Re: Need help debugging NFS issues new to 4.20 kernel

From: Chuck Lever <chuck.lever@oracle.com>
To: Trond Myklebust <trondmy@hammerspace.com>
Cc: "tibbs@math.uh.edu" <tibbs@math.uh.edu>,
	"bcodding@redhat.com" <bcodding@redhat.com>,
	Anna Schumaker <Anna.Schumaker@netapp.com>,
	Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: Need help debugging NFS issues new to 4.20 kernel
Date: Wed, 20 Feb 2019 10:39:16 -0500	[thread overview]
Message-ID: <1FA7F8B3-872E-4AF6-8125-2664443E59D1@oracle.com> (raw)
In-Reply-To: <2ab06cbdc19d7a642e04f1e66abbeaa507b034bc.camel@hammerspace.com>

> On Feb 20, 2019, at 10:37 AM, Trond Myklebust <trondmy@hammerspace.com> wrote:
> 
> On Wed, 2019-02-20 at 09:25 -0600, Jason L Tibbitts III wrote:
>> Sadly, after a bit more testing I find that 4.20.10 with that patch
>> applied still exhibits the problem.  Just found a machine where NFS
>> hung
>> up just six minutes after the user logged in.  As always: nothing is
>> logged to the client or the server.  I turned on the tracing as
>> requested previously and see what I think it just the same sequence
>> as
>> before.  Please let me know if there is any other information I can
>> provide.  Right now I'm going to build 4.20.10 with my previously
>> posted
>> revert patch applied and roll that out to the same 50 hosts and see
>> how
>> it fares.
>> 
>> - J<
>> 
>>    kworker/u8:0-12608 [001] .... 47884.661073: rpc_request: task:
>> 20469@1 nfsv4 SEQUENCE (async)
>>    kworker/u8:0-12608 [001] .... 47884.661073: rpc_task_run_action:
>> task:20469@1 flags=5281 state=0005 status=0 action=call_reserve
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661074: rpc_task_run_action:
>> task:20469@1 flags=5281 state=0005 status=0 action=call_reserveresult
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661074: rpc_task_run_action:
>> task:20469@1 flags=5281 state=0005 status=0 action=call_refresh
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661075: rpc_task_run_action:
>> task:20469@1 flags=5281 state=0005 status=0 action=call_refreshresult
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661076: rpc_task_run_action:
>> task:20469@1 flags=5281 state=0005 status=0 action=call_allocate
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661076: rpc_task_run_action:
>> task:20469@1 flags=5281 state=0005 status=0 action=call_encode
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661091: rpc_task_run_action:
>> task:20469@1 flags=5281 state=001d status=0 action=call_bind [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661091: rpc_task_run_action:
>> task:20469@1 flags=5281 state=001d status=0 action=call_connect
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661092: rpc_task_run_action:
>> task:20469@1 flags=5281 state=001d status=0 action=call_transmit
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661106: xprt_transmit:
>> peer=[172.21.86.74]:2049 xid=0x0d7ca068 status=0
>>    kworker/u8:0-12608 [001] .... 47884.661107: rpc_task_run_action:
>> task:20469@1 flags=5a81 state=0015 status=0
>> action=call_transmit_status [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661107: rpc_task_sleep: task:
>> 20469@1 flags=5a81 state=0015 status=0 timeout=60000
>> queue=xprt_pending
>>    kworker/u9:0-12884 [002] .... 47884.661371: xprt_lookup_rqst:
>> peer=[172.21.86.74]:2049 xid=0x0d7ca068 status=0
>>    kworker/u9:0-12884 [002] .... 47884.661372: xprt_complete_rqst:
>> peer=[172.21.86.74]:2049 xid=0x0d7ca068 status=112
>>    kworker/u9:0-12884 [002] .... 47884.661373: rpc_task_wakeup:
>> task:20469@1 flags=5a81 state=0006 status=0 timeout=60000
>> queue=xprt_pending
>>    kworker/u9:0-12884 [002] .... 47884.661375:
>> xs_stream_read_request: peer=[172.21.86.74]:2049 xid=0x0d7ca068
>> copied=112 reclen=112 offset=112
>>    kworker/u9:0-12884 [002] .... 47884.661376: xs_stream_read_data:
>> peer=[172.21.86.74]:2049 err=-11 total=116
>>    kworker/u8:0-12608 [001] .... 47884.661388: rpc_task_run_action:
>> task:20469@1 flags=5a81 state=0005 status=0 action=xprt_timer
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661389: rpc_task_run_action:
>> task:20469@1 flags=5a81 state=0005 status=0 action=call_status
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661389: rpc_task_run_action:
>> task:20469@1 flags=5a81 state=0005 status=0 action=call_decode
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661408: rpc_task_run_action:
>> task:20469@1 flags=5a81 state=0005 status=-10063 action=rpc_exit_task
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661409: nfs4_sequence_done:
>> error=-10063 (SEQ_MISORDERED) session=0x4480e725 slot_nr=0 seq_nr=1
>> highest_slotid=0 target_highest_slotid=0 status_flags=0 ()
>>    kworker/u8:0-12608 [001] .... 47884.661410: rpc_stats_latency:
>> task:20469@1 xid=0x0d7ca068 nfsv4 SEQUENCE backlog=21 rtt=278
>> execute=339
>>    kworker/u8:0-12608 [001] .... 47884.661412: rpc_task_run_action:
>> task:20469@1 flags=5281 state=0005 status=0 action=rpc_prepare_task
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661413: nfs4_setup_sequence:
>> session=0x4480e725 slot_nr=0 seq_nr=1 highest_used_slotid=0
>>    kworker/u8:0-12608 [001] .... 47884.661413: rpc_task_run_action:
>> task:20469@1 flags=5281 state=0005 status=0 action=call_start
>> [sunrpc]
>>    kworker/u8:0-12608 [001] .... 47884.661414: rpc_request: task:
>> 20469@1 nfsv4 SEQUENCE (async)
> 
> This is not an RPC layer issue. It is a SEQ_MISORDERED error on slot 0.
> If the client can't recover then that will hang your NFSv4.1 session
> against that server.
> 
> Are you sure this isn't what was happening previously?

This is exactly what was happening earlier. See my e-mail to the list
on Feb 8.

--
Chuck Lever