c
> > +++ b/fs/debugfs/file.c
> > @@ -195,7 +195,6 @@ static int full_proxy_release(struct inode *inode, 
> > struct file *filp)
> > const struct dentry *dentry = F_DENTRY(filp);
> > const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
> > const struct file_operations *proxy_fops = filp->f_op;
> > -   int r = 0;
> >  
> > /*
> >  * We must not protect this against removal races here: the
> > @@ -204,7 +203,7 @@ static int full_proxy_release(struct inode *inode, 
> > struct file *filp)
> >  * ->i_private is still being meaningful here.
> >  */
> > if (real_fops->release)
> > -   r = real_fops->release(inode, filp);
> > +   real_fops->release(inode, filp);
> 
> Hm, shouldn't we be propagating the result back up the call chain?

You're right, sorry, I wasn't thinking. Correct fix incoming :)

Cheers,
  Eric

> 
> thanks,
> 
> greg k-h

Re: [PATCH] debugfs: remove unused variable

[Eric Engestrom]

On Wed, Sep 21, 2016 at 10:01:11AM +0200, Greg Kroah-Hartman wrote:
> On Tue, Sep 20, 2016 at 05:17:15PM +0100, Eric Engestrom wrote:
> > Signed-off-by: Eric Engestrom 
> > ---
> >  fs/debugfs/file.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
> > index 592059f..04eca0b 100644
> > --- a/fs/debugfs/file.c
> > +++ b/fs/debugfs/file.c
> > @@ -195,7 +195,6 @@ static int full_proxy_release(struct inode *inode, 
> > struct file *filp)
> > const struct dentry *dentry = F_DENTRY(filp);
> > const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
> > const struct file_operations *proxy_fops = filp->f_op;
> > -   int r = 0;
> >  
> > /*
> >  * We must not protect this against removal races here: the
> > @@ -204,7 +203,7 @@ static int full_proxy_release(struct inode *inode, 
> > struct file *filp)
> >  * ->i_private is still being meaningful here.
> >  */
> > if (real_fops->release)
> > -   r = real_fops->release(inode, filp);
> > +   real_fops->release(inode, filp);
> 
> Hm, shouldn't we be propagating the result back up the call chain?

You're right, sorry, I wasn't thinking. Correct fix incoming :)

Cheers,
  Eric

> 
> thanks,
> 
> greg k-h

Re: [PATCH] debugfs: remove unused variable

[Greg Kroah-Hartman]

On Tue, Sep 20, 2016 at 05:17:15PM +0100, Eric Engestrom wrote:
> Signed-off-by: Eric Engestrom 
> ---
>  fs/debugfs/file.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
> index 592059f..04eca0b 100644
> --- a/fs/debugfs/file.c
> +++ b/fs/debugfs/file.c
> @@ -195,7 +195,6 @@ static int full_proxy_release(struct inode *inode, struct 
> file *filp)
>   const struct dentry *dentry = F_DENTRY(filp);
>   const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
>   const struct file_operations *proxy_fops = filp->f_op;
> - int r = 0;
>  
>   /*
>* We must not protect this against removal races here: the
> @@ -204,7 +203,7 @@ static int full_proxy_release(struct inode *inode, struct 
> file *filp)
>* ->i_private is still being meaningful here.
>*/
>   if (real_fops->release)
> - r = real_fops->release(inode, filp);
> + real_fops->release(inode, filp);

Hm, shouldn't we be propagating the result back up the call chain?

thanks,

greg k-h

Re: [PATCH] debugfs: remove unused variable

[Greg Kroah-Hartman]

On Tue, Sep 20, 2016 at 05:17:15PM +0100, Eric Engestrom wrote:
> Signed-off-by: Eric Engestrom 
> ---
>  fs/debugfs/file.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
> index 592059f..04eca0b 100644
> --- a/fs/debugfs/file.c
> +++ b/fs/debugfs/file.c
> @@ -195,7 +195,6 @@ static int full_proxy_release(struct inode *inode, struct 
> file *filp)
>   const struct dentry *dentry = F_DENTRY(filp);
>   const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
>   const struct file_operations *proxy_fops = filp->f_op;
> - int r = 0;
>  
>   /*
>* We must not protect this against removal races here: the
> @@ -204,7 +203,7 @@ static int full_proxy_release(struct inode *inode, struct 
> file *filp)
>* ->i_private is still being meaningful here.
>*/
>   if (real_fops->release)
> - r = real_fops->release(inode, filp);
> + real_fops->release(inode, filp);

Hm, shouldn't we be propagating the result back up the call chain?

thanks,

greg k-h

[PATCH] debugfs: remove unused variable

[Eric Engestrom]

Signed-off-by: Eric Engestrom 
---
 fs/debugfs/file.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 592059f..04eca0b 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -195,7 +195,6 @@ static int full_proxy_release(struct inode *inode, struct 
file *filp)
const struct dentry *dentry = F_DENTRY(filp);
const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
const struct file_operations *proxy_fops = filp->f_op;
-   int r = 0;
 
/*
 * We must not protect this against removal races here: the
@@ -204,7 +203,7 @@ static int full_proxy_release(struct inode *inode, struct 
file *filp)
 * ->i_private is still being meaningful here.
 */
if (real_fops->release)
-   r = real_fops->release(inode, filp);
+   real_fops->release(inode, filp);
 
replace_fops(filp, d_inode(dentry)->i_fop);
kfree((void *)proxy_fops);
-- 
Cheers,
  Eric

[PATCH] debugfs: remove unused variable

[Eric Engestrom]

Signed-off-by: Eric Engestrom 
---
 fs/debugfs/file.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 592059f..04eca0b 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -195,7 +195,6 @@ static int full_proxy_release(struct inode *inode, struct 
file *filp)
const struct dentry *dentry = F_DENTRY(filp);
const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
const struct file_operations *proxy_fops = filp->f_op;
-   int r = 0;
 
/*
 * We must not protect this against removal races here: the
@@ -204,7 +203,7 @@ static int full_proxy_release(struct inode *inode, struct 
file *filp)
 * ->i_private is still being meaningful here.
 */
if (real_fops->release)
-   r = real_fops->release(inode, filp);
+   real_fops->release(inode, filp);
 
replace_fops(filp, d_inode(dentry)->i_fop);
kfree((void *)proxy_fops);
-- 
Cheers,
  Eric