Hi, On 3/19/24 22:42, Dai Ngo wrote:
On 3/19/24 12:41 PM, Rik Theys wrote:Hi, On 3/19/24 18:09, Dai Ngo wrote:On 3/19/24 12:58 AM, Rik Theys wrote:Hi, On 3/18/24 22:54, Jeff Layton wrote:No, the server runs 5.14.0-427.3689_1194299994.el9 and the client 5.14.0-362.18.1.el9_3.On Mon, 2024-03-18 at 22:15 +0100, Rik Theys wrote:Hi, On 3/18/24 21:21, Rik Theys wrote:Hi Jeff, On 3/12/24 13:47, Jeff Layton wrote:On Tue, 2024-03-12 at 13:24 +0100, Rik Theys wrote:419 is fairly up to date with nfsd changes. There are some known bugsHi Jeff, On 3/12/24 12:22, Jeff Layton wrote:On Mon, 2024-03-11 at 19:43 +0100, Rik Theys wrote:Since a few weeks our Rocky Linux 9 NFS server has periodicallylogged hung nfsd tasks. The initial effect was that some clientscould no longer access the NFS server. This got worse and worse(probably as more nfsd threads got blocked) and we had to restartthe server. Restarting the server also failed as the NFS server service could no longer be stopped. The initial kernel we noticed this behavior on was kernel-5.14.0-362.18.1.el9_3.x86_64. Since then we've installedkernel-5.14.0-419.el9.x86_64 from CentOS Stream 9. The same issuehappened again on this newer kernel version:around callbacks, and there is a draft MR in flight to fix it.What kernel were you on prior to 5.14.0-362.18.1.el9_3.x86_64 ? If we can bracket the changes around a particular version, then that mighthelp identify the problem.If I read that thread correctly, this issue was introduced between[Mon Mar 11 14:10:08 2024] Not tainted 5.14.0-419.el9.x86_64 #1The above threads are trying to flush the workqueue, so that probably[Mon Mar 11 14:10:08 2024] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.[Mon Mar 11 14:10:08 2024]task:nfsd state:D stack:0pid:8865 ppid:2 flags:0x00004000 [Mon Mar 11 14:10:08 2024] Call Trace: [Mon Mar 11 14:10:08 2024] <TASK> [Mon Mar 11 14:10:08 2024] __schedule+0x21b/0x550 [Mon Mar 11 14:10:08 2024] schedule+0x2d/0x70 [Mon Mar 11 14:10:08 2024] schedule_timeout+0x11f/0x160[Mon Mar 11 14:10:08 2024] ? select_idle_sibling+0x28/0x430[Mon Mar 11 14:10:08 2024] ? wake_affine+0x62/0x1f0 [Mon Mar 11 14:10:08 2024] __wait_for_common+0x90/0x1d0[Mon Mar 11 14:10:08 2024] ? __pfx_schedule_timeout+0x10/0x10[Mon Mar 11 14:10:08 2024] __flush_workqueue+0x13a/0x3f0[Mon Mar 11 14:10:08 2024] nfsd4_shutdown_callback+0x49/0x120[nfsd][Mon Mar 11 14:10:08 2024] ? nfsd4_cld_remove+0x54/0x1d0 [nfsd][Mon Mar 11 14:10:08 2024] ? nfsd4_return_all_client_layouts+0xc4/0xf0 [nfsd][Mon Mar 11 14:10:08 2024] ? nfsd4_shutdown_copy+0x68/0xc0 [nfsd] [Mon Mar 11 14:10:08 2024] __destroy_client+0x1f3/0x290 [nfsd] [Mon Mar 11 14:10:08 2024] nfsd4_exchange_id+0x75f/0x770 [nfsd] [Mon Mar 11 14:10:08 2024] ? nfsd4_decode_opaque+0x3a/0x90 [nfsd] [Mon Mar 11 14:10:08 2024] nfsd4_proc_compound+0x44b/0x700 [nfsd][Mon Mar 11 14:10:08 2024] nfsd_dispatch+0x94/0x1c0 [nfsd] [Mon Mar 11 14:10:08 2024] svc_process_common+0x2ec/0x660 [sunrpc][Mon Mar 11 14:10:08 2024] ? __pfx_nfsd_dispatch+0x10/0x10 [nfsd][Mon Mar 11 14:10:08 2024] ? __pfx_nfsd+0x10/0x10 [nfsd][Mon Mar 11 14:10:08 2024] svc_process+0x12d/0x170 [sunrpc][Mon Mar 11 14:10:08 2024] nfsd+0x84/0xb0 [nfsd] [Mon Mar 11 14:10:08 2024] kthread+0xdd/0x100 [Mon Mar 11 14:10:08 2024] ? __pfx_kthread+0x10/0x10 [Mon Mar 11 14:10:08 2024] ret_from_fork+0x29/0x50 [Mon Mar 11 14:10:08 2024] </TASK> [Mon Mar 11 14:10:08 2024] INFO: task nfsd:8866 blocked for more than 122 seconds. [Mon Mar 11 14:10:08 2024] Not tainted 5.14.0-419.el9.x86_64 #1 [Mon Mar 11 14:10:08 2024] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.