[ovs-dev] [netlink v5 52/61] datapath: Adopt Generic Netlink-compatible locking.
Ben Pfaff
blp at nicira.com
Thu Jan 27 00:23:35 UTC 2011
The kernel Generic Netlink layer always holds a mutex (genl_lock) when it
invokes callbacks, so that means that there is no point in having
per-datapath mutexes or a separate vport lock. This commit removes them.
This commit breaks support for Linux before 2.6.35 because it calls
genl_lock(), which wasn't exported before that version. That problem will
be fixed once the whole userspace interface transitions to Generic
Netlink a few commits from now.
Signed-off-by: Ben Pfaff <blp at nicira.com>
---
datapath/datapath.c | 481 +++++++++-----------
datapath/datapath.h | 14 +-
datapath/dp_notify.c | 9 +-
datapath/linux-2.6/Modules.mk | 1 +
.../linux-2.6/compat-2.6/include/linux/genetlink.h | 15 +
datapath/table.c | 22 +-
datapath/vport.c | 52 ++-
7 files changed, 291 insertions(+), 303 deletions(-)
create mode 100644 datapath/linux-2.6/compat-2.6/include/linux/genetlink.h
diff --git a/datapath/datapath.c b/datapath/datapath.c
index 599a20b..9285b7d 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -20,6 +20,7 @@
#include <linux/delay.h>
#include <linux/time.h>
#include <linux/etherdevice.h>
+#include <linux/genetlink.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
@@ -56,52 +57,50 @@
int (*dp_ioctl_hook)(struct net_device *dev, struct ifreq *rq, int cmd);
EXPORT_SYMBOL(dp_ioctl_hook);
-/* Datapaths. Protected on the read side by rcu_read_lock, on the write side
- * by dp_mutex.
+/**
+ * DOC: Locking:
*
- * dp_mutex nests inside the RTNL lock: if you need both you must take the RTNL
- * lock first.
+ * Writes to device state (add/remove datapath, port, set operations on vports,
+ * etc.) are protected by RTNL.
*
- * It is safe to access the datapath and vport structures with just
- * dp_mutex.
+ * Writes to other state (flow table modifications, set miscellaneous datapath
+ * parameters such as drop frags, etc.) are protected by genl_mutex. The RTNL
+ * lock nests inside genl_mutex.
+ *
+ * Reads are protected by RCU.
+ *
+ * There are a few special cases (mostly stats) that have their own
+ * synchronization but they nest under all of above and don't interact with
+ * each other.
*/
+
+/* Protected by genl_mutex. */
static struct datapath __rcu *dps[256];
-static DEFINE_MUTEX(dp_mutex);
static struct vport *new_vport(const struct vport_parms *);
-/* Must be called with rcu_read_lock or dp_mutex. */
+/* Must be called with rcu_read_lock, genl_mutex, or RTNL lock. */
struct datapath *get_dp(int dp_idx)
{
if (dp_idx < 0 || dp_idx >= ARRAY_SIZE(dps))
return NULL;
+
return rcu_dereference_check(dps[dp_idx], rcu_read_lock_held() ||
- lockdep_is_held(&dp_mutex));
+ lockdep_rtnl_is_held() ||
+ lockdep_genl_is_held());
}
EXPORT_SYMBOL_GPL(get_dp);
-static struct datapath *get_dp_locked(int dp_idx)
-{
- struct datapath *dp;
-
- mutex_lock(&dp_mutex);
- dp = get_dp(dp_idx);
- if (dp)
- mutex_lock(&dp->mutex);
- mutex_unlock(&dp_mutex);
- return dp;
-}
-
+/* Must be called with genl_mutex. */
static struct tbl *get_table_protected(struct datapath *dp)
{
- return rcu_dereference_protected(dp->table,
- lockdep_is_held(&dp->mutex));
+ return rcu_dereference_protected(dp->table, lockdep_genl_is_held());
}
+/* Must be called with rcu_read_lock or RTNL lock. */
static struct vport *get_vport_protected(struct datapath *dp, u16 port_no)
{
- return rcu_dereference_protected(dp->ports[port_no],
- lockdep_is_held(&dp->mutex));
+ return rcu_dereference_rtnl(dp->ports[port_no]);
}
/* Must be called with rcu_read_lock or RTNL lock. */
@@ -121,6 +120,7 @@ static inline size_t br_nlmsg_size(void)
+ nla_total_size(1); /* IFLA_OPERSTATE */
}
+/* Caller must hold RTNL lock. */
static int dp_fill_ifinfo(struct sk_buff *skb,
const struct vport *port,
int event, unsigned int flags)
@@ -172,6 +172,7 @@ nla_put_failure:
return -EMSGSIZE;
}
+/* Caller must hold RTNL lock. */
static void dp_ifinfo_notify(int event, struct vport *port)
{
struct sk_buff *skb;
@@ -218,25 +219,7 @@ static void destroy_dp_rcu(struct rcu_head *rcu)
kobject_put(&dp->ifobj);
}
-/* Caller must hold RTNL, dp_mutex, and dp->mutex. */
-static void destroy_dp(struct datapath *dp)
-{
- struct vport *p, *n;
-
- list_for_each_entry_safe (p, n, &dp->port_list, node)
- if (p->port_no != ODPP_LOCAL)
- dp_detach_port(p);
-
- dp_sysfs_del_dp(dp);
