#22 Oops when creating a file

[Greg]

I created a virgin ext4 fs on a vg composed of /dev/sda[789].

My policy file called for /gaf to be on a specific tier.

After mounting, I enabled ohsm then created a dir /mnt/gaf

Then I used dd to create test.img and got an oops.

/var/log/messages shows:

Sep 26 19:03:53 linux-mdju sudo: gaf : TTY=pts/4 ; PWD=/usr/src/ohsm_test/sample ; USER=root ; COMMAND=/bin/cp ohsm.xml /etc/ohsm/
Sep 26 19:04:11 linux-mdju sudo: gaf : TTY=pts/4 ; PWD=/usr/src/ohsm_test/sample ; USER=root ; COMMAND=/usr/bin/vi /etc/ohsm/ohsm.xml
Sep 26 19:07:11 linux-mdju sudo: gaf : TTY=pts/4 ; PWD=/usr/src/ohsm_test/sample ; USER=root ; COMMAND=/usr/local/bin/ohsm -e /etc/ohsm/ohsm.xml
Sep 26 19:07:11 linux-mdju kernel: [229953.430776] OHSM-Debug : Generic : (/usr/src/ohsm_test/kernel/admin.c, 452) : ohsm_enable:
Sep 26 19:07:11 linux-mdju kernel: [229953.430788] Request to enable OHSM.
Sep 26 19:07:11 linux-mdju kernel: [229953.430795] OHSM-Debug : Generic : (/usr/src/ohsm_test/kernel/admin.c, 454) : ohsm_enable:
Sep 26 19:07:11 linux-mdju kernel: [229953.430803] Mount Point = /mnt.
Sep 26 19:07:11 linux-mdju kernel: [229953.430832] OHSM-Debug : Generic : (/usr/src/ohsm_test/kernel/callouts.c, 57) : ohsm_set_tier:
Sep 26 19:08:03 linux-mdju kernel: [229953.430840] Setting the Home Tier = 0
Sep 26 19:09:34 linux-mdju sudo: gaf : TTY=pts/4 ; PWD=/mnt ; USER=root ; COMMAND=/usr/bin/tail /var/log/messages
Sep 26 19:10:32 linux-mdju sudo: gaf : TTY=pts/4 ; PWD=/mnt ; USER=root ; COMMAND=/bin/chown gaf .
Sep 26 19:10:38 linux-mdju kernel: [230160.482953] OHSM-Debug : Generic : (/usr/src/ohsm_test/kernel/callouts.c, 295) : ohsm_ext4_mkdir:
Sep 26 19:10:38 linux-mdju kernel: [230160.482964] Try to get the tier for directoty /gaf
Sep 26 19:10:38 linux-mdju kernel: [230160.482972] OHSM-Debug : Generic : (/usr/src/ohsm_test/kernel/callouts.c, 319) : ohsm_ext4_mkdir:
Sep 26 19:10:38 linux-mdju kernel: [230160.482980] Home Tier = 1
Sep 26 19:10:38 linux-mdju kernel: [230160.482987] OHSM-Debug : Generic : (/usr/src/ohsm_test/kernel/callouts.c, 57) : ohsm_set_tier:
Sep 26 19:10:59 linux-mdju kernel: [230160.482995] Setting the Home Tier = 1
Sep 26 19:12:07 linux-mdju kernel: [230249.209838] OHSM-Debug : Generic : (/usr/src/ohsm_test/kernel/callouts.c, 185) : ohsm_ext4_create:
Sep 26 19:12:07 linux-mdju kernel: [230249.209849] Processing test.img
Sep 26 19:12:07 linux-mdju kernel: [230249.209856] OHSM-Debug : Generic : (/usr/src/ohsm_test/kernel/callouts.c, 198) : ohsm_ext4_create:
Sep 26 19:12:07 linux-mdju kernel: [230249.209863] Trying to find TIER based on fname
Sep 26 19:12:07 linux-mdju kernel: [230249.209872] OHSM-Debug : Generic : (/usr/src/ohsm_test/kernel/callouts.c, 205) : ohsm_ext4_create:
Sep 26 19:12:07 linux-mdju kernel: [230249.209879] Trying to find TIER based on UID
Sep 26 19:12:07 linux-mdju kernel: [230249.209886] OHSM-Debug : Generic : (/usr/src/ohsm_test/kernel/callouts.c, 213) : ohsm_ext4_create:
Sep 26 19:12:07 linux-mdju kernel: [230249.209893] Trying to find TIER based on GID
Sep 26 19:12:07 linux-mdju kernel: [230249.209946] BUG: unable to handle kernel NULL pointer dereference at 0000009c
Sep 26 19:12:07 linux-mdju kernel: [230249.210003] IP: [<f8b5fdc2>] ohsm_set_tier+0x22/0x270 [ohsm]
Sep 26 19:12:07 linux-mdju kernel: [230249.210048] *pde = 00000000
Sep 26 19:12:07 linux-mdju kernel: [230249.210077] Oops: 0000 [#1] SMP
Sep 26 19:12:07 linux-mdju kernel: [230249.210108] last sysfs file: /sys/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1/energy_full
