netns: fix error code when the nsid is already used

When the user tries to assign a specific nsid, idr_alloc() is called with
the range [nsid, nsid+1]. If this nsid is already used, idr_alloc() returns
ENOSPC (No space left on device). In our case, it's better to return
EEXIST to make it clear that the nsid is not available.

CC: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 1f60c180e2dedbcec2e5c684713421dbc695b223..2178db8e47cd332a3ca0de850cd574a5acaadb10 100644 (file)
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -642,6 +642,7 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
                rtnl_net_notifyid(net, RTM_NEWNSID, err);
                err = 0;
        } else if (err == -ENOSPC && nsid >= 0) {
+               err = -EEXIST;
                NL_SET_BAD_ATTR(extack, tb[NETNSA_NSID]);
                NL_SET_ERR_MSG(extack, "The specified nsid is already used");
        }