sunrpc: drop BKL around wrap and unwrap

We don't need the BKL when wrapping and unwrapping; and experiments by Avishay
Traeger have found that permitting multiple encryption and decryption
operations to proceed in parallel can provide significant performance
improvements.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Avishay Traeger <atraeger@cs.sunysb.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 17d460f..baf4096d 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -999,7 +999,9 @@
 	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
 	*p++ = htonl(rqstp->rq_seqno);
 
+	lock_kernel();
 	status = encode(rqstp, p, obj);
+	unlock_kernel();
 	if (status)
 		return status;
 
@@ -1093,7 +1095,9 @@
 	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
 	*p++ = htonl(rqstp->rq_seqno);
 
+	lock_kernel();
 	status = encode(rqstp, p, obj);
+	unlock_kernel();
 	if (status)
 		return status;
 
@@ -1152,12 +1156,16 @@
 		/* The spec seems a little ambiguous here, but I think that not
 		 * wrapping context destruction requests makes the most sense.
 		 */
+		lock_kernel();
 		status = encode(rqstp, p, obj);
+		unlock_kernel();
 		goto out;
 	}
 	switch (gss_cred->gc_service) {
 		case RPC_GSS_SVC_NONE:
+			lock_kernel();
 			status = encode(rqstp, p, obj);
+			unlock_kernel();
 			break;
 		case RPC_GSS_SVC_INTEGRITY:
 			status = gss_wrap_req_integ(cred, ctx, encode,
@@ -1273,7 +1281,9 @@
 	cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
 						+ (savedlen - head->iov_len);
 out_decode:
+	lock_kernel();
 	status = decode(rqstp, p, obj);
+	unlock_kernel();
 out:
 	gss_put_ctx(ctx);
 	dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,