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From:   Stefano Stabellini <sstabellini@kernel.org>
To:     boris.ostrovsky@oracle.com, jgross@suse.com
Cc:     sstabellini@kernel.org, xen-devel@lists.xenproject.org,
        linux-kernel@vger.kernel.org,
        Stefano Stabellini <stefano@aporeto.com>
Subject: [PATCH v2 2/2] pvcalls-front: wait for other operations to return when release passive sockets
Date:   Mon, 12 Feb 2018 18:13:47 -0800
Message-Id: <1518488027-22386-2-git-send-email-sstabellini@kernel.org>
In-Reply-To: <1518488027-22386-1-git-send-email-sstabellini@kernel.org>
References: <alpine.DEB.2.10.1802121812500.3704@sstabellini-ThinkPad-X260>
 <1518488027-22386-1-git-send-email-sstabellini@kernel.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Passive sockets can have ongoing operations on them, specifically, we
have two wait_event_interruptable calls in pvcalls_front_accept.

Add two wake_up calls in pvcalls_front_release, then wait for the
potential waiters to return and release the sock_mapping refcount.

Signed-off-by: Stefano Stabellini <stefano@aporeto.com>
Acked-by: Juergen Gross <jgross@suse.com>
---
 drivers/xen/pvcalls-front.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 163bf8c..7e67fb7 100644
--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -1020,6 +1020,12 @@ int pvcalls_front_release(struct socket *sock)
 
 		pvcalls_front_free_map(bedata, map);
 	} else {
+		wake_up(&bedata->inflight_req);
+		wake_up(&map->passive.inflight_accept_req);
+
+		while (atomic_read(&map->refcount) > 1)
+			cpu_relax();
+
 		spin_lock(&bedata->socket_lock);
 		list_del(&map->list);
 		spin_unlock(&bedata->socket_lock);
-- 
1.9.1