net/tls: sleeping function from invalid context

HW unhash within mutex for registered tls devices cause sleep
when called from tcp_set_state for TCP_CLOSE. Release lock and
re-acquire after function call with ref count incr/dec.
defined kref and fp release for tls_device to ensure device
is not released outside lock.

BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:748
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/7
INFO: lockdep is turned off.
CPU: 7 PID: 0 Comm: swapper/7 Tainted: G        W  O
Call Trace:
 <IRQ>
 dump_stack+0x5e/0x8b
 ___might_sleep+0x222/0x260
 __mutex_lock+0x5c/0xa50
 ? vprintk_emit+0x1f3/0x440
 ? kmem_cache_free+0x22d/0x2a0
 ? tls_hw_unhash+0x2f/0x80
 ? printk+0x52/0x6e
 ? tls_hw_unhash+0x2f/0x80
 tls_hw_unhash+0x2f/0x80
 tcp_set_state+0x5f/0x180
 tcp_done+0x2e/0xe0
 tcp_rcv_state_process+0x92c/0xdd3
 ? lock_acquire+0xf5/0x1f0
 ? tcp_v4_rcv+0xa7c/0xbe0
 ? tcp_v4_do_rcv+0x70/0x1e0

Signed-off-by: Atul Gupta <atul.gupta@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tls.h

@@ -76,6 +76,10 @@
  *
  * void (*unhash)(struct tls_device *device, struct sock *sk);
  *     This function cleans listen state set by Inline TLS driver
+ *
+ * void (*release)(struct kref *kref);
+ *     Release the registered device and allocated resources
+ * @kref: Number of reference to tls_device
  */
 struct tls_device {
 	char name[TLS_DEVICE_NAME_MAX];
@@ -83,6 +87,8 @@ struct tls_device {
 	int  (*feature)(struct tls_device *device);
 	int  (*hash)(struct tls_device *device, struct sock *sk);
 	void (*unhash)(struct tls_device *device, struct sock *sk);
+	void (*release)(struct kref *kref);
+	struct kref kref;
 };
 
 enum {