Thanks a lot for your explaination, Mike.
In my orginal problem, a logout was issued manually after login. At the time of this command was issued, kernel oops happened.
For the new test, it failed int the same place (in
spi_device_match). I cannot track the time when logout was issued, but I suspect it was the same time when kernel oops happened. Below is the kernel log in my new test.
-Kevin
Oct 24 14:00:48 qye-cms kernel: [184273.268108] scsi55415 : iSCSI Initiator over TCP/IP
Oct 24 14:00:48 qye-cms kernel: [184273.523222] scsi 55415:0:0:91: Direct-Access IET VIRTUAL-DISK 0 PQ: 0 ANSI: 4
Oct 24 14:00:48 qye-cms kernel: [184273.528678] sd 55415:0:0:91: [sdb] 1024000 512-byte hardware sectors (524 MB)
Oct 24 14:00:48 qye-cms kernel: [184273.529105] sd 55415:0:0:91: [sdb] Write Protect is off
Oct 24 14:00:48 qye-cms kernel: [184273.529109] sd 55415:0:0:91: [sdb] Mode Sense: 77 00 00 08
Oct 24 14:00:48 qye-cms kernel: [184273.529545] sd 55415:0:0:91: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
Oct 24 14:00:48 qye-cms kernel: [184273.530040] sd 55415:0:0:91: [sdb] 1024000 512-byte hardware sectors (524 MB)
Oct 24 14:00:48 qye-cms kernel: [184273.531361] sd 55415:0:0:91: [sdb] Write Protect is off
Oct 24 14:00:48 qye-cms kernel: [184273.531367] sd 55415:0:0:91: [sdb] Mode Sense: 77 00 00 08
Oct 24 14:00:48 qye-cms kernel: [184273.533646] sd 55415:0:0:91: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
Oct 24 14:01:08 qye-cms kernel: [184273.533654] sdb:<3> connection55413:0: ping timeout of 15 secs expired, last rx 46079163, last ping 46080413, now 46084163
Oct 24 14:01:08 qye-cms kernel: [184293.496601] connection55413:0: detected conn error (1011)
Oct 24 14:03:08 qye-cms kernel: [184413.530473] session55413: session recovery timed out after 120 secs
Oct 24 14:03:08 qye-cms kernel: [184413.534610] sd 55415:0:0:91: [sdb] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK,SUGGEST_OK
Oct 24 14:03:08 qye-cms kernel: [184413.534697] end_request: I/O error, dev sdb, sector 8
Oct 24 14:03:08 qye-cms kernel: [184413.534804] Buffer I/O error on device sdb, logical block 1
Oct 24 14:03:08 qye-cms kernel: [184413.535039] sd 55415:0:0:91: [sdb] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK,SUGGEST_OK
Oct 24 14:03:08 qye-cms kernel: [184413.535044] end_request: I/O error, dev sdb, sector 8
Oct 24 14:03:08 qye-cms kernel: [184413.535053] Buffer I/O error on device sdb, logical block 1
Oct 24 14:03:08 qye-cms kernel: [184413.535163] Dev sdb: unable to read RDB block 8
Oct 24 14:03:08 qye-cms kernel: [184413.537038] sd 55415:0:0:91: [sdb] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK,SUGGEST_OK
Oct 24 14:03:08 qye-cms kernel: [184413.537048] end_request: I/O error, dev sdb, sector 24
Oct 24 14:03:08 qye-cms kernel: [184413.537057] Buffer I/O error on device sdb, logical block 3
