The following case may lead to o2net_wq and o2hb thread deadlock on
o2hb_callback_sem.
Currently there are 2 nodes say N1, N2 in the cluster. And N2 down, at
the same time, N3 tries to join the cluster. So N1 will handle node
down (N2) and join (N3) simultaneously.
o2hb o2net_wq
->o2hb_do_disk_heartbeat
->o2hb_check_slot
->o2hb_run_event_list
->o2hb_fire_callbacks
->down_write(&o2hb_callback_sem)
->o2net_hb_node_down_cb
->flush_workqueue(o2net_wq)
->o2net_process_message
->dlm_query_join_handler
->o2hb_check_node_heartbeating
->o2hb_fill_node_map
->down_read(&o2hb_callback_sem)
No need to take o2hb_callback_sem in dlm_query_join_handler,
o2hb_live_lock is enough to protect live node map.
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: xMark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: jiangyiwen <jiangyiwen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Export function in o2hb to get a list of heartbeat regions. It also adds an
upper limit to the length of the heartbeat region name.
o2hb_global_heartbeat_active() currently disables global heartbeat. It will
be enabled in a later patch after all the code is added.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
This patch creates a debugfs file, o2hb/livesnodes, which exposes the
aggregate list of heartbeating node across all heartbeat regions.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Lots of people are having trouble with the default timeouts, which are too
low. These new values are derived from an informal survey taken on
ocfs2-users, as well as data from bug reports. This should reduce the amount
of cluster disconnects and subsequent fencing seen during normal workloads.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
ocfs2 mounts require a heartbeat region. Use the new configfs_depend_item()
facility to actually depend on them so they can't go away from under us.
First, teach cluster/nodemanager.c to depend an item on the o2cb subsystem.
Then teach o2hb_register_callbacks to take a UUID and depend on the
appropriate region. Finally, teach all users of o2hb to pass a UUID or
NULL if they don't require a pin.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
If ocfs2_register_hb_callbacks() succeeds on its first callback but fails
its second, it doesn't release the first on the way out. Fix that.
While we're at it, o2hb_unregister_callback() never returns anything but
0, so let's make it void.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Disk based heartbeat. Configured and started from userspace, the
kernel component handles I/O submission and event generation via
callback mechanism.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
