zfs deadlock
krichy at cflinux.hu
krichy at cflinux.hu
Fri Dec 6 15:55:01 UTC 2013
Dear Steven,
Of course. But I got further now. You mentioned that is normal that zfs
send umounts snapshots. I dont know, but this indeed causes a problem:
It is also reproducible without zfs send.
1. Have a large directory structure (just to make sure find runs long
enough), make a snapshot of it.
# cd /mnt/pool/set/.zfs/snapshot/snap
# find .
meanwhile, on another console
# umount -f /mnt/pool/set/.zfs/snapshot/snap
will cause a panic, or such.
So effectively a regular user on a system can cause a crash.
Regards,
2013-12-06 16:50 időpontban Steven Hartland ezt írta:
> kernel compiled, installed and rebooted?
> ----- Original Message ----- From: <krichy at cflinux.hu>
> To: <smh at FreeBSD.org>
> Sent: Friday, December 06, 2013 12:17 PM
> Subject: Fwd: Re: zfs deadlock
>
>
>> Dear shm,
>>
>> I've applied r258294 on top fo releng/9.2, but my test seems to
>> trigger
>> the deadlock again.
>>
>> Regards,
>>
>> -------- Eredeti üzenet --------
>> Tárgy: Re: zfs deadlock
>> Dátum: 2013-12-06 13:17
>> Feladó: krichy at cflinux.hu
>> Címzett: freebsd-fs at freebsd.org
>>
>> I've applied r258294 on top of releng/9.2, and using the attached
>> scripts parallel, the system got into a deadlock again.
>>
>> 2013-12-06 11:35 időpontban Steven Hartland ezt írta:
>>> Thats correct it unmounts the mounted snapshot.
>>>
>>> Regards
>>> Steve
>>>
>>> ----- Original Message ----- From: <krichy at cflinux.hu>
>>> To: "Steven Hartland" <killing at multiplay.co.uk>
>>> Cc: <freebsd-fs at freebsd.org>
>>> Sent: Friday, December 06, 2013 8:50 AM
>>> Subject: Re: zfs deadlock
>>>
>>>
>>>> What is strange also, when a zfs send finishes, the paralell running
>>>> find command issues errors:
>>>>
>>>> find: ./e/Chuje: No such file or directory
>>>> find: ./e/singe: No such file or directory
>>>> find: ./e/joree: No such file or directory
>>>> find: ./e/fore: No such file or directory
>>>> find: fts_read: No such file or directory
>>>> Fri Dec 6 09:46:04 CET 2013 2
>>>>
>>>> Seems if the filesystem got unmounted meanwhile. But the script is
>>>> changed its working directory to the snapshot dir.
>>>>
>>>> Regards,
>>>>
>>>> 2013-12-06 09:03 időpontban krichy at cflinux.hu ezt írta:
>>>>> Dear Steven,
>>>>>
>>>>> While I was playig with zfs, trying to reproduce the previous bug,
>>>>> accidentaly hit another one, which caused a trace I attached.
>>>>>
>>>>> The snapshot contains directories in 2 depth, which contain files.
>>>>> It
>>>>> was to simulate a vmail setup, with domain/user hierarchy.
>>>>>
>>>>> I hope it is useful for someone.
>>>>>
>>>>> I used the attached two scripts to reproduce the ZFS bug.
>>>>>
>>>>> It definetly crashes the system, in the last 10 minutes it is the
>>>>> 3rd
>>>>> time.
>>>>>
>>>>> Regards,
>>>>> 2013-12-05 20:26 időpontban krichy at cflinux.hu ezt írta:
>>>>>> Dear Steven,
>>>>>>
>>>>>> Thanks for your reply. Do you know how to reproduce the bug?
>>>>>> Because
>>>>>> simply sending a snapshot which is mounted does not automatically
>>>>>> trigger the deadlock. Some special cases needed, or what?
>>>>>> How to prove that the patch fixes this?
>>>>>>
>>>>>> Regards,
>>>>>> 2013-12-05 19:39 időpontban Steven Hartland ezt írta:
>>>>>>> Known issue you want:
>>>>>>> http://svnweb.freebsd.org/changeset/base/258595
>>>>>>>
>>>>>>> Regards
>>>>>>> Steve
>>>>>>>
>>>>>>> ----- Original Message ----- From: "Richard Kojedzinszky"
>>>>>>> <krichy at cflinux.hu>
>>>>>>> To: <freebsd-fs at freebsd.org>
>>>>>>> Sent: Thursday, December 05, 2013 2:56 PM
>>>>>>> Subject: zfs deadlock
>>>>>>>
>>>>>>>
>>>>>>>> Dear fs devs,
>>>>>>>>
>>>>>>>> We have a freenas server, which is basicaly a freebsd. I was
>>>>>>>> trying to look at snapshots using ls .zfs/snapshot/.
>>>>>>>>
>>>>>>>> When I issued it, the system entered a deadlock. An NFSD was
>>>>>>>> running, a zfs send was running when I issued the command.
>>>>>>>>
>>>>>>>> I attached to command outputs while the system was in a deadlock
>>>>>>>> state. I tried to issue
>>>>>>>> # reboot -q
>>>>>>>> But that did not restart the system. After a while (5-10
>>>>>>>> minutes)
>>>>>>>> the system rebooted, I dont know if the deadman caused that.
>>>>>>>>
>>>>>>>> Now the system is up and running.
>>>>>>>>
>>>>>>>> It is basically a freebsd 9.2 kernel.
>>>>>>>>
>>>>>>>> Do someone has a clue?
>>>>>>>>
>>>>>>>> Kojedzinszky Richard
>>>>>>>
>>>>>>>
>>>>>>> --------------------------------------------------------------------------------
>>>>>>>
>>>>>>>
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