Hello,
I want to report a Bug with NFS / FuseFS. Theres trouble with mounting a NFS FS with FuseFS, if the NFS Server is slowly responding. The problem occurs, if you mount a NFS FS with FuseFS driver for example with this command: mount -t nfs -o vers=3,nfsvers=3,hard,intr,tcp server /dest Working on this nfs overlay works like a charm, as long as the NFS Server is not under heavy load. If it gets under HEAVY load from time to time the kernel hangs (which should in my opinion never ever occur). Heres a stacktrace: [468661.923371] INFO: task sync:2828 blocked for more than 120 seconds. [468661.924202] Not tainted 4.0.0 #2 [468661.924996] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [468661.925806] sync D 0000000000000000 0 2828 26428 0x00000000 [468661.926605] ffff880036d9cb70 ffffffff8101c356 ffff8800797a2af0 ffffffff8101c3c5 [468661.927476] ffff88006312ffd8 7fffffffffffffff ffff88006312fea8 ffff880036d9cb70 [468661.928426] ffffffff811f3440 0000000000000000 ffffffff81585e5f ffff88006312feb0 [468661.929269] Call Trace: [468661.930108] [<ffffffff8101c356>] ? native_sched_clock+0x26/0x90 [468661.930975] [<ffffffff8101c3c5>] ? sched_clock+0x5/0x10 [468661.931742] [<ffffffff811f3440>] ? SyS_tee+0x390/0x390 [468661.932589] [<ffffffff81585e5f>] ? schedule+0x2f/0x80 [468661.933334] [<ffffffff81588c2a>] ? schedule_timeout+0x21a/0x290 [468661.934069] [<ffffffff81081c00>] ? insert_work+0x50/0xc0 [468661.934782] [<ffffffff81081d9b>] ? __queue_work+0x12b/0x340 [468661.935508] [<ffffffff81587270>] ? wait_for_completion+0xb0/0x120 [468661.936425] [<ffffffff810965b0>] ? wake_up_state+0x20/0x20 [468661.937107] [<ffffffff811f3440>] ? SyS_tee+0x390/0x390 [468661.937745] [<ffffffff811ec563>] ? sync_inodes_sb+0xa3/0x1c0 [468661.938432] [<ffffffff811f3440>] ? SyS_tee+0x390/0x390 [468661.939093] [<ffffffff811c6a9c>] ? iterate_supers+0xac/0x100 [468661.939737] [<ffffffff811f37a3>] ? sys_sync+0x33/0xa0 [468661.940511] [<ffffffff81589d8d>] ? system_call_fastpath+0x16/0x1b [367651.029922] INFO: task kworker/u16:1:21362 blocked for more than 120 seconds. [367651.030722] Not tainted 4.0.0 #2 [367651.031497] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [367651.032364] kworker/u16:1 D ffff88107fcd4440 0 21362 2 0x00000000 [367651.033131] Workqueue: writeback bdi_writeback_workfn (flush-0:44) [367651.033882] ffff880efccacc30 0000000000000000 ffff881038a553d0 7fffffffffffffff [367651.034619] ffff88000e317fd8 ffff88107ffaf090 ffff88102c23c1a0 0000000000000000 [367651.035440] ffff88102c23c270 00000001057745ec ffffffff81585e5f ffff880302f0a1c8 [367651.036193] Call Trace: [367651.037021] [<ffffffff81585e5f>] ? schedule+0x2f/0x80 [367651.037745] [<ffffffff811ec210>] ? inode_sleep_on_writeback+0x80/0xa0 [367651.038473] [<ffffffff810aab70>] ? wait_woken+0x90/0x90 [367651.039176] [<ffffffff811ef36a>] ? wb_writeback+0x14a/0x2c0 [367651.039881] [<ffffffff810867be>] ? set_worker_desc+0x7e/0x90 [367651.040588] [<ffffffff811efb81>] ? bdi_writeback_workfn+0x2a1/0x420 [367651.041308] [<ffffffff81083c1d>] ? process_one_work+0x14d/0x410 [367651.042035] [<ffffffff8108466b>] ? worker_thread+0x6b/0x4a0 [367651.042716] [<ffffffff81084600>] ? rescuer_thread+0x310/0x310 [367651.043428] [<ffffffff81089413>] ? kthread+0xd3/0xf0 [367651.044718] [<ffffffff81089340>] ? kthread_create_on_node+0x180/0x180 [367651.045623] [<ffffffff81589cd8>] ? ret_from_fork+0x58/0x90 [367651.046409] [<ffffffff81089340>] ? kthread_create_on_node+0x180/0x180 I tried several kernel-versions, and all of them seems to be affected by this issue. I guess the timeout occurs somewhere inside the fusefs part in the kernel. Anyways even if the NFS Server is slowly/not responding the kernel should not hang in kernel space, should it? What i verified: This issue occurs on two different servers (clients), even on two diffrent NFS servers. Heres some env. stuff: cat /proc/version Linux version 4.0.0 (root@xxx) (gcc version 4.9.2 (Debian 4.9.2-10) ) #2 SMP Wed Aug 26 21:00:33 UTC 2015 cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 62 model name : Intel(R) Xeon(R) CPU E5-1620 v2 @ 3.70GHz stepping : 4 microcode : 0x415 cpu MHz : 3700.000 cache size : 10240 KB physical id : 0 siblings : 8 core id : 0 cpu cores : 4 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid dca sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm ida arat epb pln pts dtherm tpr_shadow vnmi flexpriority ept vpid fsgsbase smep erms xsaveopt bugs : bogomips : 7399.22 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: cat /proc/modules nfsv3 40960 1 - Live 0xffffffffa0a67000 veth 16384 0 - Live 0xffffffffa07d1000 xt_nat 16384 1 - Live 0xffffffffa07cc000 xt_tcpudp 16384 129 - Live 0xffffffffa07b8000 xt_addrtype 16384 4 - Live 0xffffffffa07b3000 xt_conntrack 16384 133 - Live 0xffffffffa0a9a000 ipt_MASQUERADE 16384 4 - Live 0xffffffffa0a95000 nf_nat_masquerade_ipv4 16384 1 ipt_MASQUERADE, Live 0xffffffffa0a90000 iptable_nat 16384 1 - Live 0xffffffffa0a8b000 nf_conntrack_ipv4 20480 134 - Live 0xffffffffa0a81000 nf_defrag_ipv4 16384 1 nf_conntrack_ipv4, Live 0xffffffffa0a7c000 nf_nat_ipv4 16384 1 iptable_nat, Live 0xffffffffa087b000 iptable_filter 16384 1 - Live 0xffffffffa082c000 ip_tables 28672 2 iptable_nat,iptable_filter, Live 0xffffffffa0a74000 x_tables 28672 7 xt_nat,xt_tcpudp,xt_addrtype,xt_conntrack,ipt_MASQUERADE,iptable_filter,ip_tables, Live 0xffffffffa08c5000 nf_nat 20480 3 xt_nat,nf_nat_masquerade_ipv4,nf_nat_ipv4, Live 0xffffffffa07bd000 nf_conntrack 94208 5 xt_conntrack,nf_nat_masquerade_ipv4,nf_conntrack_ipv4,nf_nat_ipv4,nf_nat, Live 0xffffffffa0979000 bridge 102400 0 - Live 0xffffffffa08ab000 stp 16384 1 bridge, Live 0xffffffffa0778000 llc 16384 2 bridge,stp, Live 0xffffffffa076a000 nfsd 278528 2 - Live 0xffffffffa0a22000 auth_rpcgss 53248 1 nfsd, Live 0xffffffffa0993000 oid_registry 16384 1 auth_rpcgss, Live 0xffffffffa0714000 nfs_acl 16384 2 nfsv3,nfsd, Live 0xffffffffa06e2000 nfs 204800 2 nfsv3, Live 0xffffffffa09ef000 lockd 90112 3 nfsv3,nfsd,nfs, Live 0xffffffffa0962000 grace 16384 2 nfsd,lockd, Live 0xffffffffa06b0000 fscache 49152 1 nfs, Live 0xffffffffa0754000 sunrpc 270336 18 nfsv3,nfsd,auth_rpcgss,nfs_acl,nfs,lockd, Live 0xffffffffa09ac000 x86_pkg_temp_thermal 16384 0 - Live 0xffffffffa06dd000 intel_powerclamp 20480 0 - Live 0xffffffffa07d8000 coretemp 16384 0 - Live 0xffffffffa0765000 kvm_intel 151552 0 - Live 0xffffffffa0885000 kvm 425984 1 kvm_intel, Live 0xffffffffa08f9000 crct10dif_pclmul 16384 0 - Live 0xffffffffa0880000 crc32_pclmul 16384 0 - Live 0xffffffffa0773000 ghash_clmulni_intel 16384 0 - Live 0xffffffffa073e000 