With kernel 3.10-rcX there's a big likelihood to observe that issue if I do the following steps: 1. create a 257 MB file /mnt/ramdisk/disk0 2. create an EXT4 fs onto it 3. mount it onto /mnt/ramdisk/victims/ 4. create files and directories in /mnt/ramdisk/victims/v1/v2 5. exportfs the directory /mnt/ramdisk/victims/ via NFS 6. start a user mode linux 7. within UML nfs-mount the exported directory /mnt/ramdisk/victims/ onto 3 different UML directories /mnt/nfsv[234] - just to test all 3 NFS versions 8. run trinity within the UML guest using a victims directory /mnt/nfsv[234]/v1/v2 for a longer period (rather hours) 9. stop UML, Ctrl-C any running trinity / UML process 10. try to umount mnt/ramdisk/victims/ 11. if that attempt fails stop the nfs service and run the umount command again - it segfaults now 12. if the 1st umount is however successfully then make a :-/ 2013-05-30T19:20:28.000+02:00 n22 rpc.mountd[2921]: authenticated unmount request from 192.168.1.63:798 for /mnt/ramdisk/victims (/mnt/ramdisk/victims) 2013-05-30T19:20:28.000+02:00 n22 rpc.mountd[2921]: authenticated unmount request from 192.168.1.63:799 for /mnt/ramdisk/victims (/mnt/ramdisk/victims) 2013-05-30T19:20:42.569+02:00 n22 kernel: br0: port 1(tap0) entered disabled state 2013-05-30T19:21:10.000+02:00 n22 rpc.mountd[2921]: Caught signal 15, un-registering and exiting. 2013-05-30T19:21:10.336+02:00 n22 kernel: lockd: couldn't shutdown host module for net c161c200! 2013-05-30T19:21:10.338+02:00 n22 kernel: nfsd: last server has exited, flushing export cache 2013-05-30T19:21:12.227+02:00 n22 kernel: EXT4-fs (loop0): sb orphan head is 32315 2013-05-30T19:21:12.227+02:00 n22 kernel: sb_info orphan list: 2013-05-30T19:21:12.227+02:00 n22 kernel: inode loop0:32315 at e8702158: mode 102357, nlink 0, next 32173 2013-05-30T19:21:12.227+02:00 n22 kernel: inode loop0:32173 at e773a860: mode 100406, nlink 0, next 32383 2013-05-30T19:21:12.227+02:00 n22 kernel: inode loop0:32383 at e93bbd78: mode 102041, nlink 0, next 32233 2013-05-30T19:21:12.227+02:00 n22 kernel: inode loop0:32233 at e7e742e0: mode 103267, nlink 0, next 32421 2013-05-30T19:21:12.227+02:00 n22 kernel: inode loop0:32421 at e84fad10: mode 100102, nlink 0, next 32155 2013-05-30T19:21:12.227+02:00 n22 kernel: inode loop0:32155 at e8700538: mode 100700, nlink 0, next 32230 2013-05-30T19:21:12.227+02:00 n22 kernel: inode loop0:32230 at e77397f8: mode 102747, nlink 0, next 32313 2013-05-30T19:21:12.227+02:00 n22 kernel: inode loop0:32313 at e8701ca8: mode 102667, nlink 0, next 32244 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32244 at e79b3670: mode 100353, nlink 0, next 32361 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32361 at e8703b20: mode 100206, nlink 0, next 32271 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32271 at e79b3b20: mode 100000, nlink 0, next 32255 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32255 at eb8ec088: mode 104657, nlink 0, next 32366 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32366 at e8701f00: mode 105711, nlink 0, next 32281 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32281 at e77382e0: mode 101637, nlink 0, next 32151 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32151 at e92cce98: mode 101557, nlink 0, next 32138 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32138 at e932a608: mode 101327, nlink 0, next 32013 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32013 at e74be158: mode 101527, nlink 0, next 32012 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32012 at e74be3b0: mode 102427, nlink 0, next 32110 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32110 at e74bdf00: mode 101303, nlink 0, next 32112 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32112 at e74beab8: mode 100000, nlink 0, next 32066 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32066 at e79f9a50: mode 104607, nlink 0, next 32148 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32148 at e9331ca8: mode 102507, nlink 0, next 32158 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32158 at e84c31c0: mode 100000, nlink 0, next 32139 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32139 at e84c1ca8: mode 101507, nlink 0, next 32115 2013-05-30T19:21:12.228+02:00 n22 kernel: inode loop0:32115 at e93310f0: mode 104037, nlink 0, next 0 2013-05-30T19:21:12.228+02:00 n22 kernel: ------------[ cut here ]------------ 2013-05-30T19:21:12.228+02:00 n22 kernel: kernel BUG at fs/ext4/super.c:804! 