Merge tag 'nfs-for-5.4-2' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client bugfixes from Anna Schumaker:
 "Stable bugfixes:
   - Fix O_DIRECT accounting of number of bytes read/written # v4.1+

  Other fixes:
   - Fix nfsi->nrequests count error on nfs_inode_remove_request()
   - Remove redundant mirror tracking in O_DIRECT
   - Fix leak of clp->cl_acceptor string
   - Fix race to sk_err after xs_error_report"

* tag 'nfs-for-5.4-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  SUNRPC: fix race to sk_err after xs_error_report
  NFSv4: Fix leak of clp->cl_acceptor string
  NFS: Remove redundant mirror tracking in O_DIRECT
  NFS: Fix O_DIRECT accounting of number of bytes read/written
  nfs: Fix nfsi->nrequests count error on nfs_inode_remove_request

1 files changed, 8 insertions, 9 deletions

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 9ac88722fa83..70e52f567b2a 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1249,19 +1249,21 @@ static void xs_error_report(struct sock *sk)
 {
         struct sock_xprt *transport;
         struct rpc_xprt *xprt;
-        int err;
 
         read_lock_bh(&sk->sk_callback_lock);
         if (!(xprt = xprt_from_sock(sk)))
                 goto out;
 
         transport = container_of(xprt, struct sock_xprt, xprt);
-        err = -sk->sk_err;
-        if (err == 0)
+        transport->xprt_err = -sk->sk_err;
+        if (transport->xprt_err == 0)
                 goto out;
         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
-                        xprt, -err);
-        trace_rpc_socket_error(xprt, sk->sk_socket, err);
+                        xprt, -transport->xprt_err);
+        trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
+
+        /* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
+        smp_mb__before_atomic();
         xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
  out:
         read_unlock_bh(&sk->sk_callback_lock);
@@ -2476,7 +2478,6 @@ static void xs_wake_write(struct sock_xprt *transport)
 static void xs_wake_error(struct sock_xprt *transport)
 {
         int sockerr;
-        int sockerr_len = sizeof(sockerr);
 
         if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
                 return;
@@ -2485,9 +2486,7 @@ static void xs_wake_error(struct sock_xprt *transport)
                 goto out;
         if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
                 goto out;
-        if (kernel_getsockopt(transport->sock, SOL_SOCKET, SO_ERROR,
-                                (char *)&sockerr, &sockerr_len) != 0)
-                goto out;
+        sockerr = xchg(&transport->xprt_err, 0);
         if (sockerr < 0)
                 xprt_wake_pending_tasks(&transport->xprt, sockerr);
 out: