From c8d0f63c15851e7d6f41b455d74e4b2b0a862a09 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 19 Jan 2018 14:36:29 +0100 Subject: [PATCH] iscsi-target: make sure to wake up sleeping login worker commit 1c130ae00b769a2e2df41bad3d6051ee8234b636 upstream. Mike Christie reports: Starting in 4.14 iscsi logins will fail around 50% of the time. Problem appears to be that iscsi_target_sk_data_ready() callback may return without doing anything in case it finds the login work queue is still blocked in sock_recvmsg(). Nicholas Bellinger says: It would indicate users providing their own ->sk_data_ready() callback must be responsible for waking up a kthread context blocked on sock_recvmsg(..., MSG_WAITALL), when a second ->sk_data_ready() is received before the first sock_recvmsg(..., MSG_WAITALL) completes. So, do this and invoke the original data_ready() callback -- in case of tcp sockets this takes care of waking the thread. Disclaimer: I do not understand why this problem did not show up before tcp prequeue removal. (Drop WARN_ON usage - nab) Reported-by: Mike Christie Bisected-by: Mike Christie Tested-by: Mike Christie Diagnosed-by: Nicholas Bellinger Fixes: e7942d0633c4 ("tcp: remove prequeue support") Signed-off-by: Florian Westphal Cc: stable@vger.kernel.org # 4.14+ Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/target/iscsi/iscsi_target_nego.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c index 7a6751fecd32..87248a2512e5 100644 --- a/drivers/target/iscsi/iscsi_target_nego.c +++ b/drivers/target/iscsi/iscsi_target_nego.c @@ -432,6 +432,9 @@ static void iscsi_target_sk_data_ready(struct sock *sk) if (test_and_set_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags)) { write_unlock_bh(&sk->sk_callback_lock); pr_debug("Got LOGIN_FLAGS_READ_ACTIVE=1, conn: %p >>>>\n", conn); + if (iscsi_target_sk_data_ready == conn->orig_data_ready) + return; + conn->orig_data_ready(sk); return; } -- 2.20.1