- rcu_assign_pointer(dps[dp->dp_idx], NULL);
- dp_detach_port(get_vport_protected(dp, ODPP_LOCAL));
-
- mutex_unlock(&dp->mutex);
- call_rcu(&dp->rcu, destroy_dp_rcu);
- module_put(THIS_MODULE);
-}
-
-/* Called with RTNL lock and dp->mutex. */
+/* Called with RTNL lock and genl_lock. */
static struct vport *new_vport(const struct vport_parms *parms)
{
struct vport *vport;
@@ -246,7 +229,7 @@ static struct vport *new_vport(const struct vport_parms *parms)
struct datapath *dp = parms->dp;
rcu_assign_pointer(dp->ports[parms->port_no], vport);
- list_add_rcu(&vport->node, &dp->port_list);
+ list_add(&vport->node, &dp->port_list);
dp_ifinfo_notify(RTM_NEWLINK, vport);
}
@@ -254,6 +237,7 @@ static struct vport *new_vport(const struct vport_parms *parms)
return vport;
}
+/* Called with RTNL lock. */
int dp_detach_port(struct vport *p)
{
ASSERT_RTNL();
@@ -263,7 +247,7 @@ int dp_detach_port(struct vport *p)
dp_ifinfo_notify(RTM_DELLINK, p);
/* First drop references to device. */
- list_del_rcu(&p->node);
+ list_del(&p->node);
rcu_assign_pointer(p->dp->ports[p->port_no], NULL);
/* Then destroy it. */
@@ -512,34 +496,27 @@ err:
return err;
}
+/* Called with genl_mutex. */
static int flush_flows(int dp_idx)
{
struct tbl *old_table;
struct tbl *new_table;
struct datapath *dp;
- int err;
- dp = get_dp_locked(dp_idx);
- err = -ENODEV;
+ dp = get_dp(dp_idx);
if (!dp)
- goto exit;
+ return -ENODEV;
old_table = get_table_protected(dp);
new_table = tbl_create(TBL_MIN_BUCKETS);
- err = -ENOMEM;
if (!new_table)
- goto exit_unlock;
+ return -ENOMEM;
rcu_assign_pointer(dp->table, new_table);
tbl_deferred_destroy(old_table, flow_free_tbl);
- err = 0;
-
-exit_unlock:
- mutex_unlock(&dp->mutex);
-exit:
- return err;
+ return 0;
}
static int validate_actions(const struct nlattr *actions, u32 actions_len)
@@ -644,6 +621,7 @@ static void clear_stats(struct sw_flow *flow)
flow->byte_count = 0;
}
+/* Called with genl_mutex. */
static int expand_table(struct datapath *dp)
{
struct tbl *old_table = get_table_protected(dp);
@@ -771,7 +749,9 @@ static void get_dp_stats(struct datapath *dp, struct odp_stats *stats)
}
}
-/* MTU of the dp pseudo-device: ETH_DATA_LEN or the minimum of the ports */
+/* MTU of the dp pseudo-device: ETH_DATA_LEN or the minimum of the ports.
+ * Called with RTNL lock.
+ */
int dp_min_mtu(const struct datapath *dp)
{
struct vport *p;
@@ -779,7 +759,7 @@ int dp_min_mtu(const struct datapath *dp)
ASSERT_RTNL();
- list_for_each_entry_rcu (p, &dp->port_list, node) {
+ list_for_each_entry (p, &dp->port_list, node) {
int dev_mtu;
/* Skip any internal ports, since that's what we're trying to
@@ -795,8 +775,9 @@ int dp_min_mtu(const struct datapath *dp)
return mtu ? mtu : ETH_DATA_LEN;
}
-/* Sets the MTU of all datapath devices to the minimum of the ports. Must
- * be called with RTNL lock. */
+/* Sets the MTU of all datapath devices to the minimum of the ports
+ * Called with RTNL lock.
+ */
void set_internal_devs_mtu(const struct datapath *dp)
{
struct vport *p;
@@ -806,7 +787,7 @@ void set_internal_devs_mtu(const struct datapath *dp)
mtu = dp_min_mtu(dp);
- list_for_each_entry_rcu (p, &dp->port_list, node) {
+ list_for_each_entry (p, &dp->port_list, node) {
if (is_internal_vport(p))
vport_set_mtu(p, mtu);
}
@@ -829,6 +810,7 @@ static const struct nla_policy flow_policy[ODP_FLOW_ATTR_MAX + 1] = {
[ODP_FLOW_ATTR_STATE] = { .type = NLA_U64 },
};
+
static int copy_flow_to_user(struct odp_flow __user *dst, struct datapath *dp,
struct sw_flow *flow, u32 total_len, u64 state)
{
@@ -842,14 +824,13 @@ static int copy_flow_to_user(struct odp_flow __user *dst, struct datapath *dp,
int err;
sf_acts = rcu_dereference_protected(flow->sf_acts,
- lockdep_is_held(&dp->mutex));
+ lockdep_genl_is_held());
skb = alloc_skb(128 + FLOW_BUFSIZE + sf_acts->actions_len, GFP_KERNEL);
err = -ENOMEM;
if (!skb)
goto exit;
- rcu_read_lock();
odp_flow = (struct odp_flow*)__skb_put(skb, sizeof(struct odp_flow));
odp_flow->dp_idx = dp->dp_idx;
odp_flow->total_len = total_len;
@@ -859,7 +840,7 @@ static int copy_flow_to_user(struct odp_flow __user *dst, struct datapath *dp,
goto nla_put_failure;
err = flow_to_nlattrs(&flow->key, skb);
if (err)
- goto exit_unlock;
+ goto exit_free;
nla_nest_end(skb, nla);
nla = nla_nest_start(skb, ODP_FLOW_ATTR_ACTIONS);
@@ -892,17 +873,17 @@ static int copy_flow_to_user(struct odp_flow __user *dst, struct datapath *dp,
odp_flow->len = skb->len;