Oct 24 14:03:08 qye-cms kernel: [184413.537185] sd 55415:0:0:91: [sdb] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK,SUGGEST_OK
Oct 24 14:03:08 qye-cms kernel: [184413.537189] end_request: I/O error, dev sdb, sector 24
Oct 24 14:03:08 qye-cms kernel: [184413.537192] Buffer I/O error on device sdb, logical block 3
Oct 24 14:03:08 qye-cms kernel: [184413.537326] unable to read partition table
Oct 24 14:03:08 qye-cms kernel: [184413.537398] sd 55415:0:0:91: [sdb] Attached SCSI disk
Oct 24 14:03:08 qye-cms kernel: [184413.537478] sd 55415:0:0:91: Attached scsi generic sg1 type 0
Oct 24 14:05:03 qye-cms kernel: [184413.597688] BUG: unable to handle kernel NULL pointer dereference at virtual address 00000060
Oct 24 14:05:03 qye-cms kernel: [184413.684629] printing eip: e08a212a *pde = 00000000
Oct 24 14:05:03 qye-cms kernel: [184413.684907] Oops: 0000 [#1] SMP
Oct 24 14:05:03 qye-cms kernel: [184413.685202] Modules linked in: iscsi_trgt crc32c libcrc32c vmblock vmmemctl cpufreq_conservative cpufreq_ondemand cpufreq_userspace cpufreq_stats freq_table cpufreq_powersave sbs video output sbshc dock battery iptable_filter ip_tables x_tables vmhgfs iscsi_tcp libiscsi scsi_transport_iscsi lp loop ipv6 parport_pc parport evdev container serio_raw psmouse ac button i2c_piix4 intel_agp i2c_core pcspkr agpgart shpchp pci_hotplug ext3 jbd mbcache sg sd_mod floppy pcnet32 mptspi mptscsih mptbase mii pata_acpi ata_generic scsi_transport_spi ata_piix libata scsi_mod raid10 raid456 async_xor async_memcpy async_tx xor raid1 raid0 multipath linear md_mod dm_mirror dm_snapshot dm_mod thermal processor fan fbcon tileblit font bitblit softcursor fuse vmxnet
Oct 24 14:05:03 qye-cms kernel: [184413.686686]
Oct 24 14:05:03 qye-cms kernel: [184413.686773] Pid: 3770, comm: iscsid Not tainted (2.6.24-24-generic #1)
Oct 24 14:05:03 qye-cms kernel: [184413.686850] EIP: 0060:[<e08a212a>] EFLAGS: 00010202 CPU: 0
Oct 24 14:05:03 qye-cms kernel: [184413.725583] EIP is at spi_device_match+0x1a/0x60 [scsi_transport_spi]
Oct 24 14:05:03 qye-cms kernel: [184413.725680] EAX: 00000000 EBX: df1c0cb0 ECX: df1c0c00 EDX: df1c0cb0
Oct 24 14:05:03 qye-cms kernel: [184413.725766] ESI: df1c0cb0 EDI: dfbd8a00 EBP: c0286000 ESP: deaf3b8c
Oct 24 14:05:03 qye-cms kernel: [184413.727201] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Oct 24 14:05:03 qye-cms kernel: [184413.727287] Process iscsid (pid: 3770, ti=deaf2000 task=dda1e5c0 task.ti=deaf2000)
Oct 24 14:05:03 qye-cms kernel: [184413.727370] Stack: e08a7c90 c0285c8f e095e328 df1c0dd8 de1ee030 df1c0c00 df1c0cb0 dfbd8a00
Oct 24 14:05:03 qye-cms kernel: [184413.727532] 00000202 e09449cd df1c0c00 de1ee030 e0944a2f df1c0c00 de1ee000 e0944acc
Oct 24 14:05:03 qye-cms kernel: [184413.727650] dfbd8a14 de1ee8a4 e0944b50 00000000 e0944b64 00000000 c02805c2 de1ee8a4
Oct 24 14:05:03 qye-cms kernel: [184413.727770] Call Trace:
Oct 24 14:05:03 qye-cms kernel: [184413.727961] [<c0285c8f>] attribute_container_device_trigger+0x4f/0xb0
