linux_dsm_epyc7002/fs/ocfs2/dlm
Srinivas Eeda cb79662bc2 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>
2014-12-10 17:41:03 -08:00
..
dlmapi.h ocfs2/trivial: Remove trailing whitespaces 2010-01-25 19:20:51 -08:00
dlmast.c ocfs2: use list_for_each_entry() instead of list_for_each() 2013-09-11 15:56:36 -07:00
dlmcommon.h ocfs2/dlm: do not purge lockres that is queued for assert master 2014-06-23 16:47:45 -07:00
dlmconvert.c ocfs2: use list_for_each_entry() instead of list_for_each() 2013-09-11 15:56:36 -07:00
dlmconvert.h [PATCH] OCFS2: The Second Oracle Cluster Filesystem 2006-01-03 11:45:47 -08:00
dlmdebug.c fs/ocfs2/dlm/dlmdebug.c: use seq_open_private() not seq_open() 2014-10-09 22:25:47 -04:00
dlmdebug.h ocfs2/dlm: Cleanup dlmdebug.c 2010-12-22 18:34:44 -08:00
dlmdomain.c ocfs2: fix deadlock between o2hb thread and o2net_wq 2014-10-09 22:25:47 -04:00
dlmdomain.h [PATCH] OCFS2: The Second Oracle Cluster Filesystem 2006-01-03 11:45:47 -08:00
dlmlock.c ocfs2: remove NULL assignments on static 2014-06-04 16:53:53 -07:00
dlmmaster.c ocfs2: o2dlm: fix a race between purge and master query 2014-12-10 17:41:03 -08:00
dlmrecovery.c ocfs2/dlm: let sender retry if dlm_dispatch_assert_master failed with -ENOMEM 2014-12-10 17:41:03 -08:00
dlmthread.c ocfs2/dlm: do not purge lockres that is queued for assert master 2014-06-23 16:47:45 -07:00
dlmunlock.c ocfs2: fix deadlock when two nodes are converting same lock from PR to EX and idletimeout closes conn 2014-06-23 16:47:45 -07:00
Makefile ocfs2: remove versioning information 2014-01-21 16:19:41 -08:00