err = copy_to_user(dst, skb->data, skb->len) ? -EFAULT : 0;
- goto exit_unlock;
+ goto exit_free;
nla_put_failure:
err = -EMSGSIZE;
-exit_unlock:
- rcu_read_unlock();
+exit_free:
kfree_skb(skb);
exit:
return err;
}
+/* Called with genl_mutex. */
static struct sk_buff *copy_flow_from_user(struct odp_flow __user *uodp_flow,
struct dp_flowcmd *flowcmd)
{
@@ -987,10 +968,10 @@ static int new_flow(unsigned int cmd, struct odp_flow __user *uodp_flow)
if (IS_ERR(skb))
goto exit;
- dp = get_dp_locked(flowcmd.dp_idx);
+ dp = get_dp(flowcmd.dp_idx);
error = -ENODEV;
if (!dp)
- goto error_kfree_skb;
+ goto exit;
hash = flow_hash(&flowcmd.key);
table = get_table_protected(dp);
@@ -1001,13 +982,13 @@ static int new_flow(unsigned int cmd, struct odp_flow __user *uodp_flow)
/* Bail out if we're not allowed to create a new flow. */
error = -ENOENT;
if (cmd == ODP_FLOW_SET)
- goto error_unlock_dp;
+ goto exit;
/* Expand table, if necessary, to make room. */
if (tbl_count(table) >= tbl_n_buckets(table)) {
error = expand_table(dp);
if (error)
- goto error_unlock_dp;
+ goto exit;
table = get_table_protected(dp);
}
@@ -1015,7 +996,7 @@ static int new_flow(unsigned int cmd, struct odp_flow __user *uodp_flow)
flow = flow_alloc();
if (IS_ERR(flow)) {
error = PTR_ERR(flow);
- goto error_unlock_dp;
+ goto exit;
}
flow->key = flowcmd.key;
clear_stats(flow);
@@ -1052,7 +1033,7 @@ static int new_flow(unsigned int cmd, struct odp_flow __user *uodp_flow)
/* Update actions. */
flow = flow_cast(flow_node);
old_acts = rcu_dereference_protected(flow->sf_acts,
- lockdep_is_held(&dp->mutex));
+ lockdep_genl_is_held());
if (flowcmd.actions &&
(old_acts->actions_len != flowcmd.actions_len ||
memcmp(old_acts->actions, flowcmd.actions,
@@ -1080,13 +1061,10 @@ static int new_flow(unsigned int cmd, struct odp_flow __user *uodp_flow)
}
}
kfree_skb(skb);
- mutex_unlock(&dp->mutex);
return 0;
error_free_flow:
flow_put(flow);
-error_unlock_dp:
- mutex_unlock(&dp->mutex);
error_kfree_skb:
kfree_skb(skb);
exit:
@@ -1104,25 +1082,22 @@ static int get_or_del_flow(unsigned int cmd, struct odp_flow __user *uodp_flow)
int err;
skb = copy_flow_from_user(uodp_flow, &flowcmd);
- err = PTR_ERR(skb);
if (IS_ERR(skb))
- goto exit;
+ return PTR_ERR(skb);
- dp = get_dp_locked(flowcmd.dp_idx);
- err = -ENODEV;
+ dp = get_dp(flowcmd.dp_idx);
if (!dp)
- goto exit_kfree_skb;
+ return -ENODEV;
table = get_table_protected(dp);
flow_node = tbl_lookup(table, &flowcmd.key, flow_hash(&flowcmd.key), flow_cmp);
- err = -ENOENT;
if (!flow_node)
- goto exit_unlock_dp;
+ return -ENOENT;
if (cmd == ODP_FLOW_DEL) {
err = tbl_remove(table, flow_node);
if (err)
- goto exit_unlock_dp;
+ return err;
}
flow = flow_cast(flow_node);
@@ -1130,11 +1105,6 @@ static int get_or_del_flow(unsigned int cmd, struct odp_flow __user *uodp_flow)
if (!err && cmd == ODP_FLOW_DEL)
flow_deferred_free(flow);
-exit_unlock_dp:
- mutex_unlock(&dp->mutex);
-exit_kfree_skb:
- kfree_skb(skb);
-exit:
return err;
}
@@ -1153,25 +1123,23 @@ static int dump_flow(struct odp_flow __user *uodp_flow)
if (IS_ERR(skb))
goto exit;
- dp = get_dp_locked(flowcmd.dp_idx);
+ dp = get_dp(flowcmd.dp_idx);
err = -ENODEV;
if (!dp)
- goto exit_free;
+ goto exit_kfree_skb;
bucket = flowcmd.state >> 32;
obj = flowcmd.state;
- flow_node = tbl_next(dp->table, &bucket, &obj);
+ flow_node = tbl_next(get_table_protected(dp), &bucket, &obj);
err = -ENODEV;
if (!flow_node)
- goto exit_unlock_dp;
+ goto exit_kfree_skb;
flow = flow_cast(flow_node);
err = copy_flow_to_user(uodp_flow, dp, flow, flowcmd.total_len,
((u64)bucket << 32) | obj);
-exit_unlock_dp:
- mutex_unlock(&dp->mutex);
-exit_free:
+exit_kfree_skb:
kfree_skb(skb);
exit:
return err;
@@ -1183,6 +1151,7 @@ static const struct nla_policy datapath_policy[ODP_DP_ATTR_MAX + 1] = {
[ODP_DP_ATTR_SAMPLING] = { .type = NLA_U32 },
};
+/* Called with genl_mutex. */
static int copy_datapath_to_user(void __user *dst, struct datapath *dp, uint32_t total_len)
{
struct odp_datapath *odp_datapath;
@@ -1231,6 +1200,7 @@ exit:
return err;
}
+/* Called with genl_mutex. */
static struct sk_buff *copy_datapath_from_user(struct odp_datapath __user *uodp_datapath, struct nlattr *a[ODP_DP_ATTR_MAX + 1])
{
struct odp_datapath *odp_datapath;
@@ -1281,23 +1251,15 @@ error_free_skb:
return ERR_PTR(err);
}
-/* Called with dp_mutex and optionally with RTNL lock also.
- * Holds the returned datapath's mutex on return.
- */
+/* Called with genl_mutex and optionally with RTNL lock also. */
static struct datapath *lookup_datapath(struct odp_datapath *odp_datapath, struct nlattr *a[ODP_DP_ATTR_MAX + 1])
{
- WARN_ON_ONCE(!mutex_is_locked(&dp_mutex));
-
if (!a[ODP_DP_ATTR_NAME]) {
- struct datapath *dp;
-
- dp = get_dp(odp_datapath->dp_idx);
+ struct datapath *dp = get_dp(odp_datapath->dp_idx);
if (!dp)
return ERR_PTR(-ENODEV);
- mutex_lock(&dp->mutex);
return dp;
} else {
- struct datapath *dp;
struct vport *vport;
int dp_idx;
@@ -1308,13 +1270,11 @@ static struct datapath *lookup_datapath(struct odp_datapath *odp_datapath, struc
if (dp_idx < 0)
return ERR_PTR(-ENODEV);
-
- dp = get_dp(dp_idx);
- mutex_lock(&dp->mutex);
- return dp;
+ return vport->dp;
}
}
+/* Called with genl_mutex. */
static void change_datapath(struct datapath *dp, struct nlattr *a[ODP_DP_ATTR_MAX + 1])
{
if (a[ODP_DP_ATTR_IPV4_FRAGS])
@@ -1346,10 +1306,9 @@ static int new_datapath(struct odp_datapath __user *uodp_datapath)
goto err_free_skb;
rtnl_lock();
- mutex_lock(&dp_mutex);
err = -ENODEV;
if (!try_module_get(THIS_MODULE))
- goto err_unlock_dp_mutex;
+ goto err_unlock_rtnl;
dp_idx = odp_datapath->dp_idx;
if (dp_idx < 0) {
@@ -1372,8 +1331,6 @@ static int new_datapath(struct odp_datapath __user *uodp_datapath)
if (dp == NULL)
goto err_put_module;
INIT_LIST_HEAD(&dp->port_list);
- mutex_init(&dp->mutex);
- mutex_lock(&dp->mutex);
dp->dp_idx = dp_idx;
for (i = 0; i < DP_N_QUEUES; i++)
skb_queue_head_init(&dp->queues[i]);
@@ -1417,8 +1374,6 @@ static int new_datapath(struct odp_datapath __user *uodp_datapath)
rcu_assign_pointer(dps[dp_idx], dp);
dp_sysfs_add_dp(dp);
- mutex_unlock(&dp->mutex);
- mutex_unlock(&dp_mutex);
rtnl_unlock();
return 0;
@@ -1428,12 +1383,10 @@ err_destroy_local_port:
err_destroy_table:
tbl_destroy(get_table_protected(dp), NULL);
err_free_dp:
- mutex_unlock(&dp->mutex);
kfree(dp);
err_put_module:
module_put(THIS_MODULE);
-err_unlock_dp_mutex:
- mutex_unlock(&dp_mutex);
+err_unlock_rtnl:
rtnl_unlock();
err_free_skb:
kfree_skb(skb);
@@ -1444,6 +1397,7 @@ err:
static int del_datapath(struct odp_datapath __user *uodp_datapath)
{
struct nlattr *a[ODP_DP_ATTR_MAX + 1];
+ struct vport *vport, *next_vport;
struct datapath *dp;
struct sk_buff *skb;
int err;
@@ -1454,18 +1408,26 @@ static int del_datapath(struct odp_datapath __user *uodp_datapath)
goto exit;
rtnl_lock();
- mutex_lock(&dp_mutex);
dp = lookup_datapath((struct odp_datapath *)skb->data, a);
err = PTR_ERR(dp);
if (IS_ERR(dp))
goto exit_free;
- destroy_dp(dp);
+ list_for_each_entry_safe (vport, next_vport, &dp->port_list, node)
+ if (vport->port_no != ODPP_LOCAL)
+ dp_detach_port(vport);
+
+ dp_sysfs_del_dp(dp);
+ rcu_assign_pointer(dps[dp->dp_idx], NULL);
+ dp_detach_port(get_vport_protected(dp, ODPP_LOCAL));
+
+ call_rcu(&dp->rcu, destroy_dp_rcu);
+ module_put(THIS_MODULE);
+
err = 0;
exit_free:
kfree_skb(skb);
- mutex_unlock(&dp_mutex);
rtnl_unlock();
exit:
return err;
@@ -1483,19 +1445,16 @@ static int set_datapath(struct odp_datapath __user *uodp_datapath)
if (IS_ERR(skb))
goto exit;
- mutex_lock(&dp_mutex);
dp = lookup_datapath((struct odp_datapath *)skb->data, a);
err = PTR_ERR(dp);
if (IS_ERR(dp))
goto exit_free;
change_datapath(dp, a);
- mutex_unlock(&dp->mutex);
err = 0;
exit_free:
kfree_skb(skb);
- mutex_unlock(&dp_mutex);
exit:
return err;
}
@@ -1514,16 +1473,13 @@ static int get_datapath(struct odp_datapath __user *uodp_datapath)
goto exit;
odp_datapath = (struct odp_datapath *)skb->data;
- mutex_lock(&dp_mutex);
dp = lookup_datapath(odp_datapath, a);
- mutex_unlock(&dp_mutex);
err = PTR_ERR(dp);
if (IS_ERR(dp))
goto exit_free;
err = copy_datapath_to_user(uodp_datapath, dp, odp_datapath->total_len);
- mutex_unlock(&dp->mutex);
exit_free:
kfree_skb(skb);
exit:
@@ -1544,22 +1500,15 @@ static int dump_datapath(struct odp_datapath __user *uodp_datapath)
goto exit;
odp_datapath = (struct odp_datapath *)skb->data;
- mutex_lock(&dp_mutex);
+ err = -ENODEV;
for (dp_idx = odp_datapath->dp_idx; dp_idx < ARRAY_SIZE(dps); dp_idx++) {
struct datapath *dp = get_dp(dp_idx);
if (!dp)
continue;
- mutex_lock(&dp->mutex);
- mutex_unlock(&dp_mutex);
err = copy_datapath_to_user(uodp_datapath, dp, odp_datapath->total_len);
- mutex_unlock(&dp->mutex);
- goto exit_free;
+ break;
}
- mutex_unlock(&dp_mutex);
- err = -ENODEV;
-
-exit_free:
kfree_skb(skb);
exit:
return err;
@@ -1575,7 +1524,8 @@ static const struct nla_policy vport_policy[ODP_VPORT_ATTR_MAX + 1] = {
[ODP_VPORT_ATTR_OPTIONS] = { .type = NLA_NESTED },
};
-static int copy_vport_to_user(void __user *dst, struct vport *vport, uint32_t total_len)
+/* Called with RCU read lock. */
+static struct sk_buff *odp_vport_build_info(struct vport *vport, uint32_t total_len)
{
struct odp_vport *odp_vport;
struct sk_buff *skb;
@@ -1583,12 +1533,11 @@ static int copy_vport_to_user(void __user *dst, struct vport *vport, uint32_t to
int ifindex, iflink;
int err;
- skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+ skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
err = -ENOMEM;
if (!skb)
- goto exit;
+ goto err;
- rcu_read_lock();
odp_vport = (struct odp_vport*)__skb_put(skb, sizeof(struct odp_vport));
odp_vport->dp_idx = vport->dp->dp_idx;
odp_vport->total_len = total_len;
@@ -1619,19 +1568,17 @@ static int copy_vport_to_user(void __user *dst, struct vport *vport, uint32_t to
err = -EMSGSIZE;
if (skb->len > total_len)
- goto exit_unlock;
+ goto err_free;
odp_vport->len = skb->len;
- err = copy_to_user(dst, skb->data, skb->len) ? -EFAULT : 0;
- goto exit_unlock;
+ return skb;
nla_put_failure:
err = -EMSGSIZE;
-exit_unlock:
- rcu_read_unlock();
+err_free:
kfree_skb(skb);
-exit:
- return err;
+err:
+ return ERR_PTR(err);
}
static struct sk_buff *copy_vport_from_user(struct odp_vport __user *uodp_vport,
@@ -1676,10 +1623,7 @@ error_free_skb:
return ERR_PTR(err);
}
-
-/* Called without any locks (or with RTNL lock).
