panic error while backup mailboxes with doveadm backup

[Lars]

Hi there is a fix for this bug:

#doveadm -v backup -fu user mdbox: ....

dsync(user): Panic: file dsync-brain-mailbox-tree-sync.c: line 111 (dsync_brain_mailbox_tree_sync_change): assertion failed: (brain->no_backup_overwrite)
dsync(user): Error: Raw backtrace: /usr/lib/dovecot/libdovecot.so.0(+0x5e271) [0x7f60764c1271] -> /usr/lib/dovecot/libdovecot.so.0(default_fatal_handler+0x2a) [0x7f60764c12da] -> /usr/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7f607647ca9e] -> doveadm [user recv_mailbox_tree_deletes](dsync_brain_mailbox_tree_sync_change+0x442) [0x7f60770e0142] -> doveadm [user recv_mailbox_tree_deletes](dsync_brain_recv_mailbox_tree_deletes+0x11b) [0x7f60770dfc4b] -> doveadm [user recv_mailbox_tree_deletes](dsync_brain_run+0x4e3) [0x7f60770dd0b3] -> doveadm [user recv_mailbox_tree_deletes](+0x2d964) [0x7f60770da964] -> doveadm [user recv_mailbox_tree_deletes](+0x15b5b) [0x7f60770c2b5b] -> doveadm [user recv_mailbox_tree_deletes](doveadm_mail_try_run+0x26c) [0x7f60770c38ac] -> doveadm [user recv_mailbox_tree_deletes](main+0x414) [0x7f60770c26d4] -> /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf5) [0x7f60760beec5] -> doveadm [user recv_mailbox_tree_deletes](+0x15922) [0x7f60770c2922]

dovecot-core 2.2.9-1ubuntu2.1 from 14.04 LTS

the fix:
https://<email address hidden>/msg56465.html
http://hg.dovecot.org/dovecot-2.2/rev/fbc8fe46dfce

dovecot-core:
  Installiert: 1:2.2.9-1ubuntu2.1
  Installationskandidat: 1:2.2.9-1ubuntu2.1
  Versionstabelle:
 *** 1:2.2.9-1ubuntu2.1 0
        500 http://de.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
        100 /var/lib/dpkg/status
     1:2.2.9-1ubuntu2 0
        500 http://de.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

this is a show stopper bug because it is our main mail server

Thanks
Lars
---
AlsaDevices:
 total 0
 crw-rw---- 1 root audio 116, 1 Mai 28 09:21 seq
 crw-rw---- 1 root audio 116, 33 Mai 28 09:21 timer
AplayDevices: Error: [Errno 2] No such file or directory
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
CRDA: Error: [Errno 2] No such file or directory
DistroRelease: Ubuntu 14.04
HibernationDevice: RESUME=UUID=4618df75-90fb-4d7a-854e-0e2450e346b0
InstallationDate: Installed on 2014-01-10 (160 days ago)
InstallationMedia: Ubuntu-Server 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140109)
MachineType: Intel Corporation S3420GP
Package: linux (not installed)
PciMultimedia:

ProcEnviron:
 TERM=rxvt
 PATH=(custom, no user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
ProcFB:

ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-27-generic root=UUID=e0a0ee6f-8c04-4b0d-91e7-49b369b09cd4 ro nomdmonddf nomdmonisw
ProcVersionSignature: Ubuntu 3.13.0-27.50-generic 3.13.11
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-27-generic N/A
 linux-backports-modules-3.13.0-27-generic N/A
 linux-firmware 1.127.2
RfKill: Error: [Errno 2] No such file or directory
Tags: trusty
Uname: Linux 3.13.0-27-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

WifiSyslog:

_MarkForUpload: True
dmi.bios.date: 05/11/2012
dmi.bios.vendor: Intel Corp.
dmi.bios.version: S3420GP.86B.01.00.0051.051120121541
dmi.board.asset.tag: ....................
dmi.board.name: S3420GP
dmi.board.vendor: Intel Corporation
dmi.board.version: E51974-406
dmi.chassis.asset.tag: ....................
dmi.chassis.type: 17
dmi.chassis.vendor: IUF-Computer
dmi.chassis.version: ..................
dmi.modalias: dmi:bvnIntelCorp.:bvrS3420GP.86B.01.00.0051.051120121541:bd05/11/2012:svnIntelCorporation:pnS3420GP:pvr....................:rvnIntelCorporation:rnS3420GP:rvrE51974-406:cvnIUF-Computer:ct17:cvr..................:
dmi.product.name: S3420GP
dmi.product.version: ....................
dmi.sys.vendor: Intel Corporation

