Merge tag 'nfsd-4.21' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Thanks to Vasily Averin for fixing a use-after-free in the
  containerized NFSv4.2 client, and cleaning up some convoluted
  backchannel server code in the process.

  Otherwise, miscellaneous smaller bugfixes and cleanup"

* tag 'nfsd-4.21' of git://linux-nfs.org/~bfields/linux: (25 commits)
  nfs: fixed broken compilation in nfs_callback_up_net()
  nfs: minor typo in nfs4_callback_up_net()
  sunrpc: fix debug message in svc_create_xprt()
  sunrpc: make visible processing error in bc_svc_process()
  sunrpc: remove unused xpo_prep_reply_hdr callback
  sunrpc: remove svc_rdma_bc_class
  sunrpc: remove svc_tcp_bc_class
  sunrpc: remove unused bc_up operation from rpc_xprt_ops
  sunrpc: replace svc_serv->sv_bc_xprt by boolean flag
  sunrpc: use-after-free in svc_process_common()
  sunrpc: use SVC_NET() in svcauth_gss_* functions
  nfsd: drop useless LIST_HEAD
  lockd: Show pid of lockd for remote locks
  NFSD remove OP_CACHEME from 4.2 op_flags
  nfsd: Return EPERM, not EACCES, in some SETATTR cases
  sunrpc: fix cache_head leak due to queued request
  nfsd: clean up indentation, increase indentation in switch statement
  svcrdma: Optimize the logic that selects the R_key to invalidate
  nfsd: fix a warning in __cld_pipe_upcall()
  nfsd4: fix crash on writing v4_end_grace before nfsd startup
  ...

1 files changed, 63 insertions, 0 deletions

diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index b24d5b8f2fee..828b149eaaef 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -485,6 +485,68 @@ static __be32 *xdr_check_reply_chunk(__be32 *p, const __be32 *end)
 	return p;
 }
 
+/* RPC-over-RDMA Version One private extension: Remote Invalidation.
+ * Responder's choice: requester signals it can handle Send With
+ * Invalidate, and responder chooses one R_key to invalidate.
+ *
+ * If there is exactly one distinct R_key in the received transport
+ * header, set rc_inv_rkey to that R_key. Otherwise, set it to zero.
+ *
+ * Perform this operation while the received transport header is
+ * still in the CPU cache.
+ */
+static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma,
+				  struct svc_rdma_recv_ctxt *ctxt)
+{
+	__be32 inv_rkey, *p;
+	u32 i, segcount;
+
+	ctxt->rc_inv_rkey = 0;
+
+	if (!rdma->sc_snd_w_inv)
+		return;
+
+	inv_rkey = xdr_zero;
+	p = ctxt->rc_recv_buf;
+	p += rpcrdma_fixed_maxsz;
+
+	/* Read list */
+	while (*p++ != xdr_zero) {
+		p++;	/* position */
+		if (inv_rkey == xdr_zero)
+			inv_rkey = *p;
+		else if (inv_rkey != *p)
+			return;
+		p += 4;
+	}
+
+	/* Write list */
+	while (*p++ != xdr_zero) {
+		segcount = be32_to_cpup(p++);
+		for (i = 0; i < segcount; i++) {
+			if (inv_rkey == xdr_zero)
+				inv_rkey = *p;
+			else if (inv_rkey != *p)
+				return;
+			p += 4;
+		}
+	}
+
+	/* Reply chunk */
+	if (*p++ != xdr_zero) {
+		segcount = be32_to_cpup(p++);
+		for (i = 0; i < segcount; i++) {
+			if (inv_rkey == xdr_zero)
+				inv_rkey = *p;
+			else if (inv_rkey != *p)
+				return;
+			p += 4;
+		}
+	}
+
+	ctxt->rc_inv_rkey = be32_to_cpu(inv_rkey);
+}
+
 /* On entry, xdr->head[0].iov_base points to first byte in the
  * RPC-over-RDMA header.
  *
@@ -746,6 +808,7 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
 		svc_rdma_recv_ctxt_put(rdma_xprt, ctxt);
 		return ret;
 	}
+	svc_rdma_get_inv_rkey(rdma_xprt, ctxt);
 
 	p += rpcrdma_fixed_maxsz;
 	if (*p != xdr_zero)