- * Returns holding vport->dp->mutex.
- */
+/* Called with RTNL lock or RCU read lock. */
static struct vport *lookup_vport(struct odp_vport *odp_vport,
struct nlattr *a[ODP_VPORT_ATTR_MAX + 1])
{
@@ -1687,30 +1631,9 @@ static struct vport *lookup_vport(struct odp_vport *odp_vport,
struct vport *vport;
if (a[ODP_VPORT_ATTR_NAME]) {
- int dp_idx, port_no;
-
- retry:
- rcu_read_lock();
vport = vport_locate(nla_data(a[ODP_VPORT_ATTR_NAME]));
- if (!vport) {
- rcu_read_unlock();
+ if (!vport)
return ERR_PTR(-ENODEV);
- }
- dp_idx = vport->dp->dp_idx;
- port_no = vport->port_no;
- rcu_read_unlock();
-
- dp = get_dp_locked(dp_idx);
- if (!dp)
- goto retry;
-
- vport = get_vport_protected(dp, port_no);
- if (!vport ||
- strcmp(vport_get_name(vport), nla_data(a[ODP_VPORT_ATTR_NAME]))) {
- mutex_unlock(&dp->mutex);
- goto retry;
- }
-
return vport;
} else if (a[ODP_VPORT_ATTR_PORT_NO]) {
u32 port_no = nla_get_u32(a[ODP_VPORT_ATTR_PORT_NO]);
@@ -1718,20 +1641,19 @@ static struct vport *lookup_vport(struct odp_vport *odp_vport,
if (port_no >= DP_MAX_PORTS)
return ERR_PTR(-EINVAL);
- dp = get_dp_locked(odp_vport->dp_idx);
+ dp = get_dp(odp_vport->dp_idx);
if (!dp)
return ERR_PTR(-ENODEV);
vport = get_vport_protected(dp, port_no);
- if (!vport) {
- mutex_unlock(&dp->mutex);
+ if (!vport)
return ERR_PTR(-ENOENT);
- }
return vport;
} else
return ERR_PTR(-EINVAL);
}
+/* Called with RTNL lock. */
static int change_vport(struct vport *vport, struct nlattr *a[ODP_VPORT_ATTR_MAX + 1])
{
int err = 0;
@@ -1749,6 +1671,7 @@ static int attach_vport(struct odp_vport __user *uodp_vport)
struct nlattr *a[ODP_VPORT_ATTR_MAX + 1];
struct odp_vport *odp_vport;
struct vport_parms parms;
+ struct sk_buff *reply;
struct vport *vport;
struct sk_buff *skb;
struct datapath *dp;
@@ -1766,28 +1689,27 @@ static int attach_vport(struct odp_vport __user *uodp_vport)
goto exit_kfree_skb;
rtnl_lock();
-
- dp = get_dp_locked(odp_vport->dp_idx);
+ dp = get_dp(odp_vport->dp_idx);
err = -ENODEV;
if (!dp)
- goto exit_unlock_rtnl;
+ goto exit_unlock;
if (a[ODP_VPORT_ATTR_PORT_NO]) {
port_no = nla_get_u32(a[ODP_VPORT_ATTR_PORT_NO]);
err = -EFBIG;
if (port_no >= DP_MAX_PORTS)
- goto exit_unlock_dp;
+ goto exit_unlock;
vport = get_vport_protected(dp, port_no);
err = -EBUSY;
if (vport)
- goto exit_unlock_dp;
+ goto exit_unlock;
} else {
for (port_no = 1; ; port_no++) {
if (port_no >= DP_MAX_PORTS) {
err = -EFBIG;
- goto exit_unlock_dp;
+ goto exit_unlock;
}
vport = get_vport_protected(dp, port_no);
if (!vport)
@@ -1804,7 +1726,7 @@ static int attach_vport(struct odp_vport __user *uodp_vport)
vport = new_vport(&parms);
err = PTR_ERR(vport);
if (IS_ERR(vport))
- goto exit_unlock_dp;
+ goto exit_unlock;
set_internal_devs_mtu(dp);
dp_sysfs_add_if(vport);
@@ -1812,14 +1734,18 @@ static int attach_vport(struct odp_vport __user *uodp_vport)
err = change_vport(vport, a);
if (err) {
dp_detach_port(vport);
- goto exit_unlock_dp;
+ goto exit_unlock;
}
- err = copy_vport_to_user(uodp_vport, vport, odp_vport->total_len);
+ reply = odp_vport_build_info(vport, odp_vport->total_len);
+ err = PTR_ERR(reply);
+ if (IS_ERR(reply))
+ goto exit_unlock;
+
+ err = copy_to_user(uodp_vport, reply->data, reply->len) ? -EFAULT : 0;
+ kfree_skb(reply);
-exit_unlock_dp:
- mutex_unlock(&dp->mutex);
-exit_unlock_rtnl:
+exit_unlock:
rtnl_unlock();
exit_kfree_skb:
kfree_skb(skb);
@@ -1851,7 +1777,6 @@ static int set_vport(unsigned int cmd, struct odp_vport __user *uodp_vport)
if (!err)
err = change_vport(vport, a);
- mutex_unlock(&vport->dp->mutex);
exit_free:
kfree_skb(skb);
rtnl_unlock();
@@ -1862,7 +1787,6 @@ exit:
static int del_vport(unsigned int cmd, struct odp_vport __user *uodp_vport)
{
struct nlattr *a[ODP_VPORT_ATTR_MAX + 1];
- struct datapath *dp;
struct vport *vport;
struct sk_buff *skb;
int err;
@@ -1875,17 +1799,9 @@ static int del_vport(unsigned int cmd, struct odp_vport __user *uodp_vport)
rtnl_lock();
vport = lookup_vport((struct odp_vport *)skb->data, a);
err = PTR_ERR(vport);
