[RTNETLINK]: Hold rtnl_mutex during netlink dump callbacks
Hold rtnl_mutex during the entire netlink dump operation. This allows
to simplify locking in the dump callbacks, since they can now rely on
that no concurrent changes happen.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 648a7b6..62f5c7f 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -859,6 +859,7 @@
int min_len;
int family;
int type;
+ int err;
type = nlh->nlmsg_type;
if (type > RTM_MAX)
@@ -887,7 +888,10 @@
if (dumpit == NULL)
return -EOPNOTSUPP;
- return netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
+ __rtnl_unlock();
+ err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
+ rtnl_lock();
+ return err;
}
memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
@@ -972,7 +976,7 @@
panic("rtnetlink_init: cannot allocate rta_buf\n");
rtnl = netlink_kernel_create(NETLINK_ROUTE, RTNLGRP_MAX, rtnetlink_rcv,
- NULL, THIS_MODULE);
+ &rtnl_mutex, THIS_MODULE);
if (rtnl == NULL)
panic("rtnetlink_init: cannot initialize rtnetlink\n");
netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);