Oct 24 14:05:03 qye-cms kernel: [184413.728262] [<e09449cd>] __scsi_remove_device+0x3d/0x80 [scsi_mod]
Oct 24 14:05:03 qye-cms kernel: [184413.747281] [<e0944a2f>] scsi_remove_device+0x1f/0x30 [scsi_mod]
Oct 24 14:05:03 qye-cms kernel: [184413.747364] [<e0944acc>] __scsi_remove_target+0x8c/0xc0 [scsi_mod]
Oct 24 14:05:03 qye-cms kernel: [184413.747443] [<e0944b50>] __remove_child+0x0/0x20 [scsi_mod]
Oct 24 14:05:03 qye-cms kernel: [184413.747523] [<e0944b64>] __remove_child+0x14/0x20 [scsi_mod]
Oct 24 14:05:03 qye-cms kernel: [184413.747599] [<c02805c2>] device_for_each_child+0x22/0x40
Oct 24 14:05:03 qye-cms kernel: [184413.747684] [<e0944b3e>] scsi_remove_target+0x3e/0x50 [scsi_mod]
Oct 24 14:05:03 qye-cms kernel: [184413.747766] [<e0a9185c>] __iscsi_unbind_session+0x6c/0xa0 [scsi_transport_iscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.747910] [<e0a91948>] iscsi_remove_session+0xb8/0x120 [scsi_transport_iscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.748020] [<e0a9bac6>] iscsi_session_teardown+0x26/0x80 [libiscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.804030] [<e0a9baa0>] iscsi_session_teardown+0x0/0x80 [libiscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.804104] [<e0a919b8>] iscsi_destroy_session+0x8/0x20 [scsi_transport_iscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.804217] [<e0a9bb05>] iscsi_session_teardown+0x65/0x80 [libiscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.804291] [<e0a9baa0>] iscsi_session_teardown+0x0/0x80 [libiscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.804362] [<e0a90030>] iscsi_iter_session_fn+0x0/0x30 [scsi_transport_iscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.804484] [<e0a9004f>] iscsi_iter_session_fn+0x1f/0x30 [scsi_transport_iscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.804596] [<c02805c2>] device_for_each_child+0x22/0x40
Oct 24 14:05:03 qye-cms kernel: [184413.804667] [<e0a906f0>] iscsi_if_rx+0x0/0x860 [scsi_transport_iscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.804740] [<e0a9bb2d>] iscsi_host_remove+0xd/0x20 [libiscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.804813] [<e0aa6324>] iscsi_tcp_session_destroy+0x34/0x50 [iscsi_tcp]
Oct 24 14:05:03 qye-cms kernel: [184413.804935] [<e0a90ec4>] iscsi_if_rx+0x7d4/0x860 [scsi_transport_iscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.805011] [<c018d13d>] __slab_free+0x16d/0x2a0
Oct 24 14:05:03 qye-cms kernel: [184413.805133] [<e0a90714>] iscsi_if_rx+0x24/0x860 [scsi_transport_iscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.805204] [<c02a3a98>] __kfree_skb+0x8/0x80
Oct 24 14:05:03 qye-cms kernel: [184413.805299] [<e0a906f0>] iscsi_if_rx+0x0/0x860 [scsi_transport_iscsi]
Oct 24 14:05:03 qye-cms kernel: [184413.805380] [<c02c282d>] netlink_unicast+0x1dd/0x210
Oct 24 14:05:03 qye-cms kernel: [184413.805457] [<c021aeee>] copy_from_user+0x2e/0x70