- if (IS_ERR(vport))
- goto exit_free;
- dp = vport->dp;
-
- err = -EINVAL;
- if (vport->port_no == ODPP_LOCAL)
- goto exit_free;
+ if (!IS_ERR(vport))
+ err = dp_detach_port(vport);
- err = dp_detach_port(vport);
- mutex_unlock(&dp->mutex);
-exit_free:
kfree_skb(skb);
rtnl_unlock();
exit:
@@ -1896,6 +1812,7 @@ static int get_vport(struct odp_vport __user *uodp_vport)
{
struct nlattr *a[ODP_VPORT_ATTR_MAX + 1];
struct odp_vport *odp_vport;
+ struct sk_buff *reply;
struct vport *vport;
struct sk_buff *skb;
int err;
@@ -1903,19 +1820,32 @@ static int get_vport(struct odp_vport __user *uodp_vport)
skb = copy_vport_from_user(uodp_vport, a);
err = PTR_ERR(skb);
if (IS_ERR(skb))
- goto exit;
+ goto err;
odp_vport = (struct odp_vport *)skb->data;
+ rcu_read_lock();
vport = lookup_vport(odp_vport, a);
err = PTR_ERR(vport);
if (IS_ERR(vport))
- goto exit_free;
+ goto err_unlock_rcu;
+ reply = odp_vport_build_info(vport, odp_vport->total_len);
+ rcu_read_unlock();
- err = copy_vport_to_user(uodp_vport, vport, odp_vport->total_len);
- mutex_unlock(&vport->dp->mutex);
-exit_free:
+ err = PTR_ERR(reply);
+ if (IS_ERR(reply))
+ goto err_kfree_skb;
+
+ err = copy_to_user(uodp_vport, reply->data, reply->len) ? -EFAULT : 0;
+ kfree_skb(reply);
kfree_skb(skb);
-exit:
+
+ return err;
+
+err_unlock_rcu:
+ rcu_read_unlock();
+err_kfree_skb:
+ kfree_skb(skb);
+err:
return err;
}
@@ -1931,42 +1861,58 @@ static int dump_vport(struct odp_vport __user *uodp_vport)
skb = copy_vport_from_user(uodp_vport, a);
err = PTR_ERR(skb);
if (IS_ERR(skb))
- goto exit;
+ goto err;
odp_vport = (struct odp_vport *)skb->data;
- dp = get_dp_locked(odp_vport->dp_idx);
+ dp = get_dp(odp_vport->dp_idx);
err = -ENODEV;
if (!dp)
- goto exit_free;
+ goto err_kfree_skb;
port_no = 0;
if (a[ODP_VPORT_ATTR_PORT_NO])
port_no = nla_get_u32(a[ODP_VPORT_ATTR_PORT_NO]);
+
+ rcu_read_lock();
for (; port_no < DP_MAX_PORTS; port_no++) {
- struct vport *vport = get_vport_protected(dp, port_no);
- if (vport) {
- err = copy_vport_to_user(uodp_vport, vport, odp_vport->total_len);
- goto exit_unlock_dp;
- }
+ struct sk_buff *skb_out;
+ struct vport *vport;
+ int retval;
+
+ vport = get_vport_protected(dp, port_no);
+ if (!vport)
+ continue;
+
+ skb_out = odp_vport_build_info(vport, odp_vport->total_len);
+ rcu_read_unlock();
+
+ err = PTR_ERR(skb_out);
+ if (IS_ERR(skb_out))
+ goto err_kfree_skb;
+
+ retval = copy_to_user(uodp_vport, skb_out->data, skb_out->len);
+ kfree_skb(skb_out);
+ kfree_skb(skb);
+
+ return retval ? -EFAULT : 0;
}
+ rcu_read_unlock();
err = -ENODEV;
-exit_unlock_dp:
- mutex_unlock(&dp->mutex);
-exit_free:
+err_kfree_skb:
kfree_skb(skb);
-exit:
+err:
return err;
}
static long openvswitch_ioctl(struct file *f, unsigned int cmd,
unsigned long argp)
{
- int dp_idx = iminor(f->f_dentry->d_inode);
- struct datapath *dp;
int listeners;
int err;
+ genl_lock();
+
/* Handle commands with special locking requirements up front. */
switch (cmd) {
case ODP_DP_NEW:
@@ -2032,11 +1978,6 @@ static long openvswitch_ioctl(struct file *f, unsigned int cmd,
goto exit;
}
- dp = get_dp_locked(dp_idx);
- err = -ENODEV;
- if (!dp)
- goto exit;
-
switch (cmd) {
case ODP_GET_LISTEN_MASK:
err = put_user(get_listen_mask(f), (int __user *)argp);
@@ -2057,8 +1998,8 @@ static long openvswitch_ioctl(struct file *f, unsigned int cmd,
err = -ENOIOCTLCMD;
break;
}
- mutex_unlock(&dp->mutex);
exit:
+ genl_unlock();
return err;
}
@@ -2107,49 +2048,58 @@ static long openvswitch_compat_ioctl(struct file *f, unsigned int cmd, unsigned
}
#endif
+static struct sk_buff *openvswitch_try_read(struct file *f, struct datapath *dp)
+{
+ int listeners = get_listen_mask(f);
+ int i;
+
+ for (i = 0; i < DP_N_QUEUES; i++) {
+ if (listeners & (1 << i)) {
+ struct sk_buff *skb = skb_dequeue(&dp->queues[i]);
+ if (skb)
+ return skb;
+ }
+ }
+
+ if (f->f_flags & O_NONBLOCK)
+ return ERR_PTR(-EAGAIN);
+
+ wait_event_interruptible(dp->waitqueue,
+ dp_has_packet_of_interest(dp, listeners));
+