[Mon Mar 11 14:10:08 2024]task:nfsd state:D stack:0pid:8866 ppid:2 flags:0x00004000 [Mon Mar 11 14:10:08 2024] Call Trace: [Mon Mar 11 14:10:08 2024] <TASK> [Mon Mar 11 14:10:08 2024] __schedule+0x21b/0x550 [Mon Mar 11 14:10:08 2024] schedule+0x2d/0x70 [Mon Mar 11 14:10:08 2024] schedule_timeout+0x11f/0x160[Mon Mar 11 14:10:08 2024] ? select_idle_sibling+0x28/0x430[Mon Mar 11 14:10:08 2024] ? tcp_recvmsg+0x196/0x210 [Mon Mar 11 14:10:08 2024] ? wake_affine+0x62/0x1f0 [Mon Mar 11 14:10:08 2024] __wait_for_common+0x90/0x1d0[Mon Mar 11 14:10:08 2024] ? __pfx_schedule_timeout+0x10/0x10[Mon Mar 11 14:10:08 2024] __flush_workqueue+0x13a/0x3f0[Mon Mar 11 14:10:08 2024] nfsd4_destroy_session+0x1a4/0x240[nfsd][Mon Mar 11 14:10:08 2024] nfsd4_proc_compound+0x44b/0x700 [nfsd][Mon Mar 11 14:10:08 2024] nfsd_dispatch+0x94/0x1c0 [nfsd] [Mon Mar 11 14:10:08 2024] svc_process_common+0x2ec/0x660 [sunrpc][Mon Mar 11 14:10:08 2024] ? __pfx_nfsd_dispatch+0x10/0x10 [nfsd][Mon Mar 11 14:10:08 2024] ? __pfx_nfsd+0x10/0x10 [nfsd][Mon Mar 11 14:10:08 2024] svc_process+0x12d/0x170 [sunrpc][Mon Mar 11 14:10:08 2024] nfsd+0x84/0xb0 [nfsd] [Mon Mar 11 14:10:08 2024] kthread+0xdd/0x100 [Mon Mar 11 14:10:08 2024] ? __pfx_kthread+0x10/0x10 [Mon Mar 11 14:10:08 2024] ret_from_fork+0x29/0x50 [Mon Mar 11 14:10:08 2024] </TASK>means that they are stuck waiting on a workqueue job to finish.The above is repeated a few times, and then this warning is also logged:[Mon Mar 11 14:12:04 2024] ------------[ cut here ]------------[Mon Mar 11 14:12:04 2024] WARNING: CPU: 39 PID: 8844 at fs/nfsd/nfs4state.c:4919 nfsd_break_deleg_cb+0x170/0x190 [nfsd] [Mon Mar 11 14:12:05 2024] Modules linked in: nfsv4 dns_resolver nfs fscache netfs rpcsec_gss_krb5 rpcrdma rdma_cmiw_cm ib_cm ib_core binfmt_misc bonding tls rfkill nft_counter nft_ctnf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_reject_inetnf_reject_ipv4 nf_reject_ipv6 nft_reject nf_tables nfnetlink vfatfat dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio l ibcrc32c dm_service_time dm_multipath intel_rapl_msr intel_rapl_common intel_uncore_frequency intel_uncore_frequency_common isst_if_common skx_edac nfit libnvdimm ipmi_ssif x86_pkg_temp _thermal intel_powerclamp coretemp kvm_intel kvm irqbypass dcdbas rapl intel_cstate mgag200 i2c_algo_bit drm_shmem_helper dell_smbios drm_kms_helper dell_wmi_descriptor wmi_bmof intel_uncore syscopyarea pcspkr sysfillrect mei_me sysimgblt acpi_ipmimei fb_sys_fops i2c_i801 ipmi_si intel_pch_thermal lpc_ich ipmi_devintf i2c_smbus ipmi_msghandler joydev acpi_power_meter nfsd auth_rpcgss nfs_acl drm lockd grace fuse sunrpc ext4 mbcache jbd2 sd_mod sg lpfc[Mon Mar 11 14:12:05 2024] nvmet_fc nvmet nvme_fc nvme_fabrics crct10dif_pclmul ahci libahci crc32_pclmul nvme_core crc32c_intelixgbe megaraid_sas libata nvme_common ghash_clmulni_int el t10_pi wdat_wdt scsi_transport_fc mdio wmi dca dm_mirror dm_region_hash dm_log dm_mod [Mon Mar 11 14:12:05 2024] CPU: 39 PID: 8844 Comm: nfsd Not tainted 5.14.0-419.el9.x86_64 #1[Mon Mar 11 14:12:05 2024] Hardware name: Dell Inc. PowerEdgeR740/00WGD1, BIOS 2.20.1 09/13/2023 [Mon Mar 11 14:12:05 2024] RIP: 0010:nfsd_break_deleg_cb+0x170/0x190 [nfsd][Mon Mar 11 14:12:05 2024] Code: a6 95 c5 f3 e9 ff fe ff ff 48 89 df be 01 00 00 00 e8 34 b5 13 f4 48 8d bb 98 00 00 00 e8 c8 f900 00 84 c0 0f 85 2e ff ff ff <0f> 0b e9 27 ff ff ff be 02 00 00 00 48 89 df e8 0c b5 13 f4 e9 01[Mon Mar 11 14:12:05 2024] RSP: 0018:ffff9929e0bb7b80 EFLAGS:00010246 [Mon Mar 11 14:12:05 2024] RAX: 0000000000000000 RBX: ffff8ada51930900 RCX: 0000000000000024 [Mon Mar 11 14:12:05 2024] RDX: ffff8ada519309c8 RSI: ffff8ad582933c00 RDI: 0000000000002000 [Mon Mar 11 14:12:05 2024] RBP: ffff8ad46bf21574 R08: ffff9929e0bb7b48 R09: 0000000000000000 [Mon Mar 11 14:12:05 2024] R10: ffff8aec859a2948 R11: 0000000000000000 R12: ffff8ad6f497c360 [Mon Mar 11 14:12:05 2024] R13: ffff8ad46bf21560 R14: ffff8ae5942e0b10 R15: ffff8ad6f497c360 [Mon Mar 11 14:12:05 2024] FS: 0000000000000000(0000) GS:ffff8b031fcc0000(0000) knlGS:0000000000000000 [Mon Mar 11 14:12:05 2024] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [Mon Mar 11 14:12:05 2024] CR2: 00007fafe2060744 CR3: 00000018e58de006 CR4: 