#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/percpu.h>
+#include <linux/rcupdate.h>
#include <linux/rtnetlink.h>
#include <linux/compat.h>
#include <linux/version.h>
static const struct vport_ops **vport_ops_list;
static int n_vport_types;
+/* Protected by RCU read lock for reading, RTNL lock for writing. */
static struct hlist_head *dev_table;
#define VPORT_HASH_BUCKETS 1024
-/* Both RTNL lock and vport_mutex need to be held when updating dev_table.
- *
- * If you use vport_locate and then perform some operations, you need to hold
- * one of these locks if you don't want the vport to be deleted out from under
- * you.
- *
- * If you get a reference to a vport through a datapath, it is protected
- * by RCU and you need to hold rcu_read_lock instead when reading.
- *
- * If multiple locks are taken, the hierarchy is:
- * 1. RTNL
- * 2. DP
- * 3. vport
- */
-static DEFINE_MUTEX(vport_mutex);
-
-/**
- * vport_lock - acquire vport lock
- *
- * Acquire global vport lock. See above comment about locking requirements
- * and specific function definitions. May sleep.
- */
-void vport_lock(void)
-{
- mutex_lock(&vport_mutex);
-}
-
-/**
- * vport_unlock - release vport lock
- *
- * Release lock acquired with vport_lock.
- */
-void vport_unlock(void)
-{
- mutex_unlock(&vport_mutex);
-}
-
-#define ASSERT_VPORT() \
-do { \
- if (unlikely(!mutex_is_locked(&vport_mutex))) { \
- pr_err("vport lock not held at %s (%d)\n", \
- __FILE__, __LINE__); \
- dump_stack(); \
- } \
-} while (0)
-
/**
* vport_init - initialize vport subsystem
*
*
* @name: name of port to find
*
- * Either RTNL or vport lock must be acquired before calling this function
- * and held while using the found port. See the locking comments at the
- * top of the file.
+ * Must be called with RTNL or RCU read lock.
*/
struct vport *vport_locate(const char *name)
{
struct vport *vport;
struct hlist_node *node;
- if (unlikely(!mutex_is_locked(&vport_mutex) && !rtnl_is_locked())) {
- pr_err("neither RTNL nor vport lock held in vport_locate\n");
- dump_stack();
- }
-
- rcu_read_lock();
-
- hlist_for_each_entry(vport, node, bucket, hash_node)
+ hlist_for_each_entry_rcu(vport, node, bucket, hash_node)
if (!strcmp(name, vport_get_name(vport)))
- goto out;
-
- vport = NULL;
-
-out:
- rcu_read_unlock();
- return vport;
-}
+ return vport;
-static void register_vport(struct vport *vport)
-{
- hlist_add_head(&vport->hash_node, hash_bucket(vport_get_name(vport)));
-}
-
-static void unregister_vport(struct vport *vport)
-{
- hlist_del(&vport->hash_node);
+ return NULL;
}
static void release_vport(struct kobject *kobj)
* @vport: vport to free
*
* Frees a vport allocated with vport_alloc() when it is no longer needed.
+ *
+ * The caller must ensure that an RCU grace period has passed since the last
+ * time @vport was in a datapath.
*/
void vport_free(struct vport *vport)
{
* @parms: Information about new vport.
*
* Creates a new vport with the specified configuration (which is dependent on
- * device type) and attaches it to a datapath. Both RTNL and vport locks must
- * be held.
+ * device type) and attaches it to a datapath. RTNL lock must be held.
*/
struct vport *vport_add(const struct vport_parms *parms)
{
int i;
ASSERT_RTNL();
- ASSERT_VPORT();
for (i = 0; i < n_vport_types; i++) {
if (vport_ops_list[i]->type == parms->type) {
goto out;
}
- register_vport(vport);
+ hlist_add_head_rcu(&vport->hash_node,
+ hash_bucket(vport_get_name(vport)));
return vport;
}
}
}
/**
- * vport_del - delete existing vport device (for kernel callers)
+ * vport_del - delete existing vport device
*
* @vport: vport to delete.
*
* Detaches @vport from its datapath and destroys it. It is possible to fail
- * for reasons such as lack of memory. Both RTNL and vport locks must be held.
+ * for reasons such as lack of memory. RTNL lock must be held.
*/
int vport_del(struct vport *vport)
{
ASSERT_RTNL();
- ASSERT_VPORT();
- unregister_vport(vport);
+ hlist_del_rcu(&vport->hash_node);
return vport->ops->destroy(vport);
}
}
/**
- * vport_set_stats - sets offset device stats (for kernel callers)
+ * vport_set_stats - sets offset device stats
*
* @vport: vport on which to set stats
* @stats: stats to set
* Provides a set of transmit, receive, and error stats to be added as an
* offset to the collect data when stats are retreived. Some devices may not
* support setting the stats, in which case the result will always be
- * -EOPNOTSUPP. RTNL lock must be held.
