net/smc: no socket state changes in tasklet context
Several state changes occur during SMC socket closing. Currently
state changes triggered locally occur in process context with
lock_sock() taken while state changes triggered by peer occur in
tasklet context with bh_lock_sock() taken. bh_lock_sock() does not
wait till a lock_sock(() task in process context is finished. This
may lead to races in socket state transitions resulting in dangling
SMC-sockets, or it may lead to duplicate SMC socket freeing.
This patch introduces a closing worker to run all state changes under
lock_sock().
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 0eac633..65020e9 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -316,7 +316,7 @@
smc = container_of(conn, struct smc_sock, conn);
sock_hold(&smc->sk);
__smc_lgr_unregister_conn(conn);
- smc_close_active_abort(smc);
+ schedule_work(&conn->close_work);
sock_put(&smc->sk);
node = rb_first(&lgr->conns_all);
}