Re: NFSD server is constantly returning nfserr_bad_stateid on 3.2 kernel

["J. Bruce Fields" <bfields@fieldses.org>]

On Tue, Aug 13, 2013 at 12:48:01PM +0530, Shyam Kaushik wrote:
> Hi Bruce,
> 
> I managed to nail this issue down. We have a flaw in IDR that it wraps
> around at 2^30. See this chain for more on it
> http://comments.gmane.org/gmane.linux.kernel/1543273

Looks like this got fixed by the recent IDR rewrite?

--b.

> Unfortunately NFSD wraps around at MAX_INT which is currently flawed.
> 
> I added debug within NFSD as you suggested & here are the snippets
> 
> NFS client came & did an open of file
> Aug 12 11:21:34 srv1 kernel: [377723.629810] nfsv4 compound op #2/5:
> 18 (OP_OPEN)
> Aug 12 11:21:34 srv1 kernel: [377723.629812] NFSD: nfsd4_open filename
> exports op_openowner           (null)
> Aug 12 11:21:34 srv1 kernel: [377723.629816] [6809] renewing client
> (clientid 5208f000/000013bf)
> Aug 12 11:21:34 srv1 kernel: [377723.629827] nfsd: fh_verify(28:
> 00070001 0000a4c0 00000000 28ffa6c2 854703cf dd60c89a)
> Aug 12 11:21:34 srv1 kernel: [377723.629833] nfsd: nfsd_lookup(fh 28:
> 00070001 0000a4c0 00000000 28ffa6c2 854703cf dd60c89a, exports)
> Aug 12 11:21:34 srv1 kernel: [377723.629837] nfsd: fh_compose(exp
> fd:01/42176 tmp_export/exports, ino=37203)
> Aug 12 11:21:34 srv1 kernel: [377723.629842] nfsd: fh_verify(36:
> 01070001 0000a4c0 00000000 28ffa6c2 854703cf dd60c89a)
> Aug 12 11:21:34 srv1 kernel: [377723.629850] nfsd: fh_verify(36:
> 01070001 0000a4c0 00000000 28ffa6c2 854703cf dd60c89a)
> Aug 12 11:21:34 srv1 kernel: [377723.629857] [6809] NFSD
> get_new_stid(5208f000/000013bf/40174d7e/ffff8802)
> min_stateid[1075268991]/new_stid[1075268991]/error[0]
> Aug 12 11:21:34 srv1 kernel: [377723.629862] [6809]
> nfsd4_process_open2: stateid=(5208f000/000013bf/40174d7f/00000001)
> Aug 12 11:21:34 srv1 kernel: [377723.629866] nfsv4 compound op
> ffff8801f2015078 opcnt 5 #2: 18: status 0
> 
> As seen above min_stateid (1075268991) is what we ask IDR to use
> minimum ID to allocate & it also allocated this same number.
> 
> After this open, NFS client sends an OPEN_CONFIRM
> Aug 12 11:21:34 srv1 kernel: [377723.630528] nfsv4 compound op #2/2:
> 20 (OP_OPEN_CONFIRM)
> Aug 12 11:21:34 srv1 kernel: [377723.630530] [6809] NFSD:
> nfsd4_open_confirm on file exports
> Aug 12 11:21:34 srv1 kernel: [377723.630534] nfsd: fh_verify(36:
> 01070001 0000a4c0 00000000 28ffa6c2 854703cf dd60c89a)
> Aug 12 11:21:34 srv1 kernel: [377723.630538] [6809] NFSD:
> nfs4_preprocess_seqid_op: seqid=11033 stateid =
> (5208f000/000013bf/40174d7f/00000001)
> Aug 12 11:21:34 srv1 kernel: [377723.630542] [6809] renewing client
> (clientid 5208f000/000013bf)
> Aug 12 11:21:34 srv1 kernel: [377723.630549] [6809] bad_stateid -
> nfsd4_lookup_stateid: (5208f000/000013bf/40174d7f/00000001) -
> find_stateid_by_type() returned NULL. find_stateid() returned[NULL]
> stid->sc_type[0x0] typemask[0x1]
> Aug 12 11:21:34 srv1 kernel: [377723.630551] nfsv4 compound op
> ffff8801f2015078 opcnt 2 #2: 20: status 10025
> Aug 12 11:21:34 srv1 kernel: [377723.630554] nfsv4 compound returned 10025
> 
> As can be seen, we cant locate 40174d7f in IDR repository.
> 
> With debug infrastructure, dumped all the IDs of NFSD in IDR repository
> 
> Aug 12 11:21:34 srv1 kernel: [377723.631994] NFSD: Dumping Confirmed
> ID hashtable clients
> Aug 12 11:21:34 srv1 kernel: [377723.632000] NFSD:
> Client[conf_id_hashtbl] [5208f000/000013bf]
> Aug 12 11:21:34 srv1 kernel: [377723.632006]       NFSD:
> [5208f000/000013bf] IDR ID[1527167]
> (5208f000/000013bf/40174d7f/00000001) sc_type[1]
> Aug 12 11:21:34 srv1 kernel: [377723.632048]       NFSD: openowner
> [ffff88010b31ef50] oo_flags[0] so_seqid[11033] so_is_open_owner[1]]
> Aug 12 11:21:34 srv1 kernel: [377723.632052]               NFSD:
> nfs4_file stp[ffff88020ae36690] (5208f000/000013bf/40174d7f/00000001)
> sc_type[1] in zshare_id[1]
> Aug 12 11:21:34 srv1 kernel: [377723.632059] NFSD: Finished Dumping
> Confirmed ID hashtable clients
> 
> IDR has the ID as 1527167 for 0x40174d7f (1075268991)