00000000007706e0 [Mon Mar 11 14:12:05 2024] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [Mon Mar 11 14:12:05 2024] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [Mon Mar 11 14:12:05 2024] PKRU: 55555554 [Mon Mar 11 14:12:05 2024] Call Trace: [Mon Mar 11 14:12:05 2024] <TASK>[Mon Mar 11 14:12:05 2024] ? show_trace_log_lvl+0x1c4/0x2df [Mon Mar 11 14:12:05 2024] ? show_trace_log_lvl+0x1c4/0x2df[Mon Mar 11 14:12:05 2024] ? __break_lease+0x16f/0x5f0[Mon Mar 11 14:12:05 2024] ? nfsd_break_deleg_cb+0x170/0x190[nfsd] [Mon Mar 11 14:12:05 2024] ? __warn+0x81/0x110[Mon Mar 11 14:12:05 2024] ? nfsd_break_deleg_cb+0x170/0x190[nfsd] [Mon Mar 11 14:12:05 2024] ? report_bug+0x10a/0x140 [Mon Mar 11 14:12:05 2024] ? handle_bug+0x3c/0x70 [Mon Mar 11 14:12:05 2024] ? exc_invalid_op+0x14/0x70 [Mon Mar 11 14:12:05 2024] ? asm_exc_invalid_op+0x16/0x20[Mon Mar 11 14:12:05 2024] ? nfsd_break_deleg_cb+0x170/0x190[nfsd] [Mon Mar 11 14:12:05 2024] __break_lease+0x16f/0x5f0 [Mon Mar 11 14:12:05 2024] ? nfsd_file_lookup_locked+0x117/0x160 [nfsd] [Mon Mar 11 14:12:05 2024] ? list_lru_del+0x101/0x150[Mon Mar 11 14:12:05 2024] nfsd_file_do_acquire+0x790/0x830[nfsd][Mon Mar 11 14:12:05 2024] nfs4_get_vfs_file+0x315/0x3a0 [nfsd] [Mon Mar 11 14:12:05 2024] nfsd4_process_open2+0x430/0xa30 [nfsd][Mon Mar 11 14:12:05 2024] ? fh_verify+0x297/0x2f0 [nfsd] [Mon Mar 11 14:12:05 2024] nfsd4_open+0x3ce/0x4b0 [nfsd][Mon Mar 11 14:12:05 2024] nfsd4_proc_compound+0x44b/0x700 [nfsd][Mon Mar 11 14:12:05 2024] nfsd_dispatch+0x94/0x1c0 [nfsd] [Mon Mar 11 14:12:05 2024] svc_process_common+0x2ec/0x660 [sunrpc][Mon Mar 11 14:12:05 2024] ? __pfx_nfsd_dispatch+0x10/0x10 [nfsd][Mon Mar 11 14:12:05 2024] ? __pfx_nfsd+0x10/0x10 [nfsd][Mon Mar 11 14:12:05 2024] svc_process+0x12d/0x170 [sunrpc][Mon Mar 11 14:12:05 2024] nfsd+0x84/0xb0 [nfsd] [Mon Mar 11 14:12:05 2024] kthread+0xdd/0x100 [Mon Mar 11 14:12:05 2024] ? __pfx_kthread+0x10/0x10 [Mon Mar 11 14:12:05 2024] ret_from_fork+0x29/0x50 [Mon Mar 11 14:12:05 2024] </TASK>[Mon Mar 11 14:12:05 2024] ---[ end trace 7a039e17443dc651 ]---This is probably this WARN in nfsd_break_one_deleg: WARN_ON_ONCE(!nfsd4_run_cb(&dp->dl_recall));It means that a delegation break callback to the client couldn't bequeued to the workqueue, and so it didn't run.Could this be the same issue as describedhere:https://urldefense.com/v3/__https://lore.kernel.org/linux-nfs/af0ec881-5ebf-4feb-98ae-3ed2a77f86f1@xxxxxxxxxx/__;!!ACWV5N9M2RV99hQ!LV3yWeoSOhNAkRHkxFCH2tlm0iNFVD78mxnSLyP6lrX7yBVeA2TOJ4nv6oZsqLwP4kW56CMpDWhkjjwSkdBV9En7$ ?Yes, most likely the same problem.6.1.63 and 6.6.3? Is it possible the EL9 5.14.0-362.18.1.el9_3backported these changes, or were we hitting some other bug with thatversion? It seems the 6.1.x kernel is not affected? If so, that would be the recommended kernel to run?Anything is possible. We have to identify the problem first.It's probably simpler to just pull down the build artifacts for that MR.If you can send me a patch file, I can rebuild the C9S kernel with thatAs described in that thread, I've tried to obtain the requested information. Is it possible this is the issue that was fixed by the patches describedhere?https://urldefense.com/v3/__https://lore.kernel.org/linux-nfs/2024022054-cause-suffering-eae8@gregkh/__;!!ACWV5N9M2RV99hQ!LV3yWeoSOhNAkRHkxFCH2tlm0iNFVD78mxnSLyP6lrX7yBVeA2TOJ4nv6oZsqLwP4kW56CMpDWhkjjwSkedtUP09$Doubtful. Those are targeted toward a different set of issues.If you're willing, I do have some patches queued up for CentOS herethat fix some backchannel problems that could be related. I'm mainly waitingon Chuck to send these to Linus and then we'll likely merge them intoCentOS soon afterward:https://urldefense.com/v3/__https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/3689__;!!ACWV5N9M2RV99hQ!LV3yWeoSOhNAkRHkxFCH2tlm0iNFVD78mxnSLyP6lrX7yBVeA2TOJ4nv6oZsqLwP4kW56CMpDWhkjjwSkdvDn8y7$patch and run it. It can take