SUNRPC: Distinguish between the slot allocation list and receive queue
authorTrond Myklebust <trond.myklebust@hammerspace.com>
Wed, 8 Aug 2018 13:23:32 +0000 (09:23 -0400)
committerTrond Myklebust <trond.myklebust@hammerspace.com>
Sun, 30 Sep 2018 19:35:14 +0000 (15:35 -0400)
When storing a struct rpc_rqst on the slot allocation list, we currently
use the same field 'rq_list' as we use to store the request on the
receive queue. Since the structure is never on both lists at the same
time, this is OK.
However, for clarity, let's make that a union with different names for
the different lists so that we can more easily distinguish between
the two states.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
include/linux/sunrpc/xprt.h
net/sunrpc/xprt.c

index 4fa2af0..9cec2d0 100644 (file)
@@ -82,7 +82,11 @@ struct rpc_rqst {
        struct page             **rq_enc_pages; /* scratch pages for use by
                                                   gss privacy code */
        void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
-       struct list_head        rq_list;
+
+       union {
+               struct list_head        rq_list;        /* Slot allocation list */
+               struct list_head        rq_recv;        /* Receive queue */
+       };
 
        void                    *rq_buffer;     /* Call XDR encode buffer */
        size_t                  rq_callsize;
@@ -249,7 +253,8 @@ struct rpc_xprt {
        struct list_head        bc_pa_list;     /* List of preallocated
                                                 * backchannel rpc_rqst's */
 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
-       struct list_head        recv;
+
+       struct list_head        recv_queue;     /* Receive queue */
 
        struct {
                unsigned long           bind_count,     /* total number of binds */
index a6a33c1..d527dc0 100644 (file)
@@ -708,7 +708,7 @@ static void
 xprt_schedule_autodisconnect(struct rpc_xprt *xprt)
        __must_hold(&xprt->transport_lock)
 {
-       if (list_empty(&xprt->recv) && xprt_has_timer(xprt))
+       if (list_empty(&xprt->recv_queue) && xprt_has_timer(xprt))
                mod_timer(&xprt->timer, xprt->last_used + xprt->idle_timeout);
 }
 
@@ -718,7 +718,7 @@ xprt_init_autodisconnect(struct timer_list *t)
        struct rpc_xprt *xprt = from_timer(xprt, t, timer);
 
        spin_lock(&xprt->transport_lock);
-       if (!list_empty(&xprt->recv))
+       if (!list_empty(&xprt->recv_queue))
                goto out_abort;
        /* Reset xprt->last_used to avoid connect/autodisconnect cycling */
        xprt->last_used = jiffies;
@@ -848,7 +848,7 @@ struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid)
 {
        struct rpc_rqst *entry;
 
-       list_for_each_entry(entry, &xprt->recv, rq_list)
+       list_for_each_entry(entry, &xprt->recv_queue, rq_recv)
                if (entry->rq_xid == xid) {
                        trace_xprt_lookup_rqst(xprt, xid, 0);
                        entry->rq_rtt = ktime_sub(ktime_get(), entry->rq_xtime);
@@ -938,7 +938,7 @@ xprt_request_enqueue_receive(struct rpc_task *task)
                        sizeof(req->rq_private_buf));
 
        /* Add request to the receive list */
-       list_add_tail(&req->rq_list, &xprt->recv);
+       list_add_tail(&req->rq_recv, &xprt->recv_queue);
        set_bit(RPC_TASK_NEED_RECV, &task->tk_runstate);
        spin_unlock(&xprt->queue_lock);
 
@@ -957,7 +957,7 @@ static void
 xprt_request_dequeue_receive_locked(struct rpc_task *task)
 {
        if (test_and_clear_bit(RPC_TASK_NEED_RECV, &task->tk_runstate))
-               list_del(&task->tk_rqstp->rq_list);
+               list_del(&task->tk_rqstp->rq_recv);
 }
 
 /**
@@ -1492,7 +1492,7 @@ static void xprt_init(struct rpc_xprt *xprt, struct net *net)
        spin_lock_init(&xprt->queue_lock);
 
        INIT_LIST_HEAD(&xprt->free);
-       INIT_LIST_HEAD(&xprt->recv);
+       INIT_LIST_HEAD(&xprt->recv_queue);
 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
        spin_lock_init(&xprt->bc_pa_lock);
        INIT_LIST_HEAD(&xprt->bc_pa_list);