+ if (signal_pending(current))
+ return ERR_PTR(-ERESTARTSYS);
+
+ return NULL;
+}
+
static ssize_t openvswitch_read(struct file *f, char __user *buf,
size_t nbytes, loff_t *ppos)
{
- int listeners = get_listen_mask(f);
int dp_idx = iminor(f->f_dentry->d_inode);
- struct datapath *dp = get_dp_locked(dp_idx);
+ struct datapath *dp;
struct sk_buff *skb;
struct iovec iov;
int retval;
- if (!dp)
- return -ENODEV;
-
- if (nbytes == 0 || !listeners)
- return 0;
+ genl_lock();
- for (;;) {
- int i;
-
- for (i = 0; i < DP_N_QUEUES; i++) {
- if (listeners & (1 << i)) {
- skb = skb_dequeue(&dp->queues[i]);
- if (skb)
- goto success;
- }
- }
+ dp = get_dp(dp_idx);
+ retval = -ENODEV;
+ if (!dp)
+ goto error;
- if (f->f_flags & O_NONBLOCK) {
- retval = -EAGAIN;
- goto error;
- }
+ retval = 0;
+ if (nbytes == 0 || !get_listen_mask(f))
+ goto error;
- wait_event_interruptible(dp->waitqueue,
- dp_has_packet_of_interest(dp,
- listeners));
+ do {
+ skb = openvswitch_try_read(f, dp);
+ } while (!skb);
- if (signal_pending(current)) {
- retval = -ERESTARTSYS;
- goto error;
- }
- }
-success:
- mutex_unlock(&dp->mutex);
+ genl_unlock();
+ if (IS_ERR(skb))
+ return PTR_ERR(skb);
iov.iov_base = buf;
iov.iov_len = min_t(size_t, skb->len, nbytes);
@@ -2161,25 +2111,28 @@ success:
return retval;
error:
- mutex_unlock(&dp->mutex);
+ genl_unlock();
return retval;
}
static unsigned int openvswitch_poll(struct file *file, poll_table *wait)
{
int dp_idx = iminor(file->f_dentry->d_inode);
- struct datapath *dp = get_dp_locked(dp_idx);
+ struct datapath *dp;
unsigned int mask;
+ genl_lock();
+ dp = get_dp(dp_idx);
if (dp) {
mask = 0;
poll_wait(file, &dp->waitqueue, wait);
if (dp_has_packet_of_interest(dp, get_listen_mask(file)))
mask |= POLLIN | POLLRDNORM;
- mutex_unlock(&dp->mutex);
} else {
mask = POLLIN | POLLRDNORM | POLLHUP;
}
+ genl_unlock();
+
return mask;
}
diff --git a/datapath/datapath.h b/datapath/datapath.h
index d8b7a6d..deeec9a 100644
--- a/datapath/datapath.h
+++ b/datapath/datapath.h
@@ -60,25 +60,27 @@ struct dp_stats_percpu {
/**
* struct datapath - datapath for flow-based packet switching
* @rcu: RCU callback head for deferred destruction.
- * @mutex: Mutual exclusion for ioctls.
* @dp_idx: Datapath number (index into the dps[] array in datapath.c).
- * @ifobj: Represents /sys/class/net/<devname>/brif.
+ * @ifobj: Represents /sys/class/net/<devname>/brif. Protected by RTNL.
* @drop_frags: Drop all IP fragments if nonzero.
* @queues: %DP_N_QUEUES sets of queued packets for userspace to handle.
* @waitqueue: Waitqueue, for waiting for new packets in @queues.
* @n_flows: Number of flows currently in flow table.
- * @table: Current flow table.
+ * @table: Current flow table. Protected by genl_lock and RCU.
* @ports: Map from port number to &struct vport. %ODPP_LOCAL port
- * always exists, other ports may be %NULL.
- * @port_list: List of all ports in @ports in arbitrary order.
+ * always exists, other ports may be %NULL. Protected by RTNL and RCU.
+ * @port_list: List of all ports in @ports in arbitrary order. RTNL required
+ * to iterate or modify.
* @stats_percpu: Per-CPU datapath statistics.
* @sflow_probability: Number of packets out of UINT_MAX to sample to the
* %ODPL_SFLOW queue, e.g. (@sflow_probability/UINT_MAX) is the probability of
* sampling a given packet.
+ *
+ * Context: See the comment on locking at the top of datapath.c for additional
+ * locking information.
*/
struct datapath {
struct rcu_head rcu;
- struct mutex mutex;
int dp_idx;
struct kobject ifobj;
diff --git a/datapath/dp_notify.c b/datapath/dp_notify.c
index 1415833..8c54d68 100644
--- a/datapath/dp_notify.c
+++ b/datapath/dp_notify.c
@@ -1,6 +1,6 @@
/*
* Distributed under the terms of the GNU GPL version 2.
- * Copyright (c) 2007, 2008, 2009, 2010 Nicira Networks.
+ * Copyright (c) 2007, 2008, 2009, 2010, 2011 Nicira Networks.
*
* Significant portions of this file may be copied from parts of the Linux
* kernel, by Linus Torvalds and others.
