[PATCH] io_uring: parenthesize io_ring_head_to_buf() expansion

[PATCH] io_uring: parenthesize io_ring_head_to_buf() expansion

[Yi Xie]

Wrap the io_ring_head_to_buf() macro value in an extra pair of parentheses
so it is safe when composed into larger expressions, and to satisfy
scripts/checkpatch.pl.

Signed-off-by: Yi Xie <xieyi@kylinos.cn>
---
 io_uring/kbuf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
index 63061aa1cab9..dd54e43e9ddf 100644
--- a/io_uring/kbuf.c
+++ b/io_uring/kbuf.c
@@ -21,7 +21,7 @@
 #define MAX_BIDS_PER_BGID (1 << 16)
 
 /* Mapped buffer ring, return io_uring_buf from head */
-#define io_ring_head_to_buf(br, head, mask)	&(br)->bufs[(head) & (mask)]
+#define io_ring_head_to_buf(br, head, mask)	(&(br)->bufs[(head) & (mask)])
 
 struct io_provide_buf {
 	struct file			*file;

Re: [PATCH] io_uring: parenthesize io_ring_head_to_buf() expansion

[Jens Axboe]

On Thu, 14 May 2026 16:34:43 +0800, Yi Xie wrote:
> Wrap the io_ring_head_to_buf() macro value in an extra pair of parentheses
> so it is safe when composed into larger expressions, and to satisfy
> scripts/checkpatch.pl.

Applied, thanks!

[1/1] io_uring: parenthesize io_ring_head_to_buf() expansion
      commit: c84701cfc90a90a6a9dfbdb138706a6d79f5b186

Best regards,
-- 
Jens Axboe

Re: [PATCH] io_uring: parenthesize io_ring_head_to_buf() expansion

[Caleb Sander Mateos]

On Thu, May 14, 2026 at 1:35 AM Yi Xie <xieyi@kylinos.cn> wrote:
>
> Wrap the io_ring_head_to_buf() macro value in an extra pair of parentheses
> so it is safe when composed into larger expressions, and to satisfy
> scripts/checkpatch.pl.
>
> Signed-off-by: Yi Xie <xieyi@kylinos.cn>
> ---
>  io_uring/kbuf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
> index 63061aa1cab9..dd54e43e9ddf 100644
> --- a/io_uring/kbuf.c
> +++ b/io_uring/kbuf.c
> @@ -21,7 +21,7 @@
>  #define MAX_BIDS_PER_BGID (1 << 16)
>
>  /* Mapped buffer ring, return io_uring_buf from head */
> -#define io_ring_head_to_buf(br, head, mask)    &(br)->bufs[(head) & (mask)]
> +#define io_ring_head_to_buf(br, head, mask)    (&(br)->bufs[(head) & (mask)])

Is there a reason this can't just be an inline function?

Best,
Caleb

>
>  struct io_provide_buf {
>         struct file                     *file;
>

Re: [PATCH] io_uring: parenthesize io_ring_head_to_buf() expansion

[Jens Axboe]

On 5/14/26 8:22 AM, Caleb Sander Mateos wrote:
> On Thu, May 14, 2026 at 1:35?AM Yi Xie <xieyi@kylinos.cn> wrote:
>>
>> Wrap the io_ring_head_to_buf() macro value in an extra pair of parentheses
>> so it is safe when composed into larger expressions, and to satisfy
>> scripts/checkpatch.pl.
>>
>> Signed-off-by: Yi Xie <xieyi@kylinos.cn>
>> ---
>>  io_uring/kbuf.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
>> index 63061aa1cab9..dd54e43e9ddf 100644
>> --- a/io_uring/kbuf.c
>> +++ b/io_uring/kbuf.c
>> @@ -21,7 +21,7 @@
>>  #define MAX_BIDS_PER_BGID (1 << 16)
>>
>>  /* Mapped buffer ring, return io_uring_buf from head */
>> -#define io_ring_head_to_buf(br, head, mask)    &(br)->bufs[(head) & (mask)]
>> +#define io_ring_head_to_buf(br, head, mask)    (&(br)->bufs[(head) & (mask)])
> 
> Is there a reason this can't just be an inline function?

No reason at all. But also don't see a strong reason why it can't just
be a define. And generally I don't like cleanups like this, but this one
at least made sense to me.

-- 
Jens Axboe

Re: [PATCH] io_uring: parenthesize io_ring_head_to_buf() expansion

[Caleb Sander Mateos]

On Thu, May 14, 2026 at 7:25 AM Jens Axboe <axboe@kernel.dk> wrote:
>
> On 5/14/26 8:22 AM, Caleb Sander Mateos wrote:
> > On Thu, May 14, 2026 at 1:35?AM Yi Xie <xieyi@kylinos.cn> wrote:
> >>
> >> Wrap the io_ring_head_to_buf() macro value in an extra pair of parentheses
> >> so it is safe when composed into larger expressions, and to satisfy
> >> scripts/checkpatch.pl.
> >>
> >> Signed-off-by: Yi Xie <xieyi@kylinos.cn>
> >> ---
> >>  io_uring/kbuf.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
> >> index 63061aa1cab9..dd54e43e9ddf 100644
> >> --- a/io_uring/kbuf.c
> >> +++ b/io_uring/kbuf.c
> >> @@ -21,7 +21,7 @@
> >>  #define MAX_BIDS_PER_BGID (1 << 16)
> >>
> >>  /* Mapped buffer ring, return io_uring_buf from head */
> >> -#define io_ring_head_to_buf(br, head, mask)    &(br)->bufs[(head) & (mask)]
> >> +#define io_ring_head_to_buf(br, head, mask)    (&(br)->bufs[(head) & (mask)])
> >
> > Is there a reason this can't just be an inline function?
>
> No reason at all. But also don't see a strong reason why it can't just
> be a define. And generally I don't like cleanups like this, but this one
> at least made sense to me.