a while for the bug to trigger as Ibelieve it seems to be very workload dependent (we were running verystable for months and now hit this bug every other week).You have to drill down through the CI for it, but they are here:https://urldefense.com/v3/__https://s3.amazonaws.com/arr-cki-prod-trusted-artifacts/index.html?prefix=trusted-artifacts*1194300175*publish_x86_64*6278921877*artifacts*__;Ly8vLy8!!ACWV5N9M2RV99hQ!LV3yWeoSOhNAkRHkxFCH2tlm0iNFVD78mxnSLyP6lrX7yBVeA2TOJ4nv6oZsqLwP4kW56CMpDWhkjjwSkaP5eW8V$There's even a repo file you can install on the box to pull them down.We installed this kernel on the server 3 days ago. Today, a userinformed us that their screen was black after logging in. Similar to other occurrences of this issue, the mount command on the client washung. But in contrast to the other times, there were no messages in the logs kernel logs on the server. Even restarting the client does not resolve the issue.Ok, so you rebooted the client and it's still unable to mount? That sounds like a server problem if so. Are both client and server running the same kernel?Is there a way to force such a conflicting request (to get the client record to purge)?If you just shut down the client, the server won't immediately purge its record. In fact, assuming you're running the same kernel on the server,Something still seems to be wrong on the server though. When I look at the directories under /proc/fs/nfsd/clients, there's still a directoryfor the specific client, even though it's no longer running: # cat 155/info clientid: 0xc8edb7f65f4a9ad address: "10.87.31.152:819" status: confirmed seconds from last renew: 33163 name: "Linux NFSv4.2 bersalis.esat.kuleuven.be" minor version: 2 Implementation domain: "kernel.org" Implementation name: "Linux 5.14.0-362.18.1.el9_3.0.1.x86_64 #1 SMP PREEMPT_DYNAMIC Sun Feb 11 13:49:23 UTC 2024 x86_64" Implementation time: [0, 0] callback state: DOWN callback address: 10.87.31.152:0it won't purge the client record until there is a conflicting request for its state.Try: # echo "expire" > /proc/fs/nfsd/clients/155/ctlI've tried that. The command hangs and can not be interrupted with ctrl-c. I've now also noticed in the dmesg output that the kernel issued the following WARNING a few hours ago. It wasn't directly triggered by the echo command above, but seems to have been triggered a few hours ago (probably when another client started to have the same problem as more clients are experiencing issues now).I think this warning message is harmless. However it indicates potential problem with the workqueue which might be related to memory shortage. What the output of 'cat /proc/meminfo' looks like?
I doubt the current values are useful, but they are: MemTotal: 196110860 kB MemFree: 29357112 kB MemAvailable: 179529420 kB Buffers: 11996096 kB Cached: 130589396 kB SwapCached: 52 kB Active: 1136988 kB Inactive: 144192468 kB Active(anon): 698564 kB Inactive(anon): 2657256 kB Active(file): 438424 kB Inactive(file): 141535212 kB Unevictable: 72140 kB Mlocked: 69068 kB SwapTotal: 67108860 kB SwapFree: 67106276 kB Zswap: 0 kB Zswapped: 0 kB Dirty: 80812 kB Writeback: 0 kB AnonPages: 2806592 kB Mapped: 322700 kB Shmem: 599308 kB KReclaimable: 16977000 kB Slab: 18898736 kB SReclaimable: 16977000 kB SUnreclaim: 1921736 kB KernelStack: 18128 kB PageTables: 31716 kB SecPageTables: 0 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 165164288 kB Committed_AS: 5223940 kB VmallocTotal: 34359738367 kB VmallocUsed: 300064 kB VmallocChunk: 0 kB Percpu: 45888 kB HardwareCorrupted: 0 kB AnonHugePages: 2451456 kB ShmemHugePages: 0 kB ShmemPmdMapped: 0 kB FileHugePages: 0 kB FilePmdMapped: 0 kB CmaTotal: 0 kB CmaFree: 0 kB Unaccepted: 0 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB Hugetlb: 0 kB DirectMap4k: 1303552 kB DirectMap2M: 28715008 kB DirectMap1G: 171966464 kB
Did you try 'echo 3 > /proc/sys/vm/drop_caches'?