Oct 24 14:05:03 qye-cms kernel: [184413.805574] [<c02c30a6>] netlink_sendmsg+0x226/0x2f0
Oct 24 14:05:03 qye-cms kernel: [184413.805644] [<c029dc51>] sock_sendmsg+0x111/0x130
Oct 24 14:05:03 qye-cms kernel: [184413.805709] [<c0140c20>] autoremove_wake_function+0x0/0x40
Oct 24 14:05:03 qye-cms kernel: [184413.805807] [<c0140000>] sys_timer_create+0x2c0/0x330
Oct 24 14:05:03 qye-cms kernel: [184413.805885] [<c0199457>] do_lookup+0x67/0x1c0
Oct 24 14:05:03 qye-cms kernel: [184413.805967] [<c019b87b>] __link_path_walk+0xaab/0xe10
Oct 24 14:05:03 qye-cms kernel: [184413.806034] [<c021aeee>] copy_from_user+0x2e/0x70
Oct 24 14:05:03 qye-cms kernel: [184413.806097] [<c021aeee>] copy_from_user+0x2e/0x70
Oct 24 14:05:03 qye-cms kernel: [184413.806160] [<c029ddc9>] sys_sendmsg+0x159/0x270
Oct 24 14:05:03 qye-cms kernel: [184413.806225] [<c029ec4d>] sys_recvmsg+0x17d/0x230
Oct 24 14:05:03 qye-cms kernel: [184413.806289] [<c01a2ffd>] d_kill+0x3d/0x60
Oct 24 14:05:03 qye-cms kernel: [184413.806378] [<c01a2ffd>] d_kill+0x3d/0x60
Oct 24 14:05:03 qye-cms kernel: [184413.806440] [<c019abca>] getname+0xaa/0xe0
Oct 24 14:05:03 qye-cms kernel: [184413.806498] [<c021b170>] copy_to_user+0x30/0x60
Oct 24 14:05:03 qye-cms kernel: [184413.806559] [<c0194f59>] cp_new_stat64+0xf9/0x110
Oct 24 14:05:03 qye-cms kernel: [184413.806628] [<c029f334>] sys_socketcall+0xb4/0x2b0
Oct 24 14:05:03 qye-cms kernel: [184413.806695] [<c01043b2>] sysenter_past_esp+0x6b/0xa9
Oct 24 14:05:03 qye-cms kernel: [184413.806840] =======================
Oct 24 14:05:03 qye-cms kernel: [184413.806908] Code: 08 88 50 07 b8 08 00 00 00 c3 8d b4 26 00 00 00 00 53 89 d0 89 d3 e8 b6 1b 0a 00 85 c0 74 1c 8b 83 50 ff ff ff 8d 8b 50 ff ff ff <8b> 40 60 85 c0 74 09 81 78 1c c0 7c 8a e0 74 06 31 c0 5b c3 66
Oct 24 14:05:03 qye-cms kernel: [184413.807225] EIP: [<e08a212a>] spi_device_match+0x1a/0x60 [scsi_transport_spi] SS:ESP 0068:deaf3b8c
Oct 24 14:05:03 qye-cms kernel: [184413.807764] ---[ end trace 756dbf4d8889f5b8 ]---
Oct 24 14:05:03 qye-cms kernel: [184413.851184] sd 55415:0:0:91: [sdb] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK,SUGGEST_OK
Oct 24 14:05:03 qye-cms kernel: [184413.851329] end_request: I/O error, dev sdb, sector 0
Oct 24 14:05:03 qye-cms kernel: [184413.851395] Buffer I/O error on device sdb, logical block 0
Oct 24 14:05:03 qye-cms kernel: [184413.851465] Buffer I/O error on device sdb, logical block 1
Oct 24 14:05:03 qye-cms kernel: [184413.851531] Buffer I/O error on device sdb, logical block 2
Oct 24 14:05:03 qye-cms kernel: [184413.851597] Buffer I/O error on device sdb, logical block 3
Oct 24 14:05:03 qye-cms kernel: [184413.851718] sd 55415:0:0:91: [sdb] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK,SUGGEST_OK
Oct 24 14:05:03 qye-cms kernel: [184413.851845] end_request: I/O error, dev sdb, sector 0
Oct 24 14:05:03 qye-cms kernel: [184413.851909] Buffer I/O error on device sdb, logical block 0