4.14-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit e6587cdbd732eacb4c7ce592ed46f7bbcefb655f ]
When a connection is closing we receive on pvcalls_sk_state_change notification. Instead of setting the connection as closed immediately (-ENOTCONN), let's read one more time from it: pvcalls_conn_back_read will set the connection as closed when necessary.
That way, we avoid races between pvcalls_sk_state_change and pvcalls_back_ioworker.
Signed-off-by: Stefano Stabellini stefanos@xilinx.com Reviewed-by: Boris Ostrovsky boris.ostrovsky@oracle.com Signed-off-by: Boris Ostrovsky boris.ostrovsky@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/xen/pvcalls-back.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index 169293c25a915..7185ebb63bd53 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -164,9 +164,10 @@ static void pvcalls_conn_back_read(void *opaque)
/* write the data, then modify the indexes */ virt_wmb(); - if (ret < 0) + if (ret < 0) { + atomic_set(&map->read, 0); intf->in_error = ret; - else + } else intf->in_prod = prod + ret; /* update the indexes, then notify the other end */ virt_wmb(); @@ -296,7 +297,7 @@ static void pvcalls_sk_state_change(struct sock *sock) return;
intf = map->ring; - intf->in_error = -ENOTCONN; + atomic_inc(&map->read); notify_remote_via_irq(map->irq); }