Hi Chuk and Trond I will resend a v2 for this. What if ib_post_send() fails with immidate error, I that case also DECR_CQCOUNT() will be called but no completion will be reported. Will that not cause any problems? Also in rpcrdma_register_frmr_external() I am seeing DECT_CQCOUNT is called twice First at line 1538 (unlikely however) and second at line 1562. Shouldn't it be only at 1562? -----Original Message----- From: Chuck Lever [mailto:chuck.lever@xxxxxxxxxx] Sent: Thursday, April 10, 2014 1:57 AM To: Devesh Sharma Cc: Linux NFS Mailing List; linux-rdma@xxxxxxxxxxxxxxx; Trond Myklebust Subject: Re: [PATCH V1] NFS-RDMA: fix qp pointer validation checks On Apr 9, 2014, at 4:22 PM, Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> wrote: > Hi Devesh, > > This looks a lot better. I still have a couple of small suggestions, though. > > On Apr 9, 2014, at 14:40, Devesh Sharma <devesh.sharma@xxxxxxxxxx> wrote: > >> If the rdma_create_qp fails to create qp due to device firmware being >> in invalid state xprtrdma still tries to destroy the non-existant qp >> and ends up in a NULL pointer reference crash. >> Adding proper checks for vaidating QP pointer avoids this to happen. >> >> Signed-off-by: Devesh Sharma <devesh.sharma@xxxxxxxxxx> >> --- >> net/sunrpc/xprtrdma/verbs.c | 29 +++++++++++++++++++++++++---- >> 1 files changed, 25 insertions(+), 4 deletions(-) >> >> diff --git a/net/sunrpc/xprtrdma/verbs.c >> b/net/sunrpc/xprtrdma/verbs.c index 9372656..902ac78 100644 >> --- a/net/sunrpc/xprtrdma/verbs.c >> +++ b/net/sunrpc/xprtrdma/verbs.c >> @@ -831,10 +831,12 @@ rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia) >> if (ep->rep_connected != 0) { >> struct rpcrdma_xprt *xprt; >> retry: >> - rc = rpcrdma_ep_disconnect(ep, ia); >> - if (rc && rc != -ENOTCONN) >> - dprintk("RPC: %s: rpcrdma_ep_disconnect" >> + if (ia->ri_id->qp) { >> + rc = rpcrdma_ep_disconnect(ep, ia); >> + if (rc && rc != -ENOTCONN) >> + dprintk("RPC: %s: rpcrdma_ep_disconnect" >> " status %i\n", __func__, rc); >> + } >> rpcrdma_clean_cq(ep->rep_cq); >> >> xprt = container_of(ia, struct rpcrdma_xprt, rx_ia); @@ -859,7 >> +861,9 @@ retry: >> goto out; >> } >> /* END TEMP */ >> - rdma_destroy_qp(ia->ri_id); >> + if (ia->ri_id->qp) { >> + rdma_destroy_qp(ia->ri_id); >> + } > > Nit: No need for braces here. > >> rdma_destroy_id(ia->ri_id); >> ia->ri_id = id; >> } >> @@ -1557,6 +1561,13 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg, >> frmr_wr.wr.fast_reg.rkey = seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey; >> DECR_CQCOUNT(&r_xprt->rx_ep); I don't think you can DECR_CQCOUNT, then exit without posting the send. That will screw up the completion counter and result in a transport hang, won't it? >> >> + if (!ia->ri_is->qp) { >> + rc = -EINVAL; >> + while (i--) >> + rpcrdma_unmap_one(ia, --seg); >> + goto out; >> + } > > Instead of duplicating the rpcrdma_unmap_one() cleanup here, why not > just do > > if (ia->ri_is->qp) > rc = ib_post_send(...) > else > rc = -EINVAL; > > BTW: can we not simply test for ia->ri_is->qp before we even call rpcrdma_map_one() and hence bail out before we have to do any cleanup? > >> + >> rc = ib_post_send(ia->ri_id->qp, post_wr, &bad_wr); >> >> if (rc) { >> @@ -1571,6 +1582,7 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg, >> seg1->mr_len = len; >> } >> *nsegs = i; >> +out: >> return rc; >> } >> >> @@ -1592,6 +1604,9 @@ rpcrdma_deregister_frmr_external(struct rpcrdma_mr_seg *seg, >> invalidate_wr.ex.invalidate_rkey = seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey; >> DECR_CQCOUNT(&r_xprt->rx_ep); Ditto. >> >> + if (!ia->ri_id->qp) >> + return -EINVAL; >> + >> rc = ib_post_send(ia->ri_id->qp, &invalidate_wr, &bad_wr); >> if (rc) >> dprintk("RPC: %s: failed ib_post_send for invalidate," >> @@ -1923,6 +1938,9 @@ rpcrdma_ep_post(struct rpcrdma_ia *ia, >> send_wr.send_flags = IB_SEND_SIGNALED; >> } Ditto. >> >> + if (!ia->ri_id->qp) >> + return -EINVAL; >> + >> rc = ib_post_send(ia->ri_id->qp, &send_wr, &send_wr_fail); >> if (rc) >> dprintk("RPC: %s: ib_post_send returned %i\n", __func__, >> @@ -1951,6 +1969,9 @@ rpcrdma_ep_post_recv(struct rpcrdma_ia *ia, >> rep->rr_iov.addr, rep->rr_iov.length, DMA_BIDIRECTIONAL); >> >> DECR_CQCOUNT(ep); And here. >> + >> + if (!ia->ri_id->qp) >> + return -EINVAL; >> rc = ib_post_recv(ia->ri_id->qp, &recv_wr, &recv_wr_fail); >> >> if (rc) >> -- >> 1.7.1 >> > > _________________________________ > Trond Myklebust > Linux NFS client maintainer, PrimaryData > trond.myklebust@xxxxxxxxxxxxxxx > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" > in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo > info at http://vger.kernel.org/majordomo-info.html -- Chuck Lever chuck[dot]lever[at]oracle[dot]com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
