xprtrdma: Properly handle RDMA_ERROR replies

These are shorter than RPCRDMA_HDRLEN_MIN, and they need to
complete the waiting RPC.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/include/linux/sunrpc/rpc_rdma.h b/include/linux/sunrpc/rpc_rdma.h
index 8c6d23c..3b1ff38 100644 (file)
--- a/include/linux/sunrpc/rpc_rdma.h
+++ b/include/linux/sunrpc/rpc_rdma.h
@@ -93,6 +93,12 @@ struct rpcrdma_msg {
                        __be32 rm_pempty[3];    /* 3 empty chunk lists */
                } rm_padded;
 
+               struct {
+                       __be32 rm_err;
+                       __be32 rm_vers_low;
+                       __be32 rm_vers_high;
+               } rm_error;
+
                __be32 rm_chunks[0];    /* read, write and reply chunks */
 
        } rm_body;
@@ -109,11 +115,6 @@ enum rpcrdma_errcode {
        ERR_CHUNK = 2
 };
 
-struct rpcrdma_err_vers {
-       uint32_t rdma_vers_low; /* Version range supported by peer */
-       uint32_t rdma_vers_high;
-};
-
 enum rpcrdma_proc {
        RDMA_MSG = 0,           /* An RPC call or reply msg */
        RDMA_NOMSG = 1,         /* An RPC call or reply msg - separate body */

diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 0607391..35f8108 100644 (file)
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -795,7 +795,7 @@ rpcrdma_reply_handler(struct rpcrdma_rep *rep)
        struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
        struct rpc_xprt *xprt = &r_xprt->rx_xprt;
        __be32 *iptr;
-       int rdmalen, status;
+       int rdmalen, status, rmerr;
        unsigned long cwnd;
        u32 credits;
 
@@ -803,12 +803,10 @@ rpcrdma_reply_handler(struct rpcrdma_rep *rep)
 
        if (rep->rr_len == RPCRDMA_BAD_LEN)
                goto out_badstatus;
-       if (rep->rr_len < RPCRDMA_HDRLEN_MIN)
+       if (rep->rr_len < RPCRDMA_HDRLEN_ERR)
                goto out_shortreply;
 
        headerp = rdmab_to_msg(rep->rr_rdmabuf);
-       if (headerp->rm_vers != rpcrdma_version)
-               goto out_badversion;
 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
        if (rpcrdma_is_bcall(headerp))
                goto out_bcall;
@@ -838,6 +836,9 @@ rpcrdma_reply_handler(struct rpcrdma_rep *rep)
        req->rl_reply = rep;
        xprt->reestablish_timeout = 0;
 
+       if (headerp->rm_vers != rpcrdma_version)
+               goto out_badversion;
+
        /* check for expected message types */
        /* The order of some of these tests is important. */
        switch (headerp->rm_type) {
@@ -898,6 +899,9 @@ rpcrdma_reply_handler(struct rpcrdma_rep *rep)
                status = rdmalen;
                break;
 
+       case rdma_error:
+               goto out_rdmaerr;
+
 badheader:
        default:
                dprintk("%s: invalid rpcrdma reply header (type %d):"
@@ -913,6 +917,7 @@ badheader:
                break;
        }
 
+out:
        /* Invalidate and flush the data payloads before waking the
         * waiting application. This guarantees the memory region is
         * properly fenced from the server before the application
@@ -955,13 +960,43 @@ out_bcall:
        return;
 #endif
 
-out_shortreply:
-       dprintk("RPC:       %s: short/invalid reply\n", __func__);
-       goto repost;
-
+/* If the incoming reply terminated a pending RPC, the next
+ * RPC call will post a replacement receive buffer as it is
+ * being marshaled.
+ */
 out_badversion:
        dprintk("RPC:       %s: invalid version %d\n",
                __func__, be32_to_cpu(headerp->rm_vers));
+       status = -EIO;
+       r_xprt->rx_stats.bad_reply_count++;
+       goto out;
+
+out_rdmaerr:
+       rmerr = be32_to_cpu(headerp->rm_body.rm_error.rm_err);
+       switch (rmerr) {
+       case ERR_VERS:
+               pr_err("%s: server reports header version error (%u-%u)\n",
+                      __func__,
+                      be32_to_cpu(headerp->rm_body.rm_error.rm_vers_low),
+                      be32_to_cpu(headerp->rm_body.rm_error.rm_vers_high));
+               break;
+       case ERR_CHUNK:
+               pr_err("%s: server reports header decoding error\n",
+                      __func__);
+               break;
+       default:
+               pr_err("%s: server reports unknown error %d\n",
+                      __func__, rmerr);
+       }
+       status = -EREMOTEIO;
+       r_xprt->rx_stats.bad_reply_count++;
+       goto out;
+
+/* If no pending RPC transaction was matched, post a replacement
+ * receive buffer before returning.
+ */
+out_shortreply:
+       dprintk("RPC:       %s: short/invalid reply\n", __func__);
        goto repost;
 
 out_nomatch: