xprtrdma: Don't post a LOCAL_INV in rpcrdma_register_frmr_external()

Any FRMR arriving in rpcrdma_register_frmr_external() is now
guaranteed to be either invalid, or to be targeted by a queued
LOCAL_INV that will invalidate it before the adapter processes
the FAST_REG_MR being built here.

The problem with current arrangement of chaining a LOCAL_INV to the
FAST_REG_MR is that if the transport is not connected, the LOCAL_INV
is flushed and the FAST_REG_MR is flushed. This leaves the FRMR
valid with the old rkey. But rpcrdma_register_frmr_external() has
already bumped the in-memory rkey.

Next time through rpcrdma_register_frmr_external(), a LOCAL_INV and
FAST_REG_MR is attempted again because the FRMR is still valid. But
the rkey no longer matches the hardware's rkey, and a memory
management operation error occurs.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index ca55acf423650e2338c4ce1773620704c12b21df..7459b867d7d6b81bb6f518f7ee8a1fcdaf7aaf0a 100644 (file)
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1695,8 +1695,7 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
        struct rpcrdma_mw *mw = seg1->mr_chunk.rl_mw;
        struct rpcrdma_frmr *frmr = &mw->r.frmr;
        struct ib_mr *mr = frmr->fr_mr;
-       struct ib_send_wr invalidate_wr, frmr_wr, *bad_wr, *post_wr;
-
+       struct ib_send_wr frmr_wr, *bad_wr;
        u8 key;
        int len, pageoff;
        int i, rc;
@@ -1728,22 +1727,6 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
        dprintk("RPC:       %s: Using frmr %p to map %d segments\n",
                __func__, mw, i);
 
-       if (unlikely(frmr->fr_state != FRMR_IS_INVALID)) {
-               dprintk("RPC:       %s: frmr %x left valid, posting invalidate.\n",
-                       __func__, mr->rkey);
-               /* Invalidate before using. */
-               memset(&invalidate_wr, 0, sizeof invalidate_wr);
-               invalidate_wr.wr_id = (unsigned long)(void *)mw;
-               invalidate_wr.next = &frmr_wr;
-               invalidate_wr.opcode = IB_WR_LOCAL_INV;
-               invalidate_wr.send_flags = IB_SEND_SIGNALED;
-               invalidate_wr.ex.invalidate_rkey = mr->rkey;
-               DECR_CQCOUNT(&r_xprt->rx_ep);
-               post_wr = &invalidate_wr;
-       } else
-               post_wr = &frmr_wr;
-
-       /* Prepare FRMR WR */
        memset(&frmr_wr, 0, sizeof frmr_wr);
        frmr_wr.wr_id = (unsigned long)(void *)mw;
        frmr_wr.opcode = IB_WR_FAST_REG_MR;
@@ -1768,8 +1751,7 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
        frmr_wr.wr.fast_reg.rkey = mr->rkey;
        DECR_CQCOUNT(&r_xprt->rx_ep);
 
-       rc = ib_post_send(ia->ri_id->qp, post_wr, &bad_wr);
-
+       rc = ib_post_send(ia->ri_id->qp, &frmr_wr, &bad_wr);
        if (rc) {
                dprintk("RPC:       %s: failed ib_post_send for register,"
                        " status %i\n", __func__, rc);