* ERR_PTR and PTR_ERR
@ 2010-05-16 8:58 Julia Lawall
2010-05-16 9:05 ` Julia Lawall
0 siblings, 1 reply; 4+ messages in thread
From: Julia Lawall @ 2010-05-16 8:58 UTC (permalink / raw)
To: linux-kernel, kernel-janitors
I see a number of occurrences of code like the following:
if (IS_ERR(alg))
return ERR_PTR(PTR_ERR(alg));
Is there any reason why the second line couldn't just be return alg?
julia
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: ERR_PTR and PTR_ERR
2010-05-16 8:58 ERR_PTR and PTR_ERR Julia Lawall
@ 2010-05-16 9:05 ` Julia Lawall
2010-05-16 17:37 ` Al Viro
0 siblings, 1 reply; 4+ messages in thread
From: Julia Lawall @ 2010-05-16 9:05 UTC (permalink / raw)
To: linux-kernel, kernel-janitors
On Sun, 16 May 2010, Julia Lawall wrote:
> I see a number of occurrences of code like the following:
>
> if (IS_ERR(alg))
> return ERR_PTR(PTR_ERR(alg));
>
> Is there any reason why the second line couldn't just be return alg?
Hmm, never mind. It seems to address a type problem.
julia
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: ERR_PTR and PTR_ERR
2010-05-16 9:05 ` Julia Lawall
@ 2010-05-16 17:37 ` Al Viro
2010-05-16 18:26 ` Julia Lawall
0 siblings, 1 reply; 4+ messages in thread
From: Al Viro @ 2010-05-16 17:37 UTC (permalink / raw)
To: Julia Lawall; +Cc: linux-kernel, kernel-janitors
On Sun, May 16, 2010 at 11:05:23AM +0200, Julia Lawall wrote:
> On Sun, 16 May 2010, Julia Lawall wrote:
>
> > I see a number of occurrences of code like the following:
> >
> > if (IS_ERR(alg))
> > return ERR_PTR(PTR_ERR(alg));
> >
> > Is there any reason why the second line couldn't just be return alg?
>
> Hmm, never mind. It seems to address a type problem.
More idiomatic way to deal with that is ERR_CAST(); see e.g. ext2_lookup() for
use case:
...
inode = NULL;
if (ino) {
inode = ext2_iget(dir->i_sb, ino);
if (unlikely(IS_ERR(inode))) {
if (PTR_ERR(inode) == -ESTALE) {
ext2_error(dir->i_sb, __func__,
"deleted inode referenced: %lu",
(unsigned long) ino);
return ERR_PTR(-EIO);
} else {
return ERR_CAST(inode);
}
}
}
return d_splice_alias(inode, dentry);
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: ERR_PTR and PTR_ERR
2010-05-16 17:37 ` Al Viro
@ 2010-05-16 18:26 ` Julia Lawall
0 siblings, 0 replies; 4+ messages in thread
From: Julia Lawall @ 2010-05-16 18:26 UTC (permalink / raw)
To: Al Viro; +Cc: linux-kernel, kernel-janitors
On Sun, 16 May 2010, Al Viro wrote:
> On Sun, May 16, 2010 at 11:05:23AM +0200, Julia Lawall wrote:
> > On Sun, 16 May 2010, Julia Lawall wrote:
> >
> > > I see a number of occurrences of code like the following:
> > >
> > > if (IS_ERR(alg))
> > > return ERR_PTR(PTR_ERR(alg));
> > >
> > > Is there any reason why the second line couldn't just be return alg?
> >
> > Hmm, never mind. It seems to address a type problem.
>
> More idiomatic way to deal with that is ERR_CAST(); see e.g. ext2_lookup() for
> use case:
Thanks. That looks much nicer than ERR_PTR(PTR_ERR(alg)).
julia
> ...
> inode = NULL;
> if (ino) {
> inode = ext2_iget(dir->i_sb, ino);
> if (unlikely(IS_ERR(inode))) {
> if (PTR_ERR(inode) == -ESTALE) {
> ext2_error(dir->i_sb, __func__,
> "deleted inode referenced: %lu",
> (unsigned long) ino);
> return ERR_PTR(-EIO);
> } else {
> return ERR_CAST(inode);
> }
> }
> }
> return d_splice_alias(inode, dentry);
>
> --
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>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2010-05-16 8:58 ERR_PTR and PTR_ERR Julia Lawall
2010-05-16 9:05 ` Julia Lawall
2010-05-16 17:37 ` Al Viro
2010-05-16 18:26 ` Julia Lawall
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