Sep 26 19:12:07 linux-mdju kernel: [230249.210143] Modules linked in: ohsm ext4 jbd2 crc16 st ide_gd_mod ide_cd_mod ide_core joydev ip6t_LOG xt_tcpudp xt_pkttype ipt_LOG xt_limit snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device edd af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq speedstep_lib ip6t_REJECT nf_conntrack_ipv6 ip6table_raw xt_NOTRACK ipt_REJECT xt_state iptable_raw iptable_filter ip6table_mangle nf_conntrack_netbios_ns nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4 ip_tables ip6table_filter ip6_tables x_tables ipv6 fuse loop dm_mod arc4 ecb cryptomgr aead pcompress crypto_blkcipher crypto_hash crypto_algapi b43 mac80211 cfg80211 led_class snd_intel8x0 snd_intel8x0m snd_ac97_codec ac97_bus snd_pcm ssb ohci1394 yenta_socket snd_timer smsc_ircc2 iTCO_wdt pcmcia rsrc_nonstatic snd soundcore irda iTCO_vendor_support sr_mod ieee1394 e100 pcmcia_core video toshiba_acpi snd_page_alloc pcspkr crc_ccitt cdrom sg output shpchp rfkill pci_hotplug intel_agp ac button battery usbhid hid
Sep 26 19:12:07 linux-mdju kernel: ata_generic ata_piix ahci rtc_cmos uhci_hcd libata ehci_hcd rtc_core rtc_lib fan thermal processor thermal_sys hwmon [last unloaded: ohsm]
Sep 26 19:12:07 linux-mdju kernel: [230249.210596]
Sep 26 19:12:07 linux-mdju kernel: [230249.210626] Pid: 30243, comm: dd Tainted: G W (2.6.31-rc9-ohsm-7-default #1) Satellite 5105
Sep 26 19:12:07 linux-mdju kernel: [230249.210661] EIP: 0060:[<f8b5fdc2>] EFLAGS: 00010246 CPU: 0
Sep 26 19:12:07 linux-mdju kernel: [230249.210696] EIP is at ohsm_set_tier+0x22/0x270 [ohsm]
Sep 26 19:12:07 linux-mdju kernel: [230249.210726] EAX: 00000000 EBX: f6af8090 ECX: 00000000 EDX: 00000000
Sep 26 19:12:07 linux-mdju kernel: [230249.210758] ESI: f6af8090 EDI: 000003e8 EBP: ee89ae1c ESP: ee89adf0
Sep 26 19:12:07 linux-mdju kernel: [230249.210790] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Sep 26 19:12:07 linux-mdju kernel: [230249.210822] Process dd (pid: 30243, ti=ee89a000 task=e52dd2d0 task.ti=ee89a000)
Sep 26 19:12:07 linux-mdju kernel: [230249.210853] Stack:
Sep 26 19:12:07 linux-mdju kernel: [230249.210877] ee89ae41 c952c34e c952c34e f6af8090 ebbc0000 000003e8 ee89ae00 c952c34e
Sep 26 19:12:07 linux-mdju kernel: [230249.210904] <0> f6af8090 00000064 000003e8 ee89be4c f8b6037b f8b60fcc f8b62574 f8b60e48
Sep 26 19:12:07 linux-mdju kernel: [230249.210952] <0> 000000d5 f8b60b3f ebbc001c 74736574 676d692e 00000000 00000003 00000003
Sep 26 19:12:07 linux-mdju kernel: [230249.211019] Call Trace:
Sep 26 19:12:07 linux-mdju kernel: [230249.211088] [<f8b6037b>] ohsm_ext4_create+0xcb/0x310 [ohsm]
Sep 26 19:12:07 linux-mdju kernel: [230249.211164] [<f8abe648>] ext4_create+0x118/0x170 [ext4]
Sep 26 19:12:07 linux-mdju kernel: [230249.211230] [<c03150ee>] vfs_create+0xde/0x150
Sep 26 19:12:07 linux-mdju kernel: [230249.211272] [<c031815c>] do_filp_open+0x88c/0x990
Sep 26 19:12:07 linux-mdju kernel: [230249.211317] [<c03074dd>] do_sys_open+0x5d/0x130
Sep 26 19:12:07 linux-mdju kernel: [230249.211356] [<c0307644>] sys_open+0x34/0x60
Sep 26 19:12:07 linux-mdju kernel: [230249.211395] [<c0203edb>] sysenter_do_call+0x12/0x28
Sep 26 19:12:07 linux-mdju kernel: [230249.211442] [<ffffe424>] 0xffffe424
Sep 26 19:12:07 linux-mdju kernel: [230249.211469] Code: 76 00 8d bc 27 00 00 00 00 55 89 e5 83 ec 2c 89 75 f8 89 c6 65 a1 14 00 00 00 89 45 f0 31 c0 89 5d f4 89 7d fc 88 55 ec 8b 46 10 <8b> 80 9c 00 00 00 85 c0 0f 84 30 01 00 00 8b 58 48 85 db 0f 84
Sep 26 19:12:07 linux-mdju kernel: [230249.211641] EIP: [<f8b5fdc2>] ohsm_set_tier+0x22/0x270 [ohsm] SS:ESP 0068:ee89adf0
Sep 26 19:12:07 linux-mdju kernel: [230249.211683] CR2: 000000000000009c
Sep 26 19:12:07 linux-mdju kernel: [230249.211713] ---[ end trace a7919e7f17c0a727 ]---

[Greg]

I then tried to just create a file via "> it" and the system locked up.

[Manish Katiyar]

Greg,

Isn't this bug 2861275 . This should have been fixed by commit ce112dba5e04ccff2b66619a8a9922e41ba3c894 in ohsm_next . Can you please check if you have the changes.

[Sandeepksinha]

Looks like this has been fixed for sure. But I am surprised to see that the system locked up.... Greg, I am having a look at the issue and trying to perform rigorous testing of the code.

[Sandeepksinha]

Issue is fixed... closing the BUG.
I have tested the current code its working fine.