Yes, I tried that when the first client hit the issue, but it didn't result in any unlocking of the client.
It seems odd that the system gets in such a state that has such high memory pressure. It doesn't run much else than NFS and Samba.[Tue Mar 19 14:53:44 2024] ------------[ cut here ]------------[Tue Mar 19 14:53:44 2024] WARNING: CPU: 44 PID: 5843 at fs/nfsd/nfs4state.c:4920 nfsd_break_deleg_cb+0x170/0x190 [nfsd] [Tue Mar 19 14:53:44 2024] Modules linked in: nf_conntrack_netlink nfsv4 dns_resolver nfs fscache netfs binfmt_misc xsk_diag rpcsec_gss_krb5 rpcrdma rdma_cm iw_cm ib_cm ib_core bonding tls rfkill nft_counter nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nf_tables nfnetlink vfat fat dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio libcrc32c dm_service_time dm_multipath intel_rapl_msr intel_rapl_common intel_uncore_frequency intel_uncore_frequency_common isst_if_common skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm dcdbas irqbypass ipmi_ssif rapl intel_cstate mgag200 i2c_algo_bit drm_shmem_helper drm_kms_helper dell_smbios syscopyarea intel_uncore sysfillrect wmi_bmof dell_wmi_descriptor pcspkr sysimgblt fb_sys_fops mei_me i2c_i801 mei intel_pch_thermal acpi_ipmi i2c_smbus lpc_ich ipmi_si ipmi_devintf ipmi_msghandler joydev acpi_power_meter nfsd nfs_acl lockd auth_rpcgss grace drm fuse sunrpc ext4 [Tue Mar 19 14:53:44 2024] mbcache jbd2 sd_mod sg lpfc nvmet_fc nvmet nvme_fc nvme_fabrics crct10dif_pclmul crc32_pclmul nvme_core ixgbe crc32c_intel ahci libahci nvme_common megaraid_sas t10_pi ghash_clmulni_intel wdat_wdt libata scsi_transport_fc mdio dca wmi dm_mirror dm_region_hash dm_log dm_mod [Tue Mar 19 14:53:44 2024] CPU: 44 PID: 5843 Comm: nfsd Not tainted 5.14.0-427.3689_1194299994.el9.x86_64 #1 [Tue Mar 19 14:53:44 2024] Hardware name: Dell Inc. PowerEdge R740/00WGD1, BIOS 2.20.1 09/13/2023 [Tue Mar 19 14:53:44 2024] RIP: 0010:nfsd_break_deleg_cb+0x170/0x190 [nfsd] [Tue Mar 19 14:53:44 2024] Code: 76 76 cd de e9 ff fe ff ff 48 89 df be 01 00 00 00 e8 34 a1 1b df 48 8d bb 98 00 00 00 e8 a8 fe 00 00 84 c0 0f 85 2e ff ff ff <0f> 0b e9 27 ff ff ff be 02 00 00 00 48 89 df e8 0c a1 1b df e9 01[Tue Mar 19 14:53:44 2024] RSP: 0018:ffffb2878f2cfc38 EFLAGS: 00010246[Tue Mar 19 14:53:44 2024] RAX: 0000000000000000 RBX: ffff88d5171067b8 RCX: 0000000000000000 [Tue Mar 19 14:53:44 2024] RDX: ffff88d517106880 RSI: ffff88bdceec8600 RDI: 0000000000002000 [Tue Mar 19 14:53:44 2024] RBP: ffff88d68a38a284 R08: ffffb2878f2cfc00 R09: 0000000000000000 [Tue Mar 19 14:53:44 2024] R10: ffff88bf57dd7878 R11: 0000000000000000 R12: ffff88d5b79c4798 [Tue Mar 19 14:53:44 2024] R13: ffff88d68a38a270 R14: ffff88cab06ad0c8 R15: ffff88d5b79c4798 [Tue Mar 19 14:53:44 2024] FS: 0000000000000000(0000) GS:ffff88d4a1180000(0000) knlGS:0000000000000000 [Tue Mar 19 14:53:44 2024] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [Tue Mar 19 14:53:44 2024] CR2: 00007fe46ef90000 CR3: 000000019d010004 CR4: 00000000007706e0 [Tue Mar 19 14:53:44 2024] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [Tue Mar 19 14:53:44 2024] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400[Tue Mar 19 14:53:44 2024] PKRU: 55555554 [Tue Mar 19 14:53:44 2024] Call Trace: [Tue Mar 19 14:53:44 2024] <TASK> [Tue Mar 19 14:53:44 2024] ? show_trace_log_lvl+0x1c4/0x2df [Tue Mar 19 14:53:44 2024] ? show_trace_log_lvl+0x1c4/0x2df [Tue Mar 19 14:53:44 2024] ? __break_lease+0x16f/0x5f0 [Tue Mar 19 14:53:44 2024] ? nfsd_break_deleg_cb+0x170/0x190 [nfsd] [Tue Mar 19 14:53:44 2024] ? __warn+0x81/0x110 [Tue Mar 19 14:53:44 2024] ? nfsd_break_deleg_cb+0x170/0x190 [nfsd] [Tue Mar 19 14:53:44 2024] ? report_bug+0x10a/0x140 [Tue Mar 19 14:53:44 2024] ? handle_bug+0x3c/0x70 [Tue Mar 19 14:53:44 2024] ? exc_invalid_op+0x14/0x70 [Tue Mar 19 14:53:44 2024] ? asm_exc_invalid_op+0x16/0x20 [Tue Mar 19 14:53:44 2024] ? nfsd_break_deleg_cb+0x170/0x190 [nfsd] [Tue Mar 19 14:53:44 2024] ? nfsd_break_deleg_cb+0x96/0x190 [nfsd] [Tue Mar 19 14:53:44 2024] __break_lease+0x16f/0x5f0 [Tue Mar 19 14:53:44 2024] nfs4_get_vfs_file+0x164/0x3a0 [nfsd] [Tue Mar 19 14:53:44 2024] nfsd4_process_open2+0x430/0xa30 [nfsd] [Tue Mar 19 14:53:44 2024] ? fh_verify+0x297/0x2f0 [nfsd] [Tue Mar 19 14:53:44 2024] nfsd4_open+0x3ce/0x4b0 [nfsd] [Tue Mar 19 14:53:44 2024] nfsd4_proc_compound+0x44b/0x700 [nfsd] [Tue Mar 19 14:53:44 2024] nfsd_dispatch+0x94/0x1c0 [nfsd] [Tue Mar 19 14:53:44 2024] svc_process_common+0x2ec/0x660 [sunrpc] [Tue Mar 19 14:53:44 2024] ? __pfx_nfsd_dispatch+0x10/0x10 [nfsd] [Tue Mar 19 14:53:44 2024] ? __pfx_nfsd+0x10/0x10 [nfsd] [Tue Mar 19 14:53:44 2024] svc_process+0x12d/0x170 [sunrpc] [Tue Mar 19 14:53:44 2024] nfsd+0x84/0xb0 [nfsd] [Tue Mar 19 14:53:44 2024] kthread+0xdd/0x100 [Tue Mar 19 14:53:44 2024] ? __pfx_kthread+0x10/0x10 [Tue Mar 19 14:53:44 2024] ret_from_fork+0x29/0x50 [Tue Mar 19 14:53:44 2024] </TASK> [Tue Mar 19 14:53:44 2024] ---[ end trace ed0b2b3f135c637d ]--- It again seems to have been triggered in nfsd_break_deleg_cb? I also had the following perf command running a tmux on the server: perf trace -e nfsd:nfsd_cb_recall_any This has spewed a lot of messages. I'm including a short list here: ...33464866.721 kworker/u98:5/1591466 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210688785, bmval0: 1, addr: 0x7f331bb116c8) 33464866.724 kworker/u98:5/1591466 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210688827, bmval0: 1, addr: 0x7f331bb11738) 33464866.729 kworker/u98:5/1591466 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210688767, bmval0: 1, addr: 0x7f331bb117a8) 33464866.732 kworker/u98:5/1591466 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210718132, bmval0: 1, addr: 0x7f331bb11818) 33464866.737 kworker/u98:5/1591466 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210688952, bmval0: 1, addr: 0x7f331bb11888) 33464866.741 kworker/u98:5/1591466 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210702355, bmval0: 1, addr: 0x7f331bb118f8) 33868414.001 kthreadd/1597068 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210688751, bmval0: 1, addr: 0x7f331be68620) 33868414.014 kthreadd/1597068 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210718536, bmval0: 1, addr: 0x7f331be68690) 33868414.018 kthreadd/1597068 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210719074, bmval0: 1, addr: 0x7f331be68700) 33868414.022 kthreadd/1597068 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210688916, bmval0: 1, addr: 0x7f331be68770) 33868414.026 kthreadd/1597068 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210688941, bmval0: 1, addr: 0x7f331be687e0)...33868414.924 kthreadd/1597068 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210688744, bmval0: 1, addr: 0x7f331be6d7f0) 33868414.929 kthreadd/1597068 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210717223, bmval0: 1, addr: 0x7f331be6d860) 33868414.934 kthreadd/1597068 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210716137, bmval0: 1, addr: 0x7f331be6d8d0) 34021240.903 kworker/u98:5/1591466 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210688941, bmval0: 1, addr: 0x7f331c207de8) 34021240.917 kworker/u98:5/1591466 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210718750, bmval0: 1, addr: 0x7f331c207e58) 34021240.922 kworker/u98:5/1591466 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210688955, bmval0: 1, addr: 0x7f331c207ec8) 34021240.925 kworker/u98:5/1591466 nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 210688975, bmval0: 1, addr: 0x7f331c207f38)...I assume the cl_id is the client id? How can I map this to a client from /proc/fs/nfsd/clients?The hex value of 'clientid' printed from /proc/fs/nfsd/clients/XX/info is a 64-bit value composed of: typedef struct { u32 cl_boot; u32 cl_id; } clientid_t For example: clientid: 0xc8edb7f65f4a9ad cl_boot: 65f4a9add (1710533037) cl_id: c8edb7f (21068895) This should match a trace event with:nfsd:nfsd_cb_recall_any(cl_boot: 1710533037, cl_id: 21068895, bmval0: XX, addr: 0xYYYYY)If I understand it correctly, the recall_any should be called when either the system starts to experience memory pressure,yes.
