Date: Fri, 06 Dec 2013 16:59:05 +0100 From: krichy@cflinux.hu To: Steven Hartland <killing@multiplay.co.uk> Cc: freebsd-fs@freebsd.org Subject: Re: Re: zfs deadlock Message-ID: <b36ec81192f2d8fa11db5f2433b71456@cflinux.hu> In-Reply-To: <3b3b22b13d8f1cce460da46c0dd71753@cflinux.hu> References: <ce83a25c57a1d62abce7a002e8da2949@cflinux.hu> <DF23B67C7A294429B5D47D7186156BEC@multiplay.co.uk> <3b3b22b13d8f1cce460da46c0dd71753@cflinux.hu>
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So maybe the force flag is too strict. Under linux the snapshots remains mounted after a send. 2013-12-06 16:54 időpontban krichy@cflinux.hu ezt írta: > 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@cflinux.hu> >> To: <smh@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@cflinux.hu >>> Címzett: freebsd-fs@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@cflinux.hu> >>>> To: "Steven Hartland" <killing@multiplay.co.uk> >>>> Cc: <freebsd-fs@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@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@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@cflinux.hu> >>>>>>>> To: <freebsd-fs@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 >>>>>>>> >>>>>>>> >>>>>>>> -------------------------------------------------------------------------------- >>>>>>>> >>>>>>>> >>>>>>>>> _______________________________________________ >>>>>>>>> freebsd-fs@freebsd.org mailing list >>>>>>>>> http://lists.freebsd.org/mailman/listinfo/freebsd-fs >>>>>>>>> To unsubscribe, send any mail to >>>>>>>>> "freebsd-fs-unsubscribe@freebsd.org" >>>>>>>> >>>>>>>> ================================================ >>>>>>>> This e.mail is private and confidential between Multiplay (UK) >>>>>>>> Ltd. >>>>>>>> and the person or entity to whom it is addressed. In the event >>>>>>>> of >>>>>>>> misdirection, the recipient is prohibited from using, copying, >>>>>>>> printing or otherwise disseminating it or any information >>>>>>>> contained >>>>>>>> in >>>>>>>> it. >>>>>>>> >>>>>>>> In the event of misdirection, illegible or incomplete >>>>>>>> transmission >>>>>>>> please telephone +44 845 868 1337 >>>>>>>> or return the E.mail to postmaster@multiplay.co.uk. >>>>> >>>> >>>> >>>> ================================================ >>>> This e.mail is private and confidential between Multiplay (UK) Ltd. >>>> and the person or entity to whom it is addressed. In the event of >>>> misdirection, the recipient is prohibited from using, copying, >>>> printing or otherwise disseminating it or any information contained >>>> in >>>> it. >>>> >>>> In the event of misdirection, illegible or incomplete transmission >>>> please telephone +44 845 868 1337 >>>> or return the E.mail to postmaster@multiplay.co.uk. >> >> >> ================================================ >> This e.mail is private and confidential between Multiplay (UK) Ltd. >> and the person or entity to whom it is addressed. In the event of >> misdirection, the recipient is prohibited from using, copying, >> printing or otherwise disseminating it or any information contained in >> it. >> >> In the event of misdirection, illegible or incomplete transmission >> please telephone +44 845 868 1337 >> or return the E.mail to postmaster@multiplay.co.uk.
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