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Message-Id: <1444242652-17260-3-git-send-email-jiri@resnulli.us>
Date: Wed, 7 Oct 2015 20:30:51 +0200
From: Jiri Pirko <jiri@...nulli.us>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net, idosch@...lanox.com, eladr@...lanox.com,
sfeldma@...il.com, f.fainelli@...il.com, linux@...ck-us.net,
vivien.didelot@...oirfairelinux.com, andrew@...n.ch,
john.fastabend@...il.com, David.Laight@...LAB.COM
Subject: [patch net-next RFC 2/3] switchdev: allow caller to explicitly use deferred attr_set version
From: Jiri Pirko <jiri@...lanox.com>
Caller should know if he can call attr_set directly (when holding RTNL)
or if he has to use deferred version of this function.
This also allows drivers to sleep inside attr_set and report operation
status back to switchdev core. Switchdev core then warns if status is
not ok, instead of silent errors happening in drivers.
Signed-off-by: Jiri Pirko <jiri@...lanox.com>
---
include/net/switchdev.h | 2 +
net/bridge/br_stp.c | 4 +-
net/switchdev/switchdev.c | 113 +++++++++++++++++++++++++---------------------
3 files changed, 65 insertions(+), 54 deletions(-)
diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index 89266a3..320be44 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -168,6 +168,8 @@ int switchdev_port_attr_get(struct net_device *dev,
struct switchdev_attr *attr);
int switchdev_port_attr_set(struct net_device *dev,
struct switchdev_attr *attr);
+int switchdev_port_attr_set_deferred(struct net_device *dev,
+ struct switchdev_attr *attr);
int switchdev_port_obj_add(struct net_device *dev,
const struct switchdev_obj *obj);
int switchdev_port_obj_del(struct net_device *dev,
diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c
index 3a982c0..91a56b6 100644
--- a/net/bridge/br_stp.c
+++ b/net/bridge/br_stp.c
@@ -46,8 +46,8 @@ void br_set_state(struct net_bridge_port *p, unsigned int state)
int err;
p->state = state;
- err = switchdev_port_attr_set(p->dev, &attr);
- if (err && err != -EOPNOTSUPP)
+ err = switchdev_port_attr_set_deferred(p->dev, &attr);
+ if (err)
br_warn(p->br, "error setting offload STP state on port %u(%s)\n",
(unsigned int) p->port_no, p->dev->name);
}
diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
index 3fb05d5..c29f4ee 100644
--- a/net/switchdev/switchdev.c
+++ b/net/switchdev/switchdev.c
@@ -163,49 +163,6 @@ static int __switchdev_port_attr_set(struct net_device *dev,
return err;
}
-struct switchdev_attr_set_work {
- struct work_struct work;
- struct net_device *dev;
- struct switchdev_attr attr;
-};
-
-static void switchdev_port_attr_set_work(struct work_struct *work)
-{
- struct switchdev_attr_set_work *asw =
- container_of(work, struct switchdev_attr_set_work, work);
- int err;
-
- rtnl_lock();
- err = switchdev_port_attr_set(asw->dev, &asw->attr);
- if (err && err != -EOPNOTSUPP)
- netdev_err(asw->dev, "failed (err=%d) to set attribute (id=%d)\n",
- err, asw->attr.id);
- rtnl_unlock();
-
- dev_put(asw->dev);
- kfree(work);
-}
-
-static int switchdev_port_attr_set_defer(struct net_device *dev,
- struct switchdev_attr *attr)
-{
- struct switchdev_attr_set_work *asw;
-
- asw = kmalloc(sizeof(*asw), GFP_ATOMIC);
- if (!asw)
- return -ENOMEM;
-
- INIT_WORK(&asw->work, switchdev_port_attr_set_work);
-
- dev_hold(dev);
- asw->dev = dev;
- memcpy(&asw->attr, attr, sizeof(asw->attr));
-
- schedule_work(&asw->work);
-
- return 0;
-}
-
/**
* switchdev_port_attr_set - Set port attribute
*
@@ -215,21 +172,16 @@ static int switchdev_port_attr_set_defer(struct net_device *dev,
* Use a 2-phase prepare-commit transaction model to ensure
* system is not left in a partially updated state due to
* failure from driver/device.
+ *
+ * rtnl_lock must be held.
+ * must not be in atomic section.
*/
int switchdev_port_attr_set(struct net_device *dev, struct switchdev_attr *attr)
{
struct switchdev_trans trans;
int err;
- if (!rtnl_is_locked()) {
- /* Running prepare-commit transaction across stacked
- * devices requires nothing moves, so if rtnl_lock is
- * not held, schedule a worker thread to hold rtnl_lock
- * while setting attr.
- */
-
- return switchdev_port_attr_set_defer(dev, attr);
- }
+ ASSERT_RTNL();
switchdev_trans_init(&trans);
@@ -269,6 +221,63 @@ int switchdev_port_attr_set(struct net_device *dev, struct switchdev_attr *attr)
}
EXPORT_SYMBOL_GPL(switchdev_port_attr_set);
+struct switchdev_attr_set_work {
+ struct work_struct work;
+ struct net_device *dev;
+ struct switchdev_attr attr;
+};
+
+static void switchdev_port_attr_set_work(struct work_struct *work)
+{
+ struct switchdev_attr_set_work *asw =
+ container_of(work, struct switchdev_attr_set_work, work);
+ int err;
+
+ rtnl_lock();
+ err = switchdev_port_attr_set(asw->dev, &asw->attr);
+ if (err && err != -EOPNOTSUPP)
+ netdev_err(asw->dev, "failed (err=%d) to set attribute (id=%d)\n",
+ err, asw->attr.id);
+ rtnl_unlock();
+
+ dev_put(asw->dev);
+ kfree(asw);
+}
+
+/**
+ * switchdev_port_attr_set_deferred - Set port attribute - deferred
+ *
+ * @dev: port device
+ * @attr: attribute to set
+ *
+ * Use a 2-phase prepare-commit transaction model to ensure
+ * system is not left in a partially updated state due to
+ * failure from driver/device.
+ *
+ * This version can be safely called from context when RTNL
+ * mutex is not held and from atomic context.
+ */
+int switchdev_port_attr_set_deferred(struct net_device *dev,
+ struct switchdev_attr *attr)
+{
+ struct switchdev_attr_set_work *asw;
+
+ asw = kmalloc(sizeof(*asw), GFP_ATOMIC);
+ if (!asw)
+ return -ENOMEM;
+
+ INIT_WORK(&asw->work, switchdev_port_attr_set_work);
+
+ dev_hold(dev);
+ asw->dev = dev;
+ memcpy(&asw->attr, attr, sizeof(asw->attr));
+
+ schedule_work(&asw->work);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(switchdev_port_attr_set_deferred);
+
static int __switchdev_port_obj_add(struct net_device *dev,
const struct switchdev_obj *obj,
struct switchdev_trans *trans)
--
1.9.3
--
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