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| author | Srinivas Eeda <srinivas.eeda@oracle.com> | 2014-12-11 00:41:48 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-11 02:41:03 +0100 |
| commit | cb79662bc2f83f7b3b60970ad88df43085f96514 (patch) | |
| tree | f4a154486a41682ed7a1288d73ced7e8d2814a6d /sound | |
| parent | ocfs2: report error from o2hb_do_disk_heartbeat() to user (diff) | |
| download | linux-cb79662bc2f83f7b3b60970ad88df43085f96514.tar.xz linux-cb79662bc2f83f7b3b60970ad88df43085f96514.zip | |
ocfs2: o2dlm: fix a race between purge and master query
Node A sends master query request to node B which is the master. At this
time lockres happens to be on purgelist. dlm_master_request_handler gets
the dlm spinlock, finds the resource and releases the dlm spin lock.
Right at this dlm_thread on this node could purge the lockres.
dlm_master_request_handler can then acquire lockres spinlock and reply to
Node A that node B is the master even though lockres on node B is purged.
The above scenario will now make node A falsely think node B is the master
which is inconsistent. Further if another node C tries to master the same
resource, every node will respond they are not the master. Node C then
masters the resource and sends assert master to all nodes. This will now
make node A crash with the following message.
dlm_assert_master_handler:1831 ERROR: DIE! Mastery assert from 9, but current
owner is 10!
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com>
Tested-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'sound')
0 files changed, 0 insertions, 0 deletions