Merge tag 'nfs-for-4.20-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - Fix the NFSv4.1 r/wsize sanity checking
   - Reset the RPC/RDMA credit grant properly after a disconnect
   - Fix a missed page unlock after pg_doio()

  Features and optimisations:
   - Overhaul of the RPC client socket code to eliminate a locking
     bottleneck and reduce the latency when transmitting lots of
     requests in parallel.
   - Allow parallelisation of the RPCSEC_GSS encoding of an RPC request.
   - Convert the RPC client socket receive code to use iovec_iter() for
     improved efficiency.
   - Convert several NFS and RPC lookup operations to use RCU instead of
     taking global locks.
   - Avoid the need for BH-safe locks in the RPC/RDMA back channel.

  Bugfixes and cleanups:
   - Fix lock recovery during NFSv4 delegation recalls
   - Fix the NFSv4 + NFSv4.1 "lookup revalidate + open file" case.
   - Fixes for the RPC connection metrics
   - Various RPC client layer cleanups to consolidate stream based
     sockets
   - RPC/RDMA connection cleanups
   - Simplify the RPC/RDMA cleanup after memory operation failures
   - Clean ups for NFS v4.2 copy completion and NFSv4 open state
     reclaim"

* tag 'nfs-for-4.20-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (97 commits)
  SUNRPC: Convert the auth cred cache to use refcount_t
  SUNRPC: Convert auth creds to use refcount_t
  SUNRPC: Simplify lookup code
  SUNRPC: Clean up the AUTH cache code
  NFS: change sign of nfs_fh length
  sunrpc: safely reallow resvport min/max inversion
  nfs: remove redundant call to nfs_context_set_write_error()
  nfs: Fix a missed page unlock after pg_doio()
  SUNRPC: Fix a compile warning for cmpxchg64()
  NFSv4.x: fix lock recovery during delegation recall
  SUNRPC: use cmpxchg64() in gss_seq_send64_fetch_and_inc()
  xprtrdma: Squelch a sparse warning
  xprtrdma: Clean up xprt_rdma_disconnect_inject
  xprtrdma: Add documenting comments
  xprtrdma: Report when there were zero posted Receives
  xprtrdma: Move rb_flags initialization
  xprtrdma: Don't disable BH's in backchannel server
  xprtrdma: Remove memory address of "ep" from an error message
  xprtrdma: Rename rpcrdma_qp_async_error_upcall
  xprtrdma: Simplify RPC wake-ups on connect
  ...

1 files changed, 11 insertions, 9 deletions

diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c
index 90adeff4c06b..e5b367a3e517 100644
--- a/net/sunrpc/xprtrdma/backchannel.c
+++ b/net/sunrpc/xprtrdma/backchannel.c
@@ -51,12 +51,11 @@ static int rpcrdma_bc_setup_reqs(struct rpcrdma_xprt *r_xprt,
 		rqst = &req->rl_slot;
 
 		rqst->rq_xprt = xprt;
-		INIT_LIST_HEAD(&rqst->rq_list);
 		INIT_LIST_HEAD(&rqst->rq_bc_list);
 		__set_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state);
-		spin_lock_bh(&xprt->bc_pa_lock);
+		spin_lock(&xprt->bc_pa_lock);
 		list_add(&rqst->rq_bc_pa_list, &xprt->bc_pa_list);
-		spin_unlock_bh(&xprt->bc_pa_lock);
+		spin_unlock(&xprt->bc_pa_lock);
 
 		size = r_xprt->rx_data.inline_rsize;
 		rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, GFP_KERNEL);
@@ -201,6 +200,9 @@ int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst)
 	if (!xprt_connected(rqst->rq_xprt))
 		goto drop_connection;
 
+	if (!xprt_request_get_cong(rqst->rq_xprt, rqst))
+		return -EBADSLT;
+
 	rc = rpcrdma_bc_marshal_reply(rqst);
 	if (rc < 0)
 		goto failed_marshal;
@@ -228,16 +230,16 @@ void xprt_rdma_bc_destroy(struct rpc_xprt *xprt, unsigned int reqs)
 	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 	struct rpc_rqst *rqst, *tmp;
 
-	spin_lock_bh(&xprt->bc_pa_lock);
+	spin_lock(&xprt->bc_pa_lock);
 	list_for_each_entry_safe(rqst, tmp, &xprt->bc_pa_list, rq_bc_pa_list) {
 		list_del(&rqst->rq_bc_pa_list);
-		spin_unlock_bh(&xprt->bc_pa_lock);
+		spin_unlock(&xprt->bc_pa_lock);
 
 		rpcrdma_bc_free_rqst(r_xprt, rqst);
 
-		spin_lock_bh(&xprt->bc_pa_lock);
+		spin_lock(&xprt->bc_pa_lock);
 	}
-	spin_unlock_bh(&xprt->bc_pa_lock);
+	spin_unlock(&xprt->bc_pa_lock);
 }
 
 /**
@@ -255,9 +257,9 @@ void xprt_rdma_bc_free_rqst(struct rpc_rqst *rqst)
 	rpcrdma_recv_buffer_put(req->rl_reply);
 	req->rl_reply = NULL;
 
-	spin_lock_bh(&xprt->bc_pa_lock);
+	spin_lock(&xprt->bc_pa_lock);
 	list_add_tail(&rqst->rq_bc_pa_list, &xprt->bc_pa_list);
-	spin_unlock_bh(&xprt->bc_pa_lock);
+	spin_unlock(&xprt->bc_pa_lock);
 }
 
 /**