@@ -33,19 +33,14 @@ static int dp_device_event(struct notifier_block *unused, unsigned long event,
switch (event) {
case NETDEV_UNREGISTER:
- if (!is_internal_dev(dev)) {
- mutex_lock(&dp->mutex);
+ if (!is_internal_dev(dev))
dp_detach_port(vport);
- mutex_unlock(&dp->mutex);
- }
break;
case NETDEV_CHANGENAME:
if (vport->port_no != ODPP_LOCAL) {
- mutex_lock(&dp->mutex);
dp_sysfs_del_if(vport);
dp_sysfs_add_if(vport);
- mutex_unlock(&dp->mutex);
}
break;
diff --git a/datapath/linux-2.6/Modules.mk b/datapath/linux-2.6/Modules.mk
index 29cbd93..c9f5971 100644
--- a/datapath/linux-2.6/Modules.mk
+++ b/datapath/linux-2.6/Modules.mk
@@ -15,6 +15,7 @@ openvswitch_headers += \
linux-2.6/compat-2.6/include/linux/cpumask.h \
linux-2.6/compat-2.6/include/linux/dmi.h \
linux-2.6/compat-2.6/include/linux/err.h \
+ linux-2.6/compat-2.6/include/linux/genetlink.h \
linux-2.6/compat-2.6/include/linux/icmp.h \
linux-2.6/compat-2.6/include/linux/if.h \
linux-2.6/compat-2.6/include/linux/if_arp.h \
diff --git a/datapath/linux-2.6/compat-2.6/include/linux/genetlink.h b/datapath/linux-2.6/compat-2.6/include/linux/genetlink.h
new file mode 100644
index 0000000..e45d085
--- /dev/null
+++ b/datapath/linux-2.6/compat-2.6/include/linux/genetlink.h
@@ -0,0 +1,15 @@
+#ifndef __GENETLINK_WRAPPER_H
+#define __GENETLINK_WRAPPER_H 1
+
+#include_next <linux/genetlink.h>
+
+#ifdef CONFIG_PROVE_LOCKING
+/* No version of the kernel has this function, but our locking scheme depends
+ * on genl_mutex so for clarity we use it where appropriate. */
+static inline int lockdep_genl_is_held(void)
+{
+ return 1;
+}
+#endif
+
+#endif /* linux/genetlink.h wrapper */
diff --git a/datapath/table.c b/datapath/table.c
index 35a532e..47fa016 100644
--- a/datapath/table.c
+++ b/datapath/table.c
@@ -10,6 +10,7 @@
#include "datapath.h"
#include "table.h"
+#include <linux/genetlink.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/mm.h>
@@ -30,6 +31,17 @@ struct tbl_bucket {
struct tbl_node *objs[];
};
+static struct tbl_bucket *get_bucket(struct tbl_bucket __rcu *bucket)
+{
+ return rcu_dereference_check(bucket, rcu_read_lock_held() ||
+ lockdep_genl_is_held());
+}
+
+static struct tbl_bucket *get_bucket_protected(struct tbl_bucket __rcu *bucket)
+{
+ return rcu_dereference_protected(bucket, lockdep_genl_is_held());
+}
+
static inline int bucket_size(int n_objs)
{
return sizeof(struct tbl_bucket) + sizeof(struct tbl_node *) * n_objs;
@@ -196,7 +208,7 @@ struct tbl_node *tbl_lookup(struct tbl *table, void *target, u32 hash,
int (*cmp)(const struct tbl_node *, void *))
{
struct tbl_bucket __rcu **bucketp = find_bucket(table, hash);
- struct tbl_bucket *bucket = rcu_dereference(*bucketp);
+ struct tbl_bucket *bucket = get_bucket(*bucketp);
int index;
if (!bucket)
@@ -237,7 +249,7 @@ int tbl_foreach(struct tbl *table,
struct tbl_bucket *bucket;
unsigned int i;
- bucket = rcu_dereference(l2[l2_idx]);
+ bucket = get_bucket(l2[l2_idx]);
if (!bucket)
continue;
@@ -282,7 +294,7 @@ struct tbl_node *tbl_next(struct tbl *table, u32 *bucketp, u32 *objp)
for (l2_idx = s_l2_idx; l2_idx < TBL_L2_SIZE; l2_idx++) {
struct tbl_bucket *bucket;
- bucket = rcu_dereference(l2[l2_idx]);
+ bucket = get_bucket_protected(l2[l2_idx]);
if (bucket && s_obj < bucket->n_objs) {
*bucketp = (l1_idx << TBL_L1_SHIFT) + l2_idx;
*objp = s_obj + 1;
@@ -371,7 +383,7 @@ static void free_bucket_rcu(struct rcu_head *rcu)
int tbl_insert(struct tbl *table, struct tbl_node *target, u32 hash)
{
struct tbl_bucket __rcu **oldp = find_bucket(table, hash);
- struct tbl_bucket *old = rcu_dereference(*oldp);
+ struct tbl_bucket *old = get_bucket_protected(*oldp);
unsigned int n = old ? old->n_objs : 0;
struct tbl_bucket *new = bucket_alloc(n + 1);
@@ -409,7 +421,7 @@ int tbl_insert(struct tbl *table, struct tbl_node *target, u32 hash)
int tbl_remove(struct tbl *table, struct tbl_node *target)
{
struct tbl_bucket __rcu **oldp = find_bucket(table, target->hash);
- struct tbl_bucket *old = rcu_dereference(*oldp);
+ struct tbl_bucket *old = get_bucket_protected(*oldp);
unsigned int n = old->n_objs;
struct tbl_bucket *new;
diff --git a/datapath/vport.c b/datapath/vport.c
index 574e3ec..517e871 100644
--- a/datapath/vport.c
+++ b/datapath/vport.c
@@ -270,7 +270,7 @@ int vport_set_options(struct vport *vport, struct nlattr *options)
}
/**
- * vport_del - delete existing vport device (for kernel callers)
+ * vport_del - delete existing vport device
*
* @vport: vport to delete.
*
@@ -340,7 +340,7 @@ int vport_set_addr(struct vport *vport, const unsigned char *addr)
}
/**
- * 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
@@ -348,7 +348,9 @@ int vport_set_addr(struct vport *vport, const unsigned char *addr)
* 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)
{
@@ -382,8 +384,7 @@ const char *vport_get_name(const struct vport *vport)
*
* @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)
{
@@ -432,12 +433,14 @@ static int vport_call_get_stats(struct vport *vport, struct rtnl_link_stats64 *s
}
/**
- * 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)
{
@@ -519,8 +522,9 @@ 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)
{
@@ -532,8 +536,9 @@ 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)
{
@@ -545,8 +550,9 @@ 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)
{
@@ -560,8 +566,9 @@ 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)
{
@@ -579,8 +586,9 @@ 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)
{
@@ -593,12 +601,13 @@ 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.
+ *
+ * Must be called with RTNL lock or rcu_read_lock.
*/
int vport_get_mtu(const struct vport *vport)
{
@@ -613,11 +622,12 @@ int vport_get_mtu(const struct vport *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.
+ *
+ * Must be called with RTNL lock or rcu_read_lock.
*/
int vport_get_options(const struct vport *vport, struct sk_buff *skb)
{
--
1.7.1
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