/proc/locks currently has about 130k DELEG lines, so that should be a lot lower than the limit on a 192G ram server.or it reaches the delegation limits?No, this feature was added to nfsd very recently. I don't think your kernel has it.I doubt the system is actually running out of memory here as there are no other indications. Shouldn't I get those "page allocation failure" messages if it does? How can I check the number of delegations/leases currently issued,what the current maximum is and how to increase it?Max delegations is 4 per 1MB of available memory. There is no admin tool to adjust this value.
I do not recommend running a production system with delegation disabled. But for this specific issue, it might help to temporarily disable delegation to isolate problem areas.
I'm going to reboot the system with the 6.1.82 kernel (kernel-lt from elrepo). Maybe it has less new modern developments that may have introduced this.
I've been able to reproduce the situation on an additional client now that the issue happens on the server:
1. Log in on a client and mount the NFS share. 2. Open a file from the NFS share in vim so the client gets a read delegation from the server 3. Verify on the server in /proc/fs/nfsd/clients/*/states that the client has a delegation for the file 4. Forcefully reboot the client by running 'echo b > /proc/sysrq-trigger' 5. Watch the /proc/fs/nfsd/clients/*/info file on the server.The "seconds from last renew" will go up and at some point the callback state changes to "FAULT". Even when the lease delegation time (90s by default?) is over, the
seconds from last renew keeps increasing. At some point the callback state changes to "DOWN". When the client is up again and remounts the share, the mount hangs on the client
and on the server I notice there's a second directory for this client in the clients directory, even though the clientid is the same. The callback state for this new client is "UNKNOWN" and the callback address is "(einval)".
This is on a client running Fedora 39 with the 6.7.9 kernel.I don't know yet if the same procedure can be used to trigger the behavior after the server is rebooted. I'm going to try to reproduce this on another system first.
I would expect the delegations to expire automatically after 90s, but they remain in the states file of the "DOWN" client.
Regards, Rik
-DaiRegarding the recall any call: from what I've read on kernelnewbies, this feature was introduced in the 6.2 kernel? When I look at the tree for 6.1.x, it was backported in 6.1.81? Is there a way to disable this support somehow?Regards, Rik-DaiHow is the client id determined? Will changing the hostname of the client trigger a change of the client id?The nfsdclnts command for this client shows the following delegations:# nfsdclnts -f 155/states -t all Inode number | Type | Access | Deny | ip address | Filename 169346743 | open | r- | -- | 10.87.31.152:819 | disconnected dentry 169346743 | deleg | r | | 10.87.31.152:819 | disconnected dentry 169346746 | open | r- | -- | 10.87.31.152:819 | disconnected dentry 169346746 | deleg | r | | 10.87.31.152:819 | disconnected dentry I see a lot of recent patches regarding directory delegations. Could this be related to this?Will a 5.14.0-362.18.1.el9_3.0.1 kernel try to use a directory delegation?No. Directory delegations are a new feature that's still under development. They use some of the same machinery as file delegations, but they wouldn't be a factor here.The system seems to have identified that the client is no longer reachable, but the client entry does not go away. When a mount washanging on the client, there would be two directories in clients for the same client. Killing the mount command clears up the second entry.Even after running conntrack -D on the server to remove the tcpconnection from the conntrack table, the entry doesn't go away and theclient still can not mount anything from the server.A tcpdump on the client while a mount was running logged the followingmessages over and over again: request:Frame 1: 378 bytes on wire (3024 bits), 378 bytes captured (3024 bits)Ethernet II, Src: HP_19:7d:4b (e0:73:e7:19:7d:4b), Dst: ArubaaHe_f9:8e:00 (88:3a:30:f9:8e:00) Internet Protocol Version 4, Src: 10.87.31.152, Dst: 10.86.18.14Transmission Control Protocol, Src Port: 932, Dst Port: 2049, Seq: 1,Ack: 1, Len: 312 Remote Procedure Call, Type:Call XID:0x1d3220c4 Network File System [Program Version: 4] [V4 Procedure: COMPOUND (1)] GSS Data, Ops(1): CREATE_SESSION Length: 152 GSS Sequence Number: 76 Tag: <EMPTY> minorversion: 2 Operations (count: 1): CREATE_SESSION [Main Opcode: CREATE_SESSION (43)] GSS Checksum:00000028040404ffffffffff000000002c19055f1f8d442d594c13849628affc2797cbb2…GSS Token Length: 40GSS-API Generic Security