4 files changed, 23 insertions, 13 deletions

diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index 1e8be12ebb55..6c0ead4be784 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -538,6 +538,8 @@ static int xenbus_file_open(struct inode *inode, struct file *filp)
 
 	nonseekable_open(inode, filp);
 
+	filp->f_mode &= ~FMODE_ATOMIC_POS; /* cdev-style semantics */
+
 	u = kzalloc(sizeof(*u), GFP_KERNEL);
 	if (u == NULL)
 		return -ENOMEM;
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 33a31cfef55d..4bdf654041e9 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -702,7 +702,7 @@ device_initcall(xenbus_probe_initcall);
  */
 static int __init xenstored_local_init(void)
 {
-	int err = 0;
+	int err = -ENOMEM;
 	unsigned long page = 0;
 	struct evtchn_alloc_unbound alloc_unbound;
 
@@ -826,7 +826,7 @@ static int __init xenbus_init(void)
 	 * Create xenfs mountpoint in /proc for compatibility with
 	 * utilities that expect to find "xenbus" under "/proc/xen".
 	 */
-	proc_mkdir("xen", NULL);
+	proc_create_mount_point("xen");
 #endif
 
 out_error:
diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c
index 04f7f85a5edf..37929df829a3 100644
--- a/drivers/xen/xenbus/xenbus_probe_backend.c
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -224,13 +224,7 @@ static int read_frontend_details(struct xenbus_device *xendev)
 
 int xenbus_dev_is_online(struct xenbus_device *dev)
 {
-	int rc, val;
-
-	rc = xenbus_scanf(XBT_NIL, dev->nodename, "online", "%d", &val);
-	if (rc != 1)
-		val = 0; /* no online node present */
-
-	return val;
+	return !!xenbus_read_unsigned(dev->nodename, "online", 0);
 }
 EXPORT_SYMBOL_GPL(xenbus_dev_is_online);
 
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 22f7cd711c57..6afb993c5809 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -559,6 +559,21 @@ int xenbus_scanf(struct xenbus_transaction t,
 }
 EXPORT_SYMBOL_GPL(xenbus_scanf);
 
+/* Read an (optional) unsigned value. */
+unsigned int xenbus_read_unsigned(const char *dir, const char *node,
+				  unsigned int default_val)
+{
+	unsigned int val;
+	int ret;
+
+	ret = xenbus_scanf(XBT_NIL, dir, node, "%u", &val);
+	if (ret <= 0)
+		val = default_val;
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(xenbus_read_unsigned);
+
 /* Single printf and write: returns -errno or 0. */
 int xenbus_printf(struct xenbus_transaction t,
 		  const char *dir, const char *node, const char *fmt, ...)
@@ -672,7 +687,7 @@ static bool xen_strict_xenbus_quirk(void)
 }
 static void xs_reset_watches(void)
 {
-	int err, supported = 0;
+	int err;
 
 	if (!xen_hvm_domain() || xen_initial_domain())
 		return;
@@ -680,9 +695,8 @@ static void xs_reset_watches(void)
 	if (xen_strict_xenbus_quirk())
 		return;
 
-	err = xenbus_scanf(XBT_NIL, "control",
-			"platform-feature-xs_reset_watches", "%d", &supported);
-	if (err != 1 || !supported)
+	if (!xenbus_read_unsigned("control",
+				  "platform-feature-xs_reset_watches", 0))
 		return;
 
 	err = xs_error(xs_single(XBT_NIL, XS_RESET_WATCHES, "", NULL));