mgag200 40960 1 - Live 0xffffffffa09a1000 aesni_intel 167936 0 - Live 0xffffffffa08cf000 snd_pcm 90112 0 - Live 0xffffffffa0864000 aes_x86_64 20480 1 aesni_intel, Live 0xffffffffa0738000 lrw 16384 1 aesni_intel, Live 0xffffffffa074f000 gf128mul 16384 1 lrw, Live 0xffffffffa074a000 iTCO_wdt 16384 0 - Live 0xffffffffa06ca000 ttm 77824 1 mgag200, Live 0xffffffffa0850000 snd_timer 28672 1 snd_pcm, Live 0xffffffffa0730000 glue_helper 16384 1 aesni_intel, Live 0xffffffffa04cd000 iTCO_vendor_support 16384 1 iTCO_wdt, Live 0xffffffffa0831000 ablk_helper 16384 1 aesni_intel, Live 0xffffffffa07c7000 drm_kms_helper 102400 1 mgag200, Live 0xffffffffa0836000 psmouse 110592 0 - Live 0xffffffffa077d000 snd 69632 2 snd_pcm,snd_timer, Live 0xffffffffa07a1000 cryptd 20480 3 ghash_clmulni_intel,aesni_intel,ablk_helper, Live 0xffffffffa0744000 drm 274432 4 mgag200,ttm,drm_kms_helper, Live 0xffffffffa07e8000 soundcore 16384 1 snd, Live 0xffffffffa0719000 serio_raw 16384 0 - Live 0xffffffffa070f000 pcspkr 16384 0 - Live 0xffffffffa070a000 sb_edac 28672 0 - Live 0xffffffffa06fe000 edac_core 45056 1 sb_edac, Live 0xffffffffa06f2000 lpc_ich 24576 0 - Live 0xffffffffa06d2000 i2c_i801 20480 0 - Live 0xffffffffa06a4000 mei_me 20480 0 - Live 0xffffffffa06c4000 mfd_core 16384 1 lpc_ich, Live 0xffffffffa06bf000 evdev 20480 5 - Live 0xffffffffa06aa000 tpm_tis 20480 0 - Live 0xffffffffa07de000 joydev 20480 0 - Live 0xffffffffa0343000 ipmi_watchdog 24576 0 - Live 0xffffffffa079a000 mei 77824 1 mei_me, Live 0xffffffffa0e70000 tpm 32768 1 tpm_tis, Live 0xffffffffa0e67000 wmi 20480 0 - Live 0xffffffffa0e61000 processor 28672 0 - Live 0xffffffffa047c000 shpchp 32768 0 - Live 0xffffffffa06e9000 ioatdma 61440 16 - Live 0xffffffffa0720000 thermal_sys 32768 3 x86_pkg_temp_thermal,intel_powerclamp,processor, Live 0xffffffffa06b6000 button 16384 0 - Live 0xffffffffa04f5000 ipmi_si 49152 2 - Live 0xffffffffa0697000 ipmi_poweroff 16384 0 - Live 0xffffffffa0485000 ipmi_devintf 20480 0 - Live 0xffffffffa0431000 ipmi_msghandler 40960 4 ipmi_watchdog,ipmi_si,ipmi_poweroff,ipmi_devintf, Live 0xffffffffa067f000 fuse 86016 1 - Live 0xffffffffa0669000 autofs4 36864 2 - Live 0xffffffffa068d000 ext4 499712 3 - Live 0xffffffffa05ee000 crc16 16384 1 ext4, Live 0xffffffffa03fc000 jbd2 86016 1 ext4, Live 0xffffffffa05d8000 mbcache 20480 1 ext4, Live 0xffffffffa02f7000 btrfs 905216 0 - Live 0xffffffffa04fa000 ohci_hcd 45056 0 - Live 0xffffffffa04e9000 uhci_hcd 45056 0 - Live 0xffffffffa04dd000 pata_via 16384 0 - Live 0xffffffffa04d4000 netxen_nic 110592 0 - Live 0xffffffffa04b1000 3w_9xxx 45056 0 - Live 0xffffffffa04a1000 qlge 90112 0 - Live 0xffffffffa048a000 ixgbe 245760 0 - Live 0xffffffffa043f000 mdio 16384 1 ixgbe, Live 0xffffffffa03e4000 sata_nv 28672 0 - Live 0xffffffffa0437000 forcedeth 65536 0 - Live 0xffffffffa0420000 via686a 20480 0 - Live 0xffffffffa041a000 mptctl 36864 0 - Live 0xffffffffa0410000 mptsas 49152 0 - Live 0xffffffffa0403000 mptspi 24576 0 - Live 0xffffffffa03dd000 mptscsih 28672 2 mptsas,mptspi, Live 0xffffffffa02ef000 mptbase 73728 4 mptctl,mptsas,mptspi,mptscsih, Live 0xffffffffa03e9000 dm_crypt 24576 0 - Live 0xffffffffa039b000 dm_mirror 24576 0 - Live 0xffffffffa036a000 dm_region_hash 16384 1 dm_mirror, Live 0xffffffffa030a000 dm_log 20480 2 dm_mirror,dm_region_hash, Live 