Nicola Ranaldo reported a segfault in a previous thread: > gfs/iscsi over 2.6.11 and gfs listener though there was no follow up on the segfault. I'm getting the same segfault when trying to umount the gfs directory. I'm running the latest cvs head from the RHEL4 branch on 2.6.9 with preemptible kernel disabled. GFS: fsid=blade_cluster:cheesefs.1: Joined cluster. Now mounting FS... GFS: fsid=blade_cluster:cheesefs.1: jid=1: Trying to acquire journal lock... GFS: fsid=blade_cluster:cheesefs.1: jid=1: Looking at journal... GFS: fsid=blade_cluster:cheesefs.1: jid=1: Done GFS: fsid=blade_cluster:cheesefs.1: Scanning for log elements... GFS: fsid=blade_cluster:cheesefs.1: Found 0 unlinked inodes GFS: fsid=blade_cluster:cheesefs.1: Found quota changes for 0 IDs GFS: fsid=blade_cluster:cheesefs.1: Done Unable to handle kernel NULL pointer dereference at virtual address 00000004 printing eip: f8c1da05 *pde = 00000000 Oops: 0000 [#1] Modules linked in: lock_dlm dlm cman gfs lock_harness dm_mod ipv6 rtc pcspkr psmouse sworks_agp agpgart tsdev mousedev joydev evdev usbhid ohci_hcd usbcore tg3 qla2300 qla2xxx scsi_transport_fc sg sr_mod sd_mod scsi_mod ide_cd cdrom reiserfs isofs ext3 jbd mbcache ide_generic via82cxxx trm290 triflex slc90e66 sis5513 siimage serverworks sc1200 rz1000 piix pdc202xx_old pdc202xx_new opti621 ns87415 hpt366 ide_disk hpt34x generic cy82c693 cs5530 cs5520 cmd64x atiixp amd74xx alim15x3 aec62xx ide_core unix CPU: 0 EIP: 0060:[<f8c1da05>] Tainted: GF VLI EFLAGS: 00010213 (2.6.9) EIP is at gfs_ail_start_trans+0x15/0x180 [gfs] eax: f8bdb5a8 ebx: 00000000 ecx: 00000400 edx: 00000000 esi: f8bc7000 edi: f8bdb5bc ebp: f667665c esp: f6747e4c ds: 007b es: 007b ss: 0068 Process umount (pid: 5117, threadinfo=f6746000 task=f650a020) Stack: f6747ec0 00000282 00000000 f6747ec0 f8bc7000 f66476b0 f6676600 f8bc7000 f8bdb5bc f6676600 f8c37945 f8bc7000 f6676600 00000000 f8bdb5a8 f8bc7000 f6746000 f6747ec0 f6bc2e00 f8c1f1b1 f8bc7000 00000400 f8bc7000 00000000 Call Trace: [<f8c37945>] gfs_ail_start+0x75/0xc0 [gfs] [<f8c1f1b1>] gfs_sync_meta+0x31/0x60 [gfs] [<f8c53be3>] gfs_make_fs_ro+0x53/0xb0 [gfs] [<f8c49e8b>] gfs_put_super+0x2cb/0x310 [gfs] [<c0154f58>] generic_shutdown_super+0xe8/0x100 [<f8c46f12>] gfs_kill_sb+0x32/0x6e [gfs] [<c0154de8>] deactivate_super+0x48/0x70 [<c0169d5f>] sys_umount+0x3f/0xa0 [<c01434ce>] do_munmap+0x11e/0x160 [<c0143560>] sys_munmap+0x50/0x80 [<c0169dd5>] sys_oldumount+0x15/0x20 [<c0105f5f>] syscall_call+0x7/0xb Code: 04 83 c4 08 e9 dd a1 54 c7 8d b6 00 00 00 00 8d bc 27 00 00 00 00 55 57 56 53 83 ec 18 8b 6c 24 30 83 c5 5c 89 f6 8b 5d 04 39 eb <8b> 7b 04 74 2e 8d b6 00 00 00 00 8b 43 c0 8d 73 c0 89 44 24 14 -dan -- -- Linux-cluster@xxxxxxxxxx http://www.redhat.com/mailman/listinfo/linux-cluster