Commit e9f02985 authored by Ricardo Labiaga's avatar Ricardo Labiaga Committed by Trond Myklebust
Browse files

nfs41: sunrpc: xprt_alloc_bc_request() should not use spin_lock_bh() 



xprt_alloc_bc_request() is always called in soft interrupt context.
Grab the spin_lock instead of the bottom half spin_lock.  Softirqs
do not preempt other softirqs running on the same processor, so there
is no need to disable bottom halves.

Signed-off-by: default avatarRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 578e4585

net/sunrpc/backchannel_rqst.c

+5 −2
Original line number Diff line number Diff line
@@ -211,6 +211,9 @@ EXPORT_SYMBOL(xprt_destroy_backchannel); 
 * has been preallocated as well.  Use xprt_alloc_bc_request to allocate

 * to this request.  Use xprt_free_bc_request to return it.

 *

 * We know that we're called in soft interrupt context, grab the spin_lock

 * since there is no need to grab the bottom half spin_lock.

 *

 * Return an available rpc_rqst, otherwise NULL if non are available.

 */

struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt)
@@ -218,7 +221,7 @@ struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt) 
	struct rpc_rqst *req;



	dprintk("RPC:       allocate a backchannel request\n");

	spin_lock_bh(&xprt->bc_pa_lock);

	spin_lock(&xprt->bc_pa_lock);

	if (!list_empty(&xprt->bc_pa_list)) {

		req = list_first_entry(&xprt->bc_pa_list, struct rpc_rqst,

				rq_bc_pa_list);
@@ -226,7 +229,7 @@ struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt) 
	} else {

		req = NULL;

	}

	spin_unlock_bh(&xprt->bc_pa_lock);

	spin_unlock(&xprt->bc_pa_lock);



	if (req != NULL) {

		set_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);

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