REVIEW: http://review.gluster.org/16024 (cluster/afr: Remove backward compatibility for locks with v1) posted (#1) for review on master by Pranith Kumar Karampuri (pkarampu)
COMMIT: http://review.gluster.org/16024 committed in master by Pranith Kumar Karampuri (pkarampu) ------ commit c4b39198df40535f589c9304fd07b06d948df2f5 Author: Pranith Kumar K <pkarampu> Date: Mon Dec 5 13:20:51 2016 +0530 cluster/afr: Remove backward compatibility for locks with v1 When we have cascading locks with same lk-owner there is a possibility for a deadlock to happen. One example is as follows: self-heal takes a lock in data-domain for big name with 256 chars of "aaaa...a" and starts heal in a 3-way replication when brick-0 is offline and healing from brick-1 to brick-2 is in progress. So this lock is active on brick-1 and brick-2. Now brick-0 comes online and an operation wants to take full lock and the lock is granted at brick-0 and it is waiting for lock on brick-1. As part of entry healing it takes full locks on all the available bricks and then proceeds with healing the entry. Now this lock will start waiting on brick-0 because some other operation already has a granted lock on it. This leads to a deadlock. Operation is waiting for unlock on "aaaa..." by heal where as heal is waiting for the operation to unlock on brick-0. Initially I thought this is happening because healing is trying to take a lock on all the available bricks instead of just the bricks that are participating in heal. But later realized that same kind of deadlock can happen if a brick goes down after the heal starts but comes back before it completes. So the essential problem is the cascading locks with same lk-owner which were added for backward compatibility with afr-v1 which can be safely removed now that versions with afr-v1 are already EOL. This patch removes the compatibility with v1 which requires cascading locks with same lk-owner. In the next version we can make locking-scheme option a dummy and switch completely to v2. BUG: 1401404 Change-Id: Ic9afab8260f5ff4dff5329eb0429811bcb879079 Signed-off-by: Pranith Kumar K <pkarampu> Reviewed-on: http://review.gluster.org/16024 Smoke: Gluster Build System <jenkins.org> Reviewed-by: Ravishankar N <ravishankar> NetBSD-regression: NetBSD Build System <jenkins.org> CentOS-regression: Gluster Build System <jenkins.org>
This bug is getting closed because a release has been made available that should address the reported issue. In case the problem is still not fixed with glusterfs-3.10.0, please open a new bug report. glusterfs-3.10.0 has been announced on the Gluster mailinglists [1], packages for several distributions should become available in the near future. Keep an eye on the Gluster Users mailinglist [2] and the update infrastructure for your distribution. [1] http://lists.gluster.org/pipermail/gluster-users/2017-February/030119.html [2] https://www.gluster.org/pipermail/gluster-users/