> 
> i.e. IDR has representation like
> 
> 1075268991 – 1073741824 (2^30) = 1527167
> 
> Is it possible that you can fix NFSD till a proper fix is available in
> IDR? Thanks.
> 
> --Shyam
> 
> 
> On Wed, Jun 26, 2013 at 2:51 AM, J. Bruce Fields <bfields@fieldses.org> wrote:
> > On Tue, Jun 25, 2013 at 10:29:00PM +0530, Shyam Kaushik wrote:
> >> Hi,
> >>
> >> I looked up at this issue further & see the problem is this:
> >> # Client sends OPEN() of a file & as part of this NFSD server sets up
> >> a stateid & returns to the client.
> >> # Client comes back immediately with OPEN_CONFIRM() presenting the
> >> same stateid & NFSD server replies back that its a bad-stateid.
> >>
> >> Here are some pieces from tcpdump:
> >> NFS client comes with an OPEN of a file
> >> 10.189253 10.0.27.163 172.31.240.116 NFS 326 V4 Call (Reply In 8264)
> >> OPEN DH:0xfe4b0254/index.html
> >>          share_access: OPEN4_SHARE_ACCESS_READ (1)
> >>          share_deny: OPEN4_SHARE_DENY_NONE (0)
> >>          clientid: 0xcb76ab5114000000
> >>          Claim Type: CLAIM_NULL (0)
> >>
> >> NFS server reply
> >> 10.457226 172.31.240.116 10.0.27.163 NFS 498 V4 Reply (Call In 8057)
> >> OPEN StateID:0x50ee
> >>         Status: NFS4_OK (0)
> >>         StateID Hash: 0x50ee
> >>         seqid: 0x00000001
> >>         Data: cb76ab5114000000c4ca2540
> >>         1. = OPEN4_RESULT_CONFIRM
> >>         Delegation Type: OPEN_DELEGATE_NONE (0)
> >>
> >>
> >> Client comes back with OPEN_CONFIRM
> >> 10.459343 10.0.27.163 172.31.240.116 NFS 238 V4 Call (Reply In 8465)
> >> OPEN_CONFIRM
> >>         StateID Hash: 0x50ee
> >>         seqid: 0x00000001
> >>         Data: cb76ab5114000000c4ca2540
> >>
> >> Server replies with bad-stateid
> >> 10.733341 172.31.240.116 10.0.27.163 NFS 122 V4 Reply (Call In 8275)
> >> OPEN_CONFIRM Status: NFS4ERR_BAD_STATEID
> >>         Status: NFS4ERR_BAD_STATEID (10025)
> >
> > That does look like a server bug.  But I have trouble seeing how that's
> > happening (or why you would be able to reproduce it and not me).
> >
> > On the final OPEN_CONFIRM the server is either failing to find the
> > stateid or found it and thinks it's been closed or already confirmed.
> >
> > This is a different case from the one below where the server returns
> > BAD_STATEID on the write.
> >
> >> This keeps happening & nothing really progresses.
> >>
> >> Any thoughts/ideas on how to debug this further greatly appreciated.
> >
> > Off hand all I can suggest is tracing through the code (worst case,
> > sprinkling some printk's around) to figure out exactly where the
> > bad_stateid is being returned from originally.
> >
> > Or running a git bisect if you have a known-good kernel.
> >
> > Or if there's anything particular about your workload that you could
> > tell us so someone else could attempt to reproduce it.
> >
> > Also it's interesting if you can verify whether this is reproduceable on
> > newer kernels.
> >
> > --b.
> >
> >>
> >> Thanks.
> >>
> >> --Shyam
> >>
> >> On Mon, Jun 24, 2013 at 10:43 PM, Shyam Kaushik <shyamnfs1@gmail.com> wrote:
> >> > Hi Folks,
> >> >
> >> > Need help regarding a strange NFS server issue on 3.2 kernel.
> >> >
> >> > We are running a NFS server on Ubuntu precise with 3.2.0-25-generic
> >> > #40-Ubuntu kernel.
> >> >
> >> > We have several NFS exports out of this server & multiple clients
> >> > running different versions of linux kernel consume these exports. We
> >> > use ext4 with sync mount as the filesystem.
> >> >
> >> > We periodically see that all NFS activity comes to a standstill on all
> >> > NFS exports. Enabling NFS debug shows that there are numerous
> >> > nfserr_bad_stateid on almost all operations. This makes all of the
> >> > NFSD threads to consume all of CPU on the server.
> >> >
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.342457] nfsd_dispatch: vers 4 proc 1
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.342457] nfsv4 compound op
> >> > #1/7: 22 (OP_PUTFH)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.342467] nfsv4 compound op
