[PATCH] xen: don't print error message in case of missing Xenstore entry

From: Juergen Gross
Date: Mon May 29 2017 - 05:14:08 EST


When registering for the Xenstore watch of the node control/sysrq the
handler will be called at once. Don't issue an error message if the
Xenstore node isn't there, as it will be created only when an event
is being triggered.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
drivers/xen/manage.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index c1ec8ee80924..7ddd0803da23 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -277,8 +277,11 @@ static void sysrq_handler(struct xenbus_watch *watch, const char *path,
err = xenbus_transaction_start(&xbt);
if (err)
return;
- if (xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key) < 0) {
- pr_err("Unable to read sysrq code in control/sysrq\n");
+ err = xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key);
+ if (err < 0) {
+ if (err != -ENOENT)
+ pr_err("Error %d reading sysrq code in control/sysrq\n",
+ err);
xenbus_transaction_end(xbt, 1);
return;
}
--
2.12.3