diff mbox

[v2] xen: don't print error message in case of missing Xenstore entry

Message ID 20170530185226.4666-1-jgross@suse.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jürgen Groß May 30, 2017, 6:52 p.m. UTC 
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@suse.com>
---
 drivers/xen/manage.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

Comments

Boris Ostrovsky May 30, 2017, 7:47 p.m. UTC | #1 
On 05/30/2017 02:52 PM, Juergen Gross wrote:
> 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@suse.com>

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
diff mbox

Patch

diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index c1ec8ee80924..60cf71f1b256 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -277,8 +277,16 @@  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) {
+		/*
+		 * The Xenstore watch fires directly after registering it and
+		 * after a suspend/resume cycle. So ENOENT is no error but
+		 * might happen in those cases.
+		 */
+		if (err != -ENOENT)
+			pr_err("Error %d reading sysrq code in control/sysrq\n",
+			       err);
 		xenbus_transaction_end(xbt, 1);
 		return;
 	}