From owner-freebsd-fs@FreeBSD.ORG Fri Dec 6 15:55:01 2013 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 4ED697AF for ; Fri, 6 Dec 2013 15:55:01 +0000 (UTC) Received: from pi.nmdps.net (pi.nmdps.net [IPv6:2a01:be00:10:201:0:80:0:1]) by mx1.freebsd.org (Postfix) with ESMTP id B8E0118E5 for ; Fri, 6 Dec 2013 15:55:00 +0000 (UTC) Received: from pi.nmdps.net (localhost [127.0.0.1]) (Authenticated sender: krichy@cflinux.hu) by pi.nmdps.net (Postfix) with ESMTPSA id CD5C51697; Fri, 6 Dec 2013 16:54:59 +0100 (CET) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Fri, 06 Dec 2013 16:54:57 +0100 From: krichy@cflinux.hu To: Steven Hartland Subject: Re: Re: zfs deadlock In-Reply-To: References: Message-ID: <3b3b22b13d8f1cce460da46c0dd71753@cflinux.hu> X-Sender: krichy@cflinux.hu User-Agent: Roundcube Webmail/0.9.5 Cc: freebsd-fs@freebsd.org X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 06 Dec 2013 15:55:01 -0000 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: > To: > 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: >>> To: "Steven Hartland" >>> Cc: >>> 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" >>>>>>> >>>>>>> To: >>>>>>> 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. 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