On Mar 28, 2014, at 4:06 PM, sagi grimberg <sagig@xxxxxxxxxxxx> wrote: > On 3/29/2014 1:30 AM, Chuck Lever wrote: >> On Mar 28, 2014, at 2:42 AM, Senn Klemens <klemens.senn@xxxxxxxxx> wrote: >> >>> Hi Chuck, >>> >>> On 03/27/2014 04:59 PM, Chuck Lever wrote: >>>> Hi- >>>> >>>> >>>> On Mar 27, 2014, at 12:53 AM, Reiter Rafael <rafael.reiter@xxxxxxxxx> wrote: >>>> >>>>> On 03/26/2014 07:15 PM, Chuck Lever wrote: >>>>>> Hi Rafael- >>>>>> >>>>>> I’ll take a look. Can you report your HCA and how you reproduce this issue? >>>>> The HCA is Mellanox Technologies MT26428. >>>>> >>>>> Reproduction: >>>>> 1) Mount a directory via NFS/RDMA >>>>> mount -t nfs -o port=20049,rdma,vers=4.0,timeo=900 172.16.100.2:/ /mnt/ >>> An additional "ls /mnt" is needed here (between step 1 and 2) >>> >>>>> 2) Pull the Infiniband cable or use ibportstate to disrupt the Infiniband connection >>>>> 3) ls /mnt >>>>> 4) wait 5-30 seconds >>>> Thanks for the information. >>>> >>>> I have that HCA, but I won’t have access to my test systems for a week (traveling). So can you try this: >>>> >>>> # rpcdebug -m rpc -s trans >>>> >>>> then reproduce (starting with step 1 above). Some debugging output will appear at the tail of /var/log/messages. Copy it to this thread. >>>> >>> The output of /var/log/messages is: >>> >>> [ 143.233701] RPC: 1688 xprt_rdma_allocate: size 1112 too large for >>> buffer[1024]: prog 100003 vers 4 proc 1 >>> [ 143.233708] RPC: 1688 xprt_rdma_allocate: size 1112, request >>> 0xffff88105894c000 >>> [ 143.233715] RPC: 1688 rpcrdma_inline_pullup: pad 0 destp >>> 0xffff88105894d7dc len 124 hdrlen 124 >>> [ 143.233718] RPC: rpcrdma_register_frmr_external: Using frmr >>> ffff88084e589260 to map 1 segments >>> [ 143.233722] RPC: 1688 rpcrdma_create_chunks: reply chunk elem >>> 652@0x105894d92c:0xced01 (last) >>> [ 143.233725] RPC: 1688 rpcrdma_marshal_req: reply chunk: hdrlen 48 >>> rpclen 124 padlen 0 headerp 0xffff88105894d100 base 0xffff88105894d760 >>> lkey 0x8000 >>> [ 143.233785] RPC: rpcrdma_event_process: event rep >>> ffff88084e589260 status 0 opcode 8 length 0 >>> [ 177.272397] RPC: rpcrdma_event_process: event rep >>> (null) status C opcode FFFF8808 length 4294967295 >>> [ 177.272649] RPC: rpcrdma_event_process: event rep >>> ffff880848ed0000 status 5 opcode FFFF8808 length 4294936584 >> The mlx4 provider is returning a WC completion status of >> IB_WC_WR_FLUSH_ERR. >> >>> [ 177.272651] RPC: rpcrdma_event_process: WC opcode -30712 status >>> 5, connection lost >> -30712 is a bogus WC opcode. So the mlx4 provider is not filling in the >> WC opcode. rpcrdma_event_process() thus can’t depend on the contents of >> the ib_wc.opcode field when the WC completion status != IB_WC_SUCCESS. > > Hey Chuck, > > That is correct, the opcode field in the wc is not reliable in FLUSH errors. > >> >> A copy of the opcode reachable from the incoming rpcrdma_rep could be >> added, initialized in the forward paths. rpcrdma_event_process() could >> use the copy in the error case. > > How about suppressing completions alltogether for fast_reg and local_inv work requests? > if these shall fail you will get an error completion and the QP will transition to error state > generating FLUSH_ERR completions for all pending WRs. In this case, you can just ignore > flush fast_reg + local_inv errors. > > see http://marc.info/?l=linux-rdma&m=139047309831997&w=2 While considering your suggestion, I see that my proposed fix doesn’t work. In the FAST_REG_MR and LOCAL_INV cases, wr_id points to a struct rpcrdma_mw, not a struct rpcrdma_rep. Putting a copy of the opcode in rpcrdma_rep would have no effect. Worse: > 158 if (IB_WC_SUCCESS != wc->status) { > 159 dprintk("RPC: %s: WC opcode %d status %X, connection lost\n", > 160 __func__, wc->opcode, wc->status); > 161 rep->rr_len = ~0U; Suppose this is an IB_WC_FAST_REG_MR completion, so “rep” here is actually a struct rpcrdma_mw, not a struct rpcrdma_rep. Line 161 pokes 32 one-bits at the top of that struct rpcrdma_mw. If wc->opcode was always usable, we’d at least have to fix that. > 162 if (wc->opcode != IB_WC_FAST_REG_MR && wc->opcode != IB_WC_LOCAL_INV) > 163 rpcrdma_schedule_tasklet(rep); > 164 return; > 165 } > 166 > 167 switch (wc->opcode) { > 168 case IB_WC_FAST_REG_MR: > 169 frmr = (struct rpcrdma_mw *)(unsigned long)wc->wr_id; > 170 frmr->r.frmr.state = FRMR_IS_VALID; > 171 break; To make my initial solution work, you’d have to add a field to both struct rpcrdma_mw and struct rpcrdma_rep, and ensure they are at the same offset in both structures. Ewe. Eliminating completions for FAST_REG_MR and LOCAL_INV might be a preferable way to address this. -- 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