A macro can certainly work, but as this patch shows, it's tricky to
remember all the parentheses. An inline function also results in
better compiler error messages since the arguments are strongly typed.
And not applicable in this case, but if an argument is used multiple
times, a function ensures it's only evaluated once. I would generally
only reach for a macro when something can't be expressed as an inline
function.

Best,
Caleb

Re: [PATCH] io_uring: parenthesize io_ring_head_to_buf() expansion

[Jens Axboe]

On 5/14/26 8:43 AM, Caleb Sander Mateos wrote:
> On Thu, May 14, 2026 at 7:25 AM Jens Axboe <axboe@kernel.dk> wrote:
>>
>> On 5/14/26 8:22 AM, Caleb Sander Mateos wrote:
>>> On Thu, May 14, 2026 at 1:35?AM Yi Xie <xieyi@kylinos.cn> wrote:
>>>>
>>>> Wrap the io_ring_head_to_buf() macro value in an extra pair of parentheses
>>>> so it is safe when composed into larger expressions, and to satisfy
>>>> scripts/checkpatch.pl.
>>>>
>>>> Signed-off-by: Yi Xie <xieyi@kylinos.cn>
>>>> ---
>>>>  io_uring/kbuf.c | 2 +-
>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
>>>> index 63061aa1cab9..dd54e43e9ddf 100644
>>>> --- a/io_uring/kbuf.c
>>>> +++ b/io_uring/kbuf.c
>>>> @@ -21,7 +21,7 @@
>>>>  #define MAX_BIDS_PER_BGID (1 << 16)
>>>>
>>>>  /* Mapped buffer ring, return io_uring_buf from head */
>>>> -#define io_ring_head_to_buf(br, head, mask)    &(br)->bufs[(head) & (mask)]
>>>> +#define io_ring_head_to_buf(br, head, mask)    (&(br)->bufs[(head) & (mask)])
>>>
>>> Is there a reason this can't just be an inline function?
>>
>> No reason at all. But also don't see a strong reason why it can't just
>> be a define. And generally I don't like cleanups like this, but this one
>> at least made sense to me.
> 
> A macro can certainly work, but as this patch shows, it's tricky to
> remember all the parentheses. An inline function also results in
> better compiler error messages since the arguments are strongly typed.
> And not applicable in this case, but if an argument is used multiple
> times, a function ensures it's only evaluated once. I would generally
> only reach for a macro when something can't be expressed as an inline
> function.

I do know the benefits of a function over a macro :-)

I just don't think it'll buy us anything in this case.

-- 
Jens Axboe

Re: [PATCH] io_uring: parenthesize io_ring_head_to_buf() expansion

[Gabriel Krisman Bertazi]

Jens Axboe <axboe@kernel.dk> writes:

>>>  /* Mapped buffer ring, return io_uring_buf from head */
>>> -#define io_ring_head_to_buf(br, head, mask)    &(br)->bufs[(head) & (mask)]
>>> +#define io_ring_head_to_buf(br, head, mask)    (&(br)->bufs[(head) & (mask)])
>> 
>> Is there a reason this can't just be an inline function?
>
> And generally I don't like cleanups like this, but this one
> at least made sense to me.

The annoying part, IMO, is that we/I look at every trivial fix
wondering if it really is just a parenthesis fix, or if it's the next
CopyFail/Fragnesia fix with an obfuscated commit message..

ty

-- 
Gabriel Krisman Bertazi

Re: [PATCH] io_uring: parenthesize io_ring_head_to_buf() expansion

[Jens Axboe]

On 5/14/26 8:58 AM, Gabriel Krisman Bertazi wrote:
> Jens Axboe <axboe@kernel.dk> writes:
> 
>>>>  /* Mapped buffer ring, return io_uring_buf from head */
>>>> -#define io_ring_head_to_buf(br, head, mask)    &(br)->bufs[(head) & (mask)]
>>>> +#define io_ring_head_to_buf(br, head, mask)    (&(br)->bufs[(head) & (mask)])
>>>
>>> Is there a reason this can't just be an inline function?
>>
>> And generally I don't like cleanups like this, but this one
>> at least made sense to me.
> 
> The annoying part, IMO, is that we/I look at every trivial fix
> wondering if it really is just a parenthesis fix, or if it's the next
> CopyFail/Fragnesia fix with an obfuscated commit message..

No kidding, trust no one these days, it's mostly all LLM and suspect :/

-- 
Jens Axboe