* [PATCH] xen-netback: prefer xenbus_scanf() over xenbus_gather()
@ 2016-07-07 7:57 Jan Beulich
2016-07-07 9:55 ` [Xen-devel] " David Vrabel
2016-07-07 9:55 ` David Vrabel
0 siblings, 2 replies; 5+ messages in thread
From: Jan Beulich @ 2016-07-07 7:57 UTC (permalink / raw)
To: Wei Liu; +Cc: xen-devel, netdev
... for single items being collected: It is more typesafe (as the
compiler can check format string and to-be-written-to variable match)
and requires one less parameter to be passed.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
drivers/net/xen-netback/xenbus.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
--- 4.7-rc6-prefer-xenbus_scanf.orig/drivers/net/xen-netback/xenbus.c
+++ 4.7-rc6-prefer-xenbus_scanf/drivers/net/xen-netback/xenbus.c
@@ -842,16 +842,16 @@ static int connect_ctrl_ring(struct back
unsigned int evtchn;
int err;
- err = xenbus_gather(XBT_NIL, dev->otherend,
- "ctrl-ring-ref", "%u", &val, NULL);
- if (err)
+ err = xenbus_scanf(XBT_NIL, dev->otherend,
+ "ctrl-ring-ref", "%u", &val);
+ if (err <= 0)
goto done; /* The frontend does not have a control ring */
ring_ref = val;
- err = xenbus_gather(XBT_NIL, dev->otherend,
- "event-channel-ctrl", "%u", &val, NULL);
- if (err) {
+ err = xenbus_scanf(XBT_NIL, dev->otherend,
+ "event-channel-ctrl", "%u", &val);
+ if (err <= 0) {
xenbus_dev_fatal(dev, err,
"reading %s/event-channel-ctrl",
dev->otherend);
@@ -872,7 +872,7 @@ done:
return 0;
fail:
- return err;
+ return err ?: -ENODATA;
}
static void connect(struct backend_info *be)
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Xen-devel] [PATCH] xen-netback: prefer xenbus_scanf() over xenbus_gather()
2016-07-07 7:57 [PATCH] xen-netback: prefer xenbus_scanf() over xenbus_gather() Jan Beulich
@ 2016-07-07 9:55 ` David Vrabel
2016-07-07 10:06 ` Jan Beulich
2016-07-07 10:06 ` [Xen-devel] " Jan Beulich
2016-07-07 9:55 ` David Vrabel
1 sibling, 2 replies; 5+ messages in thread
From: David Vrabel @ 2016-07-07 9:55 UTC (permalink / raw)
To: Jan Beulich, Wei Liu; +Cc: xen-devel, netdev
On 07/07/16 08:57, Jan Beulich wrote:
> ... for single items being collected: It is more typesafe (as the
> compiler can check format string and to-be-written-to variable match)
> and requires one less parameter to be passed.
Do not split commit messages between the subject and the body in this
way. The body should be a complete description of the commit,
independent of the subject.
It's annoying to find only half a sentence in the body and have to go
re-read the subject again.
e.g.,
"xen-netback: prefer xenbus_scanf() over xenbus_gather()
xenbus_scanf() is preferred over xenbus_gather() because: a) the
compiler can check the types match the format; and b) one less parameter
is needed.
Use xenbus_scanf() instead of xenbus_gather() when reading only a single
key."
I think almost all of your commit messages suffer from this, please redo
them all.
> --- 4.7-rc6-prefer-xenbus_scanf.orig/drivers/net/xen-netback/xenbus.c
> +++ 4.7-rc6-prefer-xenbus_scanf/drivers/net/xen-netback/xenbus.c
> @@ -842,16 +842,16 @@ static int connect_ctrl_ring(struct back
> unsigned int evtchn;
> int err;
>
> - err = xenbus_gather(XBT_NIL, dev->otherend,
> - "ctrl-ring-ref", "%u", &val, NULL);
> - if (err)
> + err = xenbus_scanf(XBT_NIL, dev->otherend,
> + "ctrl-ring-ref", "%u", &val);
> + if (err <= 0)
< 0
David
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] xen-netback: prefer xenbus_scanf() over xenbus_gather()
2016-07-07 9:55 ` [Xen-devel] " David Vrabel
@ 2016-07-07 10:06 ` Jan Beulich
2016-07-07 10:06 ` [Xen-devel] " Jan Beulich
1 sibling, 0 replies; 5+ messages in thread
From: Jan Beulich @ 2016-07-07 10:06 UTC (permalink / raw)
To: David Vrabel; +Cc: xen-devel, Wei Liu, netdev
>>> On 07.07.16 at 11:55, <david.vrabel@citrix.com> wrote:
> On 07/07/16 08:57, Jan Beulich wrote:
>> --- 4.7-rc6-prefer-xenbus_scanf.orig/drivers/net/xen-netback/xenbus.c
>> +++ 4.7-rc6-prefer-xenbus_scanf/drivers/net/xen-netback/xenbus.c
>> @@ -842,16 +842,16 @@ static int connect_ctrl_ring(struct back
>> unsigned int evtchn;
>> int err;
>>
>> - err = xenbus_gather(XBT_NIL, dev->otherend,
>> - "ctrl-ring-ref", "%u", &val, NULL);
>> - if (err)
>> + err = xenbus_scanf(XBT_NIL, dev->otherend,
>> + "ctrl-ring-ref", "%u", &val);
>> + if (err <= 0)
>
> < 0
I disagree, as said elsewhere. If you feel like adjusting existing
instances is unnecessary, then drop those patches on the floor.