Service Application Program Interfacekrb5_blob:040404ffffffffff000000002c19055f1f8d442d594c13849628affc2797cbb23fa080b0…response:Frame 2: 206 bytes on wire (1648 bits), 206 bytes captured (1648 bits)Ethernet II, Src: ArubaaHe_f9:8e:00 (88:3a:30:f9:8e:00), Dst: HP_19:7d:4b (e0:73:e7:19:7d:4b) Internet Protocol Version 4, Src: 10.86.18.14, Dst: 10.87.31.152Transmission Control Protocol, Src Port: 2049, Dst Port: 932, Seq: 1,Ack: 313, Len: 140 Remote Procedure Call, Type:Reply XID:0x1d3220c4 Network File System [Program Version: 4] [V4 Procedure: COMPOUND (1)] GSS Data, Ops(1): CREATE_SESSION(NFS4ERR_DELAY) Length: 24 GSS Sequence Number: 76 Status: NFS4ERR_DELAY (10008) Tag: <EMPTY> Operations (count: 1) [Main Opcode: CREATE_SESSION (43)] GSS Checksum:00000028040405ffffffffff000000000aa742d0798deaad1a8aa2d7c3a91bf4f6274222…GSS Token Length: 40GSS-API Generic Security Service Application Program Interfacekrb5_blob:040405ffffffffff000000000aa742d0798deaad1a8aa2d7c3a91bf4f627422226d74923…I was hoping that giving the client a different IP address would resolve the issue for this client, but it didn't. Even though theclient had a new IP address (hostname was kept the same), it failed tomount anything from the server.Changing the IP address won't help. The client is probably using thesame long-form client id as before, so the server still identifies theclient even with the address change.There are no messages in the system logs that indicate any sort of memory issue. We also increased the min_kbytes_free sysctl to 2G on the server before we restarted it with the newer kernel.Unfortunately, the cause of an NFS4ERR_DELAY error is tough to guess. The client is expected to back off and retry, so if the server keeps returning that repeatedly, then a hung mount command is expected. The question is why the server would keep returning DELAY. A lot of different problems ranging from memory allocation issues to protocolproblems can result in that error. You may want to check the NFS serverand see if anything was logged there.This is on a CREATE_SESSION call, so I wonder if the record held by the(courteous) server is somehow blocking the attempt to reestablish the session?Do you have a way to reproduce this? Since this is a centos kernel, youcould follow the page here to open a bug:Unfortunately we haven't found a reliable way to reproduce it. But we do seem to trigger it more and more lately.Regards, Rikhttps://urldefense.com/v3/__https://wiki.centos.org/ReportBugs.html__;!!ACWV5N9M2RV99hQ!LV3yWeoSOhNAkRHkxFCH2tlm0iNFVD78mxnSLyP6lrX7yBVeA2TOJ4nv6oZsqLwP4kW56CMpDWhkjjwSkWIqsboq$Not with that kernel. There are some new administrative interfaces that might allow that in the future, but they were just merged upstream andI created another dump of the workqueues and worker pools on the server:[Mon Mar 18 14:59:33 2024] Showing busy workqueues and worker pools:[Mon Mar 18 14:59:33 2024] workqueue events: flags=0x0[Mon Mar 18 14:59:33 2024] pwq 54: cpus=27 node=1 flags=0x0 nice=0active=1/256 refcnt=2 [Mon Mar 18 14:59:33 2024] pending: drm_fb_helper_damage_work [drm_kms_helper][Mon Mar 18 14:59:33 2024] workqueue events_power_efficient: flags=0x80 [Mon Mar 18 14:59:33 2024] pwq 54: cpus=27 node=1 flags=0x0 nice=0active=1/256 refcnt=2 [Mon Mar 18 14:59:33 2024] pending: fb_flashcursor [Mon Mar 18 14:59:33 2024] workqueue mm_percpu_wq: flags=0x8[Mon Mar 18 14:59:33 2024] pwq 54: cpus=27 node=1 flags=0x0 nice=0active=1/256 refcnt=3[Mon Mar 18 14:59:33 2024] pending: lru_add_drain_per_cpu BAR(362)[Mon Mar 18 14:59:33 2024] workqueue kblockd: flags=0x18[Mon Mar 18 14:59:33 2024] pwq 55: cpus=27 node=1 flags=0x0 nice=-20active=1/256 refcnt=2 [Mon Mar 18 14:59:33 2024] pending: blk_mq_timeout_workIn contrast to last time, it doesn't show anything regarding nfs thistime. I also tried the suggestion from Dai Ngo (echo 3 >/proc/sys/vm/drop_caches), but that didn't seem to make any difference.We haven't restarted the server yet as it seems the impact seems toaffect fewer clients that before. Is there anything we can run on theserver to further debug this?In the past, the issue seemed to deteriorate rapidly and resulted inissues for almost all clients after about 20 minutes. This time the impact seems to be less, but it's not gone.How can we force the NFS server to forget about a specific client? Ihaven't tried to restart the nfs service yet as I'm afraid it will fail to stop as before.aren't in that kernel. -- Jeff Layton <jlayton@xxxxxxxxxx>
-- Rik Theys System Engineer KU Leuven - Dept. Elektrotechniek (ESAT) Kasteelpark Arenberg 10 bus 2440 - B-3001 Leuven-Heverlee +32(0)16/32.11.07 ---------------------------------------------------------------- <<Any errors in spelling, tact or fact are transmission errors>>