+ * -EOPNOTSUPP.
+ *
+ * Must be called with RTNL lock.
*/
int vport_set_stats(struct vport *vport, struct rtnl_link_stats64 *stats)
{
*
* @vport: vport from which to retrieve the type.
*
- * Retrieves the type of the given device. Either RTNL lock or rcu_read_lock
- * must be held.
+ * Retrieves the type of the given device.
*/
enum odp_vport_type vport_get_type(const struct vport *vport)
{
}
/**
- * vport_get_stats - retrieve device stats (for kernel callers)
+ * vport_get_stats - retrieve device stats
*
* @vport: vport from which to retrieve the stats
* @stats: location to store stats
*
* Retrieves transmit, receive, and error stats for the given device.
+ *
+ * Must be called with RTNL lock or rcu_read_lock.
*/
int vport_get_stats(struct vport *vport, struct rtnl_link_stats64 *stats)
{
*
* @vport: vport from which to retrieve the flags
*
- * Retrieves the flags of the given device. Either RTNL lock or rcu_read_lock
- * must be held.
+ * Retrieves the flags of the given device.
+ *
+ * Must be called with RTNL lock or rcu_read_lock.
*/
unsigned vport_get_flags(const struct vport *vport)
{
*
* @vport: vport on which to check status.
*
- * Checks whether the given device is running. Either RTNL lock or
- * rcu_read_lock must be held.
+ * Checks whether the given device is running.
+ *
+ * Must be called with RTNL lock or rcu_read_lock.
*/
int vport_is_running(const struct vport *vport)
{
*
* @vport: vport from which to check status
*
- * Retrieves the RFC2863 operstate of the given device. Either RTNL lock or
- * rcu_read_lock must be held.
+ * Retrieves the RFC2863 operstate of the given device.
+ *
+ * Must be called with RTNL lock or rcu_read_lock.
*/
unsigned char vport_get_operstate(const struct vport *vport)
{
*
* Retrieves the system interface index of the given device or 0 if
* the device does not have one (in the case of virtual ports).
- * Returns a negative index on error. Either RTNL lock or
- * rcu_read_lock must be held.
+ * Returns a negative index on error.
+ *
+ * Must be called with RTNL lock or rcu_read_lock.
*/
int vport_get_ifindex(const struct vport *vport)
{
* Retrieves the system link index of the given device. The link is the index
* of the interface on which the packet will actually be sent. In most cases
* this is the same as the ifindex but may be different for tunnel devices.
- * Returns a negative index on error. Either RTNL lock or rcu_read_lock must
- * be held.
+ * Returns a negative index on error.
+ *
+ * Must be called with RTNL lock or rcu_read_lock.
*/
int vport_get_iflink(const struct vport *vport)
{
}
/**
- * vport_get_mtu - retrieve device MTU (for kernel callers)
+ * vport_get_mtu - retrieve device MTU
*
* @vport: vport from which to retrieve MTU
*
- * Retrieves the MTU of the given device. Either RTNL lock or rcu_read_lock
- * must be held.
+ * Retrieves the MTU of the given device. Returns 0 if @vport does not have an
+ * MTU (as e.g. some tunnels do not). Either RTNL lock or rcu_read_lock must
+ * be held.
*/
int vport_get_mtu(const struct vport *vport)
{
+ if (!vport->ops->get_mtu)
+ return 0;
return vport->ops->get_mtu(vport);
}
*
* Retrieves the configuration of the given device, appending an
* %ODP_VPORT_ATTR_OPTIONS attribute that in turn contains nested
- * vport-specific attributes to @skb. Either RTNL lock or rcu_read_lock must
- * be held.
+ * vport-specific attributes to @skb.
*
* Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
- * negative error code if a real error occurred.
+ * negative error code if a real error occurred. If an error occurs, @skb is
+ * left unmodified.
+ *
+ * Must be called with RTNL lock or rcu_read_lock.
*/
int vport_get_options(const struct vport *vport, struct sk_buff *skb)
{
if (vport->ops->get_options) {
int err = vport->ops->get_options(vport, skb);
- if (err)
+ if (err) {
+ nla_nest_cancel(skb, nla);
return err;
+ }
}
nla_nest_end(skb, nla);
int sent;
mtu = vport_get_mtu(vport);
- if (unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
+ if (mtu && unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
if (net_ratelimit())
pr_warn("%s: dropped over-mtu packet: %d > %d\n",
dp_name(vport->dp), packet_length(skb), mtu);
git://git.onelab.eu / sliver-openvswitch.git / blobdiff