Bug 871968
Summary: | RPC tasks can deadlock during rpc_shutdown | ||
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Product: | Red Hat Enterprise Linux 6 | Reporter: | Andy Adamson <andros> |
Component: | kernel | Assignee: | Steve Dickson <steved> |
Status: | CLOSED ERRATA | QA Contact: | Eryu Guan <eguan> |
Severity: | high | Docs Contact: | |
Priority: | unspecified | ||
Version: | 6.4 | CC: | dros, dwysocha, eguan, kzhang, steved, tlavigne |
Target Milestone: | rc | Keywords: | Regression |
Target Release: | --- | ||
Hardware: | Unspecified | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | kernel-2.6.32-350.el6 | Doc Type: | Bug Fix |
Doc Text: | Story Points: | --- | |
Clone Of: | Environment: | ||
Last Closed: | 2013-02-21 06:54:51 UTC | Type: | Bug |
Regression: | --- | Mount Type: | --- |
Documentation: | --- | CRM: | |
Verified Versions: | Category: | --- | |
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
Cloudforms Team: | --- | Target Upstream Version: | |
Embargoed: |
Description
Andy Adamson
2012-10-31 21:16:28 UTC
The first patch has a different commit hash: commit 5ca0c0ed6082af0a9089403991d420bae58a555d Author: Weston Andros Adamson <dros> Date: Tue Oct 30 17:01:40 2012 -0400 SUNRPC: add WARN_ON_ONCE for potential deadlock rpc_shutdown_client should never be called from a workqueue context. If it is, it could deadlock looping forever trying to kill tasks that are assigned to the same kworker thread (and will never run rpc_exit_task). Signed-off-by: Weston Andros Adamson <dros> Signed-off-by: Trond Myklebust <Trond.Myklebust> I would also like to point out that this bug is affecting RHEL 6.4 beta testing. You don't need the "--admin-script=./nfsometerlib/scripts/server_ntap.sh --admin-server=<server>" options to nfsometer if the server has read and write delegations enabled. The first run of a dd_* test using v4 will hit this deadlock. You really don't need nfsometer either: 1) mount -o vers=4 server:/export /mnt 2) dd if=/dev/zero of=/mnt/ddfile bs=1024 count=102400 && umount /mnt 3) check /proc/fs/nfsfs/servers - the entry for "server" will never go away. Also one of the kworker threads will be stuck in rpc_shutdown_client. Note there are other ways to hit this deadlock - it's just that the delegreturn path is easier to reproduce. This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux release for currently deployed products. This request is not yet committed for inclusion in a release. Patch(es) Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHSA-2013-0496.html |