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1332120

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Lars (lars-taeuber)]

apport information

[Lars (lars-taeuber)]

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[Lars (lars-taeuber)]

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[Lars (lars-taeuber)]

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[Lars (lars-taeuber)]

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[Lars (lars-taeuber)]

apport information

[Lars (lars-taeuber)]

apport information

[Lars (lars-taeuber)]

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[Lars (lars-taeuber)]

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[Lars (lars-taeuber)]

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[Lars (lars-taeuber)]

Is there anyone working on this report?

This isn't only a bug report but also a fix report.
And the fix isn't from someone strange on the net but the original author of dovecot.

So _please_ fix this.
This packet is essential for an imap mail server.

Thanks
Lars

[Lars (lars-taeuber)]

Hi there!

Is there someone reading this report?
The fix is included already.
It is a server critical bug, because it influences the imap backup functionality.

Please give it a chance.

I'm manually repairing the imap backup every time a user deletes an imap folder.

Please. It is the LTS server release!

Thanks
Lars

[Lars (lars-taeuber)]

Is there someone reading this?

* small bug - huge impact on data backup
* easy to fix
* bug fix known since Mon, 03 Feb 2014 11:50:49 -0500
* important package for ubuntu LTS mail server

Thanks
Lars

[Robie Basak (racb)]

Lars,

Sorry, I've only just spotted this. I'll get someone on the server team to take a look. If you want a fix quicker, then the process that needs following is described at https://wiki.ubuntu.com/StableReleaseUpdates#Procedure and https://wiki.ubuntu.com/SponsorshipProcess.

[Robie Basak (racb)]

Further to the patch you proposed there was a subsequent commit "doveadm backup: Fix to handling mailbox deletions." (http://hg.dovecot.org/dovecot-2.2/rev/57a490780b1e) which wipes out the lines changed. And then a further commit "doveadm backup: Another attempt at fixing assert-crashes when deleting mailboxes." (http://hg.dovecot.org/dovecot-2.2/rev/20462a116704) after that.

So it isn't clear to me that the patch you've proposed fixes the issue. There are a bunch of related fixes after those two commits that seem related too (http://hg.dovecot.org/dovecot-2.2/log/tip/src/doveadm/dsync/dsync-mailbox-tree-sync.c)

So I don't think this is trivial to cherry-pick into 14.04 at all. To drive this forward I think we need a comprehensively analysed fix for the issue that we can be confident with. I think we need Timo's input here.

I'm going to remove this from my list of bugs that can be tackled immediately. If someone affected can help us arrive at a patch that comprehensively fixes this problem, then please do. I'll stay subscribed to this bug.

Version 1:2.2.18-2ubuntu2 that is in Wily is subsequent to the patch you proposed, so I'm going to mark this issue fixed in Wily for now, but leaving the task for Trusty open. If this is incorrect, please explain how you have verified this and change the bug status back to New.

[Lars (lars-taeuber)]

Hi Robie,

can you tell me good news? Is there some progress?
I'm sorry I couldn't help further.

Thanks.

[Robie Basak (racb)]

Lars,

As I explained above, I don't think this bug can make any progress without the input of the upstream patch authors. The fixes look very complex to cherry-pick and so risk regression and/or failure to fix the problem for us if we try to backport the fix from Trusty. It needs someone already familiar with the code to advise us or for a skilled developer to spend time becoming familiar with the code. I don't expect the Ubuntu Server Team to make any further progress on this. Volunteers are welcome to prepare a backport, though note that the more complex the backport is, the less likely it is that an Ubuntu developer will be satisfied that it presents a sufficiently low risk of regression of regression to existing 14.04 dovecot users.

Note that this bug is believed fixed in Wily (15.10) , so it is just the Trusty (14.04) backport of the fix that we're talking about here.