Merge tag 'drm-next-2019-07-19' of git://anongit.freedesktop.org/drm/drm

[linux.git] / net / sunrpc / backchannel_rqst.c

diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index c47d82622fd12129048215190b19fcb82721f78f..339e8c077c2db9dadf79e6498b2361c483753be3 100644 (file)
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -31,25 +31,20 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #define RPCDBG_FACILITY        RPCDBG_TRANS
 #endif
 
+#define BC_MAX_SLOTS   64U
+
+unsigned int xprt_bc_max_slots(struct rpc_xprt *xprt)
+{
+       return BC_MAX_SLOTS;
+}
+
 /*
  * Helper routines that track the number of preallocation elements
  * on the transport.
  */
 static inline int xprt_need_to_requeue(struct rpc_xprt *xprt)
 {
-       return xprt->bc_alloc_count < atomic_read(&xprt->bc_free_slots);
-}
-
-static inline void xprt_inc_alloc_count(struct rpc_xprt *xprt, unsigned int n)
-{
-       atomic_add(n, &xprt->bc_free_slots);
-       xprt->bc_alloc_count += n;
-}
-
-static inline int xprt_dec_alloc_count(struct rpc_xprt *xprt, unsigned int n)
-{
-       atomic_sub(n, &xprt->bc_free_slots);
-       return xprt->bc_alloc_count -= n;
+       return xprt->bc_alloc_count < xprt->bc_alloc_max;
 }
 
 /*
@@ -145,6 +140,9 @@ int xprt_setup_bc(struct rpc_xprt *xprt, unsigned int min_reqs)
 
        dprintk("RPC:       setup backchannel transport\n");
 
+       if (min_reqs > BC_MAX_SLOTS)
+               min_reqs = BC_MAX_SLOTS;
+
        /*
         * We use a temporary list to keep track of the preallocated
         * buffers.  Once we're done building the list we splice it
@@ -172,7 +170,9 @@ int xprt_setup_bc(struct rpc_xprt *xprt, unsigned int min_reqs)
         */
        spin_lock(&xprt->bc_pa_lock);
        list_splice(&tmp_list, &xprt->bc_pa_list);
-       xprt_inc_alloc_count(xprt, min_reqs);
+       xprt->bc_alloc_count += min_reqs;
+       xprt->bc_alloc_max += min_reqs;
+       atomic_add(min_reqs, &xprt->bc_slot_count);
        spin_unlock(&xprt->bc_pa_lock);
 
        dprintk("RPC:       setup backchannel transport done\n");
@@ -220,11 +220,13 @@ void xprt_destroy_bc(struct rpc_xprt *xprt, unsigned int max_reqs)
                goto out;
 
        spin_lock_bh(&xprt->bc_pa_lock);
-       xprt_dec_alloc_count(xprt, max_reqs);
+       xprt->bc_alloc_max -= max_reqs;
        list_for_each_entry_safe(req, tmp, &xprt->bc_pa_list, rq_bc_pa_list) {
                dprintk("RPC:        req=%p\n", req);
                list_del(&req->rq_bc_pa_list);
                xprt_free_allocation(req);
+               xprt->bc_alloc_count--;
+               atomic_dec(&xprt->bc_slot_count);
                if (--max_reqs == 0)
                        break;
        }
@@ -241,13 +243,14 @@ static struct rpc_rqst *xprt_get_bc_request(struct rpc_xprt *xprt, __be32 xid,
        struct rpc_rqst *req = NULL;
 
        dprintk("RPC:       allocate a backchannel request\n");
-       if (atomic_read(&xprt->bc_free_slots) <= 0)
-               goto not_found;
        if (list_empty(&xprt->bc_pa_list)) {
                if (!new)
                        goto not_found;
+               if (atomic_read(&xprt->bc_slot_count) >= BC_MAX_SLOTS)
+                       goto not_found;
                list_add_tail(&new->rq_bc_pa_list, &xprt->bc_pa_list);
                xprt->bc_alloc_count++;
+               atomic_inc(&xprt->bc_slot_count);
        }
        req = list_first_entry(&xprt->bc_pa_list, struct rpc_rqst,
                                rq_bc_pa_list);
@@ -291,6 +294,7 @@ void xprt_free_bc_rqst(struct rpc_rqst *req)
        if (xprt_need_to_requeue(xprt)) {
                list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list);
                xprt->bc_alloc_count++;
+               atomic_inc(&xprt->bc_slot_count);
                req = NULL;
        }
        spin_unlock_bh(&xprt->bc_pa_lock);
@@ -357,7 +361,7 @@ void xprt_complete_bc_request(struct rpc_rqst *req, uint32_t copied)
 
        spin_lock(&xprt->bc_pa_lock);
        list_del(&req->rq_bc_pa_list);
-       xprt_dec_alloc_count(xprt, 1);
+       xprt->bc_alloc_count--;
        spin_unlock(&xprt->bc_pa_lock);
 
        req->rq_private_buf.len = copied;