But I don't like to submit new uses with such a bogus check.
Jan
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Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Xen-devel] [PATCH] xen-netback: prefer xenbus_scanf() over xenbus_gather()
2016-07-07 9:55 ` [Xen-devel] " David Vrabel
2016-07-07 10:06 ` Jan Beulich
@ 2016-07-07 10:06 ` Jan Beulich
1 sibling, 0 replies; 5+ messages in thread
From: Jan Beulich @ 2016-07-07 10:06 UTC (permalink / raw)
To: David Vrabel; +Cc: Wei Liu, xen-devel, netdev
>>> On 07.07.16 at 11:55, <david.vrabel@citrix.com> wrote:
> On 07/07/16 08:57, Jan Beulich wrote:
>> --- 4.7-rc6-prefer-xenbus_scanf.orig/drivers/net/xen-netback/xenbus.c
>> +++ 4.7-rc6-prefer-xenbus_scanf/drivers/net/xen-netback/xenbus.c
>> @@ -842,16 +842,16 @@ static int connect_ctrl_ring(struct back
>> unsigned int evtchn;
>> int err;
>>
>> - err = xenbus_gather(XBT_NIL, dev->otherend,
>> - "ctrl-ring-ref", "%u", &val, NULL);
>> - if (err)
>> + err = xenbus_scanf(XBT_NIL, dev->otherend,
>> + "ctrl-ring-ref", "%u", &val);
>> + if (err <= 0)
>
> < 0
I disagree, as said elsewhere. If you feel like adjusting existing
instances is unnecessary, then drop those patches on the floor.
But I don't like to submit new uses with such a bogus check.
Jan
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] xen-netback: prefer xenbus_scanf() over xenbus_gather()
2016-07-07 7:57 [PATCH] xen-netback: prefer xenbus_scanf() over xenbus_gather() Jan Beulich
2016-07-07 9:55 ` [Xen-devel] " David Vrabel
@ 2016-07-07 9:55 ` David Vrabel
1 sibling, 0 replies; 5+ messages in thread
From: David Vrabel @ 2016-07-07 9:55 UTC (permalink / raw)
To: Jan Beulich, Wei Liu; +Cc: xen-devel, netdev
On 07/07/16 08:57, Jan Beulich wrote:
> ... for single items being collected: It is more typesafe (as the
> compiler can check format string and to-be-written-to variable match)
> and requires one less parameter to be passed.
Do not split commit messages between the subject and the body in this
way. The body should be a complete description of the commit,
independent of the subject.
It's annoying to find only half a sentence in the body and have to go
re-read the subject again.
e.g.,
"xen-netback: prefer xenbus_scanf() over xenbus_gather()
xenbus_scanf() is preferred over xenbus_gather() because: a) the
compiler can check the types match the format; and b) one less parameter
is needed.
Use xenbus_scanf() instead of xenbus_gather() when reading only a single
key."
I think almost all of your commit messages suffer from this, please redo
them all.
> --- 4.7-rc6-prefer-xenbus_scanf.orig/drivers/net/xen-netback/xenbus.c
> +++ 4.7-rc6-prefer-xenbus_scanf/drivers/net/xen-netback/xenbus.c
> @@ -842,16 +842,16 @@ static int connect_ctrl_ring(struct back
> unsigned int evtchn;
> int err;
>
> - err = xenbus_gather(XBT_NIL, dev->otherend,
> - "ctrl-ring-ref", "%u", &val, NULL);
> - if (err)
> + err = xenbus_scanf(XBT_NIL, dev->otherend,
> + "ctrl-ring-ref", "%u", &val);
> + if (err <= 0)
< 0
David
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2016-07-07 10:06 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2016-07-07 7:57 [PATCH] xen-netback: prefer xenbus_scanf() over xenbus_gather() Jan Beulich
2016-07-07 9:55 ` [Xen-devel] " David Vrabel
2016-07-07 10:06 ` Jan Beulich
2016-07-07 10:06 ` [Xen-devel] " Jan Beulich
2016-07-07 9:55 ` David Vrabel
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