* [PATCH v2 4/4] xen-netback: prefer xenbus_scanf() over xenbus_gather()
[not found] <577FB70002000078000FC9FA@prv-mh.provo.novell.com>
@ 2016-07-08 12:28 ` Jan Beulich
2016-07-08 16:14 ` [Xen-devel] " Wei Liu
0 siblings, 1 reply; 2+ messages in thread
From: Jan Beulich @ 2016-07-08 12:28 UTC (permalink / raw)
To: Wei Liu; +Cc: david.vrabel, xen-devel, boris.ostrovsky, Juergen Gross, netdev
For single items being collected this should be preferred as being more
typesafe (as the compiler can check format string and to-be-written-to
variable match) and more efficient (requiring one less parameter to be
passed).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
v2: Avoid commit message to continue from subject.
---
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] 2+ messages in thread
* Re: [Xen-devel] [PATCH v2 4/4] xen-netback: prefer xenbus_scanf() over xenbus_gather()
2016-07-08 12:28 ` [PATCH v2 4/4] xen-netback: prefer xenbus_scanf() over xenbus_gather() Jan Beulich
@ 2016-07-08 16:14 ` Wei Liu
0 siblings, 0 replies; 2+ messages in thread
From: Wei Liu @ 2016-07-08 16:14 UTC (permalink / raw)
To: Jan Beulich
Cc: Wei Liu, Juergen Gross, xen-devel, boris.ostrovsky, david.vrabel,
netdev
On Fri, Jul 08, 2016 at 06:28:58AM -0600, Jan Beulich wrote:
> For single items being collected this should be preferred as being more
> typesafe (as the compiler can check format string and to-be-written-to
> variable match) and more efficient (requiring one less parameter to be
> passed).
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2016-07-08 16:14 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <577FB70002000078000FC9FA@prv-mh.provo.novell.com>
2016-07-08 12:28 ` [PATCH v2 4/4] xen-netback: prefer xenbus_scanf() over xenbus_gather() Jan Beulich
2016-07-08 16:14 ` [Xen-devel] " Wei Liu
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).