Re: [PATCH v2] NFSv4.1: Fix up replays of interrupted requests

[bfields@fieldses.org (J. Bruce Fields)]

On Mon, Oct 16, 2017 at 01:07:57PM -0400, Olga Kornievskaia wrote:
> Network trace reveals that server is not working properly (thus
> getting Bruce's attention here).
> 
> Skipping ahead, the server replies to a SEQUENCE call with a reply
> that has a count=5 operations but only has a sequence in it.
> 
> The flow of steps is the following.
> 
> Client sends
> call COPY seq=16 slot=0 highslot=1(application at this point receives
> a ctrl-c so it'll go ahead and close 2files it has opened)

Is cachethis set on that the SEQUENCE op in that copy compound?

> call CLOSE  seq=1 slot=1 highslot=1
> call SEQUENCE seq=16 slot=0 highslot=1
> reply CLOSE OK
> reply SEQUENCE ERR_DELAY
> another call CLOSE seq=2 slot=1 and successful reply
> reply COPY ..
> call SEQUENCE seq=16 slot=0 highslot=0
> reply SEQUENCE opcount=5

And that's the whole reply?

Do you have a binary capture that I could look at?

> So I'm assuming server is replying from the reply cache for the COPY
> seq=16 slot=0.. but it's only sending part of it back? Is that legit?

No.--b.

> 
> In any case, I think the client shouldn't be oops-ing.
> 
> [  138.136387] BUG: unable to handle kernel NULL pointer dereference
> at 0000000000000020^M
> [  138.140134] IP: _nfs41_proc_sequence+0xdd/0x1a0 [nfsv4]^M
> [  138.141687] PGD 0 P4D 0 ^M
> [  138.142462] Oops: 0002 [#1] SMP^M
> [  138.143413] Modules linked in: nfsv4 dns_resolver nfs rfcomm fuse
> xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun ip6t_rpfilter
> ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 xt_conntrack
> ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc
> ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6
> ip6table_mangle ip6table_security ip6table_raw iptable_nat
> nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack
> libcrc32c iptable_mangle iptable_security iptable_raw ebtable_filter
> ebtables ip6table_filter ip6_tables iptable_filter
> vmw_vsock_vmci_transport vsock bnep dm_mirror dm_region_hash dm_log
> dm_mod snd_seq_midi snd_seq_midi_event coretemp crct10dif_pclmul
> crc32_pclmul ghash_clmulni_intel pcbc uvcvideo snd_ens1371
> snd_ac97_codec ac97_bus snd_seq ppdev videobuf2_vmalloc^M
> [  138.158839]  btusb videobuf2_memops videobuf2_v4l2 videobuf2_core
> aesni_intel btrtl nfit btbcm crypto_simd cryptd videodev snd_pcm
> btintel glue_helper vmw_balloon libnvdimm bluetooth snd_rawmidi
> snd_timer pcspkr snd_seq_device snd shpchp rfkill vmw_vmci sg
> ecdh_generic soundcore i2c_piix4 parport_pc parport nfsd auth_rpcgss
> nfs_acl lockd grace sunrpc ip_tables ext4 mbcache jbd2 sr_mod cdrom
> sd_mod ata_generic pata_acpi vmwgfx drm_kms_helper syscopyarea
> sysfillrect sysimgblt fb_sys_fops ttm drm ahci libahci crc32c_intel
> ata_piix mptspi scsi_transport_spi serio_raw libata mptscsih e1000
> mptbase i2c_core^M
> [  138.169453] CPU: 3 PID: 541 Comm: kworker/3:3 Not tainted 4.14.0-rc5+ #41^M
> [  138.170829] Hardware name: VMware, Inc. VMware Virtual
> Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015^M
> [  138.172960] Workqueue: events nfs4_renew_state [nfsv4]^M
> [  138.174020] task: ffff880033c80000 task.stack: ffffc90000d80000^M
> [  138.175232] RIP: 0010:_nfs41_proc_sequence+0xdd/0x1a0 [nfsv4]^M
> [  138.176392] RSP: 0018:ffffc90000d83d68 EFLAGS: 00010246^M
> [  138.177444] RAX: ffff880073646200 RBX: ffff88002c944800 RCX:
> 0000000000000000^M
> [  138.178932] RDX: 00000000fffd7000 RSI: 0000000000000000 RDI:
> ffff880073646240^M
> [  138.180357] RBP: ffffc90000d83df8 R08: 000000000001ee40 R09:
> ffff880073646200^M
> [  138.181955] R10: ffff880073646200 R11: 0000000000000139 R12:
> ffffc90000d83d90^M
> [  138.184014] R13: 0000000000000000 R14: 0000000000000000 R15:
> ffffffffa08784d0^M
> [  138.185439] FS:  0000000000000000(0000) GS:ffff88007b6c0000(0000)
> knlGS:0000000000000000^M
> [  138.187144] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033^M
> [  138.188469] CR2: 0000000000000020 CR3: 0000000001c09003 CR4:
> 00000000001606e0^M
> [  138.189952] Call Trace:^M
> [  138.190478]  nfs41_proc_async_sequence+0x1d/0x60 [nfsv4]^M
> [  138.191549]  nfs4_renew_state+0x10b/0x1a0 [nfsv4]^M
> [  138.192555]  process_one_work+0x149/0x360^M
> [  138.193367]  worker_thread+0x4d/0x3c0^M
> [  138.194157]  kthread+0x109/0x140^M
> [  138.194816]  ? rescuer_thread+0x380/0x380^M
> [  138.195673]  ? kthread_park+0x60/0x60^M
> [  138.196426]  ret_from_fork+0x25/0x30^M
> [  138.197153] Code: e0 48 85 c0 0f 84 8e 00 00 00 0f b6 50 10 48 c7
> 40 08 00 00 00 00 48 c7 40 18 00 00 00 00 83 e2 fc 88 50 10 48 8b 15
> b3 0e 3c e1 <41> 80 66 20 fd 45 84 ed 4c 89 70 08 4c 89 70 18 c7 40 2c
> 00 00 ^M
> [  138.200991] RIP: _nfs41_proc_sequence+0xdd/0x1a0 [nfsv4] RSP:
> ffffc90000d83d68^M
> [  138.202431] CR2: 0000000000000020^M
> [  138.203200] ---[ end trace b25c7be5ead1a406 ]---^M
> 
> >>
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