2013-05-30T19:21:12.228+02:00 n22 kernel: invalid opcode: 0000 [#1] SMP 2013-05-30T19:21:12.228+02:00 n22 kernel: Modules linked in: loop nfsd auth_rpcgss oid_registry lockd sunrpc ip6t_REJECT ip6table_filter ip6_tables ipt_MASQUERADE xt_owner xt_LOG xt_limit xt_multiport ipt_REJECT xt_tcpudp xt_recent xt_conntrack iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_filter ip_tables x_tables af_packet pppoe pppox ppp_generic slhc bridge stp llc ipv6 tun fuse dm_mod coretemp kvm_intel kvm aesni_intel i915 xts aes_i586 lrw gf128mul ablk_helper arc4 hid_cherry hid_generic iwldvm fbcon snd_hda_codec_conexant cfbfillrect cfbimgblt cryptd i2c_algo_bit sr_mod cfbcopyarea intel_agp sdhci_pci cdrom intel_gtt evdev mac80211 sdhci bitblit mmc_core softcursor font acpi_cpufreq mperf psmouse usbhid drm_kms_helper usblp snd_hda_intel e1000e uvcvideo drm videobuf2_vmalloc hid agpgart videobuf2_memops videobuf2_core videodev fb 8250_pci snd_hda_codec ptp i2c_i801 8250 pps_core processor battery fbdev iwlwifi i2c_core cfg80211 thermal wmi tpm_tis snd_pcm snd_page_alloc snd_timer tpm tpm_bios thinkpad_acpi video nvram snd soundcore ac rfkill thermal_sys button serial_core hwmon [last unloaded: microcode] 2013-05-30T19:21:12.228+02:00 n22 kernel: CPU: 1 PID: 11831 Comm: umount Not tainted 3.10.0-rc3+ #6 2013-05-30T19:21:12.228+02:00 n22 kernel: Hardware name: LENOVO 4180F65/4180F65, BIOS 83ET73WW (1.43 ) 11/30/2012 2013-05-30T19:21:12.228+02:00 n22 kernel: task: eec69aa0 ti: eb4b6000 task.ti: eb4b6000 2013-05-30T19:21:12.228+02:00 n22 kernel: EIP: 0060:[<c11ba6ec>] EFLAGS: 00010287 CPU: 1 2013-05-30T19:21:12.228+02:00 n22 kernel: EIP is at ext4_put_super+0x2dc/0x2e0 2013-05-30T19:21:12.228+02:00 n22 kernel: EAX: 0000003d EBX: eaa3d400 ECX: eaa3d550 EDX: eaa3d550 2013-05-30T19:21:12.228+02:00 n22 kernel: ESI: eaa3f000 EDI: eaa3d514 EBP: eb4b7efc ESP: eb4b7ecc 2013-05-30T19:21:12.228+02:00 n22 kernel: DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 2013-05-30T19:21:12.228+02:00 n22 kernel: CR0: 80050033 CR2: b6bab000 CR3: 2edc6000 CR4: 000407f0 2013-05-30T19:21:12.229+02:00 n22 kernel: DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 2013-05-30T19:21:12.229+02:00 n22 kernel: DR6: ffff0ff0 DR7: 00000400 2013-05-30T19:21:12.229+02:00 n22 kernel: Stack: 2013-05-30T19:21:12.229+02:00 n22 kernel: c1567fa0 eaa3f1bc 00007d73 e93310f0 0000881f 00000000 00000000 e93310d0 2013-05-30T19:21:12.229+02:00 n22 kernel: eaa3d550 eaa3f000 eaa3f058 c14a06e0 eb4b7f18 c111f771 eb4b7f28 eb4b7f18 2013-05-30T19:21:12.229+02:00 n22 kernel: f1d70400 00000083 eaa3f000 eb4b7f28 c111f819 eaa3f000 c15fde28 eb4b7f38 2013-05-30T19:21:12.229+02:00 n22 kernel: Call Trace: 2013-05-30T19:21:12.229+02:00 n22 kernel: [<c111f771>] generic_shutdown_super+0x51/0xd0 2013-05-30T19:21:12.229+02:00 n22 kernel: [<c111f819>] kill_block_super+0x29/0x70 2013-05-30T19:21:12.229+02:00 n22 kernel: [<c111fa64>] deactivate_locked_super+0x44/0x70 2013-05-30T19:21:12.229+02:00 n22 kernel: [<c1120437>] deactivate_super+0x47/0x60 2013-05-30T19:21:12.229+02:00 n22 kernel: [<c11371bd>] mntput_no_expire+0xcd/0x120 2013-05-30T19:21:12.229+02:00 n22 kernel: [<c113807e>] SyS_umount+0xae/0x330 2013-05-30T19:21:12.229+02:00 n22 kernel: [<c113831e>] SyS_oldumount+0x1e/0x20 2013-05-30T19:21:12.229+02:00 n22 kernel: [<c1482701>] sysenter_do_call+0x12/0x22 2013-05-30T19:21:12.229+02:00 n22 kernel: Code: 24 a0 7f 56 c1 05 bc 01 00 00 89 44 24 04 e8 d2 f8 2b 00 8b 4d ec 8b 55 f0 8b 09 39 ca 75 b2 39 93 50 01 00 00 0f 84 9a fe ff ff <0f> 0b 66 90 55 89 e5 83 ec 20 66 66 66 66 90 8d 45 18 c7 04 24 2013-05-30T19:21:12.229+02:00 n22 kernel: EIP: [<c11ba6ec>] ext4_put_super+0x2dc/0x2e0 SS:ESP 0068:eb4b7ecc 2013-05-30T19:21:12.229+02:00 n22 kernel: ---[ end trace 2a52a524ae176def ]--- -- MfG/Sincerely Toralf Förster pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html