> >> > ffff880095744078 opcnt 3 #1: 22: status 0
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.342472] nfsv4 compound op
> >> > #2/3: 38 (OP_WRITE)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.342472] nfsd: fh_verify(36:
> >> > 01070001 00d40001 00000000 ac63c188 0a4859a1 feb41e83)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.342484] renewing client
> >> > (clientid 51ab76cb/00005fc9)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.342486] NFSD: nfsd4_write:
> >> > couldn't process stateid!
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.342529] nfsv4 compound op
> >> > ffff880095744078 opcnt 3 #2: 38: status 10025
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.342544] nfsv4 compound returned 10025
> >> >
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.444116] nfsd_dispatch: vers 4 proc 1
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.444122] nfsv4 compound op
> >> > #1/3: 22 (OP_PUTFH)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.444125] nfsd: fh_verify(36:
> >> > 01070001 00020001 00000000 eb3726ca c8497c28 911b4a8d)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.444134] nfsv4 compound op
> >> > ffff880093436078 opcnt 3 #1: 22: status 0
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.444136] nfsv4 compound op
> >> > #2/3: 38 (OP_WRITE)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.446920] nfsd4_process_open2:
> >> > stateid=(51ab76cb/0000000b/40259544/00000001)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.446925] nfsv4 compound op
> >> > ffff880095027078 opcnt 7 #3: 18: status 0
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.446929] renewing client
> >> > (clientid 51ab76cb/00000022)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.446929] NFSD: nfsd4_write:
> >> > couldn't process stateid!
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.446929] nfsv4 compound op
> >> > ffff880093436078 opcnt 3 #2: 38: status 10025
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.446929] nfsv4 compound returned 10025
> >> >
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.447162] nfsd_dispatch: vers 4 proc 1
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.447163] nfsd: fh_verify(36:
> >> > 01070001 00240001 00000000 a80fc170 1947ae6c 4fbf37b1)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.447163] NFSD:
> >> > nfs4_preprocess_seqid_op: seqid=1 stateid =
> >> > (51ab76cb/00004b96/40259528/00000001)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.447181] nfsv4 compound op
> >> > #1/7: 22 (OP_PUTFH)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.447185] nfsd: fh_verify(28:
> >> > 00070001 00020001 00000000 53c0b8df a948fcb9 475e2cba)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.447185] renewing client
> >> > (clientid 51ab76cb/00004b96)
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.447187] nfsv4 compound op
> >> > ffff88000813f078 opcnt 2 #2: 20: status 10025
> >> > Jun 24 01:50:42 srv007 kernel: [5753609.447189] nfsv4 compound returned 10025
> >> >
> >> > NFSD stacks are like:
> >> > [<ffffffffa022e765>] nfs4_lock_state+0x15/0x40 [nfsd]
> >> > [<ffffffffa02234f4>] nfsd4_open+0xb4/0x440 [nfsd]
> >> > [<ffffffffa0221bc8>] nfsd4_proc_compound+0x518/0x6d0 [nfsd]
> >> > [<ffffffffa020fa0b>] nfsd_dispatch+0xeb/0x230 [nfsd]
> >> > [<ffffffffa0131d95>] svc_process_common+0x345/0x690 [sunrpc]
> >> > [<ffffffffa01321e2>] svc_process+0x102/0x150 [sunrpc]
> >> > [<ffffffffa020f0bd>] nfsd+0xbd/0x160 [nfsd]
> >> > [<ffffffff8108a59c>] kthread+0x8c/0xa0
> >> > [<ffffffff81667db4>] kernel_thread_helper+0x4/0x10
> >> > [<ffffffffffffffff>] 0xffffffffffffffff
> >> >
> >> > I couldnt exactly capture the running thread, but it appears that one
> >> > thread of the NFSD thread pool runs & detects a bad-state-id & returns
> >> > back.
> >> >
> >> > Is this a known issue or any help on how to dig in further is greatly
> >> > appreciated.
> >> >
> >> > Thanks.
> >> >
> >> > --Shyam
> >> --
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