diff mbox

[v3,1/2] genl: Fix genl dumpit() locking.

Message ID 1377287095-13245-1-git-send-email-pshelar@nicira.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Pravin B Shelar Aug. 23, 2013, 7:44 p.m. UTC
In case of genl-family with parallel ops off, dumpif() callback
is expected to run under genl_lock, But commit def3117493eafd9df
(genl: Allow concurrent genl callbacks.) changed this behaviour
where only first dumpit() op was called under genl-lock.
For subsequent dump, only nlk->cb_lock was taken.
Following patch fixes it by defining locked dumpit() and done()
callback which takes care of genl-locking.

CC: Jesse Gross <jesse@nicira.com>
CC: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
---
v2-v3:
coding style fix.
v1-v2:
No change.
---
 net/netlink/genetlink.c |   51 ++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 46 insertions(+), 5 deletions(-)

Comments

David Miller Aug. 28, 2013, 9:19 p.m. UTC | #1
From: Pravin B Shelar <pshelar@nicira.com>
Date: Fri, 23 Aug 2013 12:44:55 -0700

> In case of genl-family with parallel ops off, dumpif() callback
> is expected to run under genl_lock, But commit def3117493eafd9df
> (genl: Allow concurrent genl callbacks.) changed this behaviour
> where only first dumpit() op was called under genl-lock.
> For subsequent dump, only nlk->cb_lock was taken.
> Following patch fixes it by defining locked dumpit() and done()
> callback which takes care of genl-locking.
> 
> CC: Jesse Gross <jesse@nicira.com>
> CC: Johannes Berg <johannes.berg@intel.com>
> Signed-off-by: Pravin B Shelar <pshelar@nicira.com>

Applied, and queued up for -stable.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index f85f8a2..f09d387 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -544,6 +544,30 @@  void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
 }
 EXPORT_SYMBOL(genlmsg_put);
 
+static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct genl_ops *ops = cb->data;
+	int rc;
+
+	genl_lock();
+	rc = ops->dumpit(skb, cb);
+	genl_unlock();
+	return rc;
+}
+
+static int genl_lock_done(struct netlink_callback *cb)
+{
+	struct genl_ops *ops = cb->data;
+	int rc = 0;
+
+	if (ops->done) {
+		genl_lock();
+		rc = ops->done(cb);
+		genl_unlock();
+	}
+	return rc;
+}
+
 static int genl_family_rcv_msg(struct genl_family *family,
 			       struct sk_buff *skb,
 			       struct nlmsghdr *nlh)
@@ -572,15 +596,32 @@  static int genl_family_rcv_msg(struct genl_family *family,
 		return -EPERM;
 
 	if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
-		struct netlink_dump_control c = {
-			.dump = ops->dumpit,
-			.done = ops->done,
-		};
+		int rc;
 
 		if (ops->dumpit == NULL)
 			return -EOPNOTSUPP;
 
-		return netlink_dump_start(net->genl_sock, skb, nlh, &c);
+		if (!family->parallel_ops) {
+			struct netlink_dump_control c = {
+				.data = ops,
+				.dump = genl_lock_dumpit,
+				.done = genl_lock_done,
+			};
+
+			genl_unlock();
+			rc = netlink_dump_start(net->genl_sock, skb, nlh, &c);
+			genl_lock();
+
+		} else {
+			struct netlink_dump_control c = {
+				.dump = ops->dumpit,
+				.done = ops->done,
+			};
+
+			rc = netlink_dump_start(net->genl_sock, skb, nlh, &c);
+		}
+
+		return rc;
 	}
 
 	if (ops->doit == NULL)