0xffffffffa0226000 dm_mod 94208 3 dm_crypt,dm_mirror,dm_log, Live 0xffffffffa03c5000 sata_via 20480 0 - Live 0xffffffffa0323000 ata_piix 36864 0 - Live 0xffffffffa03b7000 sata_sis 16384 0 - Live 0xffffffffa028b000 pata_sis 20480 1 sata_sis, Live 0xffffffffa0231000 sym53c8xx 81920 0 - Live 0xffffffffa03a2000 megaraid_sas 114688 0 - Live 0xffffffffa037e000 megaraid 45056 0 - Live 0xffffffffa0372000 aic7xxx 131072 0 - Live 0xffffffffa0349000 scsi_transport_spi 28672 3 mptspi,sym53c8xx,aic7xxx, Live 0xffffffffa02b1000 3w_xxxx 36864 0 - Live 0xffffffffa0339000 sky2 57344 0 - Live 0xffffffffa032a000 r8169 77824 0 - Live 0xffffffffa030f000 skge 49152 0 - Live 0xffffffffa02fd000 e1000e 212992 0 - Live 0xffffffffa02ba000 e1000 126976 0 - Live 0xffffffffa0291000 via_rhine 28672 0 - Live 0xffffffffa0283000 sis900 28672 0 - Live 0xffffffffa0277000 8139too 32768 0 - Live 0xffffffffa026e000 e100 36864 0 - Live 0xffffffffa0264000 mii 16384 5 r8169,via_rhine,sis900,8139too,e100, Live 0xffffffffa022c000 raid456 77824 1 - Live 0xffffffffa0208000 async_raid6_recov 20480 1 raid456, Live 0xffffffffa0202000 async_memcpy 16384 2 raid456,async_raid6_recov, Live 0xffffffffa01fd000 async_pq 16384 2 raid456,async_raid6_recov, Live 0xffffffffa01d6000 async_xor 16384 3 raid456,async_raid6_recov,async_pq, Live 0xffffffffa018e000 async_tx 16384 5 raid456,async_raid6_recov,async_memcpy,async_pq,async_xor, Live 0xffffffffa0105000 xor 24576 2 btrfs,async_xor, Live 0xffffffffa00fa000 raid6_pq 98304 3 btrfs,async_raid6_recov,async_pq, Live 0xffffffffa0113000 raid1 36864 1 - Live 0xffffffffa00f0000 raid0 20480 1 - Live 0xffffffffa003e000 md_mod 118784 6 raid456,raid1,raid0, Live 0xffffffffa01df000 sg 32768 0 - Live 0xffffffffa01cd000 sd_mod 40960 15 - Live 0xffffffffa0091000 hid_generic 16384 0 - Live 0xffffffffa000f000 usbhid 45056 0 - Live 0xffffffffa00e4000 hid 102400 2 hid_generic,usbhid, Live 0xffffffffa0077000 crc32c_intel 24576 1 - Live 0xffffffffa017f000 isci 122880 0 - Live 0xffffffffa01ae000 ahci 32768 0 - Live 0xffffffffa01a5000 mpt2sas 151552 12 - Live 0xffffffffa0159000 libsas 69632 1 isci, Live 0xffffffffa0193000 libahci 28672 1 ahci, Live 0xffffffffa0186000 raid_class 16384 1 mpt2sas, Live 0xffffffffa010e000 ehci_pci 16384 0 - Live 0xffffffffa002c000 ehci_hcd 73728 1 ehci_pci, Live 0xffffffffa00d1000 libata 180224 9 pata_via,sata_nv,sata_via,ata_piix,sata_sis,pata_sis,ahci,libsas,libahci, Live 0xffffffffa0237000 scsi_transport_sas 36864 4 mptsas,isci,mpt2sas,libsas, Live 0xffffffffa021c000 igb 176128 0 - Live 0xffffffffa012d000 i2c_algo_bit 16384 2 mgag200,igb, Live 0xffffffffa0025000 usbcore 196608 5 ohci_hcd,uhci_hcd,usbhid,ehci_pci,ehci_hcd, Live 0xffffffffa00a0000 scsi_mod 196608 19 3w_9xxx,mptctl,mptsas,mptspi,mptscsih,sym53c8xx,megaraid_sas,megaraid,aic7xxx,scsi_transport_spi,3w_xxxx,sg,sd_mod,isci,mpt2sas,libsas,raid_class,libata,scsi_transport_sas, Live 0xffffffffa0046000 i2c_core 49152 6 mgag200,drm_kms_helper,drm,i2c_i801,igb,i2c_algo_bit, Live 0xffffffffa0031000 usb_common 16384 1 usbcore, Live 0xffffffffa001e000 dca 16384 3 ioatdma,ixgbe,igb, Live 0xffffffffa000a000 ptp 20480 3 ixgbe,e1000e,igb, Live 0xffffffffa0014000 pps_core 20480 1 ptp, Live 0xffffffffa0000000 Greetings Sascha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
