[NETLINK]: Directly return -EINTR from netlink_dump_start()

Now that all users of netlink_dump_start() use netlink_run_queue()
to process the receive queue, it is possible to return -EINTR from
netlink_dump_start() directly, therefore simplying the callers.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 18 insertions, 34 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 14241ada41a1..fa5f938b37ee 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -859,7 +859,6 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
         int min_len;
         int family;
         int type;
-        int err;
 
         type = nlh->nlmsg_type;
         if (type > RTM_MAX)
@@ -888,10 +887,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 if (dumpit == NULL)
                         return -EINVAL;
 
-                err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
-                if (err == 0)
-                        err = -EINTR;
-                return err;
+                return netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
         }
 
         memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 7dd97c5969b3..0148f0e34ceb 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -818,8 +818,6 @@ static int inet_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 return -ENOENT;
 
         if (nlh->nlmsg_flags & NLM_F_DUMP) {
-                int err;
-
                 if (nlmsg_attrlen(nlh, hdrlen)) {
                         struct nlattr *attr;
 
@@ -831,11 +829,8 @@ static int inet_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                                 return -EINVAL;
                 }
 
-                err = netlink_dump_start(idiagnl, skb, nlh,
-                                         inet_diag_dump, NULL);
-                if (err == 0)
-                        err = -EINTR;
-                return err;
+                return netlink_dump_start(idiagnl, skb, nlh,
+                                          inet_diag_dump, NULL);
         }
 
         return inet_diag_get_exact(skb, nlh);
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 443ba7753a33..e5267305bb48 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -724,11 +724,8 @@ ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb,
                 if (NFNL_MSG_TYPE(nlh->nlmsg_type) == IPCTNL_MSG_CT_GET_CTRZERO)
                         return -ENOTSUPP;
 #endif
-                err = netlink_dump_start(ctnl, skb, nlh, ctnetlink_dump_table,
-                                         ctnetlink_done);
-                if (err == 0)
-                        err = -EINTR;
-                return err;
+                return netlink_dump_start(ctnl, skb, nlh, ctnetlink_dump_table,
+                                          ctnetlink_done);
         }
 
         if (nfattr_bad_size(cda, CTA_MAX, cta_min))
@@ -1266,12 +1263,9 @@ ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb,
                 return -EINVAL;
 
         if (nlh->nlmsg_flags & NLM_F_DUMP) {
-                err = netlink_dump_start(ctnl, skb, nlh,
-                                         ctnetlink_exp_dump_table,
-                                         ctnetlink_done);
-                if (err == 0)
-                        err = -EINTR;
-                return err;
+                return netlink_dump_start(ctnl, skb, nlh,
+                                          ctnetlink_exp_dump_table,
+                                          ctnetlink_done);
         }
 
         if (cda[CTA_EXPECT_MASTER-1])
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 1823b7c63156..2cbf1682f63d 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1426,7 +1426,12 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 
         netlink_dump(sk);
         sock_put(sk);
-        return 0;
+
+        /* We successfully started a dump, by returning -EINTR we
+         * signal the queue mangement to interrupt processing of
+         * any netlink messages so userspace gets a chance to read
+         * the results. */
+        return -EINTR;
 }
 
 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 1b897bc92e61..fac2e7a6dbe4 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -323,11 +323,8 @@ static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 if (ops->dumpit == NULL)
                         return -EOPNOTSUPP;
 
-                err = netlink_dump_start(genl_sock, skb, nlh,
-                                         ops->dumpit, ops->done);
-                if (err == 0)
-                        err = -EINTR;
-                return err;
+                return netlink_dump_start(genl_sock, skb, nlh,
+                                          ops->dumpit, ops->done);
         }
 
         if (ops->doit == NULL)
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 5e52d6275bad..2ff968373f1c 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1856,7 +1856,7 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
         struct rtattr *xfrma[XFRMA_MAX];
         struct xfrm_link *link;
-        int type, min_len, err;
+        int type, min_len;
 
         type = nlh->nlmsg_type;
         if (type > XFRM_MSG_MAX)
@@ -1875,10 +1875,7 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 if (link->dump == NULL)
                         return -EINVAL;
 
-                err = netlink_dump_start(xfrm_nl, skb, nlh, link->dump, NULL);
-                if (err == 0)
-                        err = -EINTR;
-                return err;
+                return netlink_dump_start(xfrm_nl, skb, nlh, link->dump, NULL);
         }
 
         memset(xfrma, 0, sizeof(xfrma));