Description of problem:
dlm sometimes randomly crashes while running lvm tests in cluster.
Reproducer not known since there is no pattern preceding this issue.

Version-Release number of selected component (if applicable):
dlm-lib-4.0.6-1.el7.x86_64
dlm-4.0.6-1.el7.x86_64
kernel-3.10.0-514.el7.x86_64

How reproducible:
difficult to reproduce

Steps to Reproduce:
N/A

Console log:

[  286.852890] BUG: scheduling while atomic: kworker/u2:1/36/0x10000200 
[  286.853465] Modules linked in: dlm sd_mod crc_t10dif crct10dif_generic crct10dif_common sg iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi iptable_filter sctp dm_multipath ppdev pcspkr i2c_piix4 i2c_core i6300esb virtio_balloon parport_pc parport nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c ata_generic pata_acpi virtio_net virtio_blk ata_piix libata serio_raw virtio_pci virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod 
[  286.857379] CPU: 0 PID: 36 Comm: kworker/u2:1 Not tainted 3.10.0-514.el7.x86_64 #1 
[  286.857983] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 
[  286.858442] Workqueue: dlm_send process_send_sockets [dlm] 
[  286.858961]  0000000000000000 000000002b9953ad ffff88003a1c3b90 ffffffff81685eac 
[  286.859598]  ffff88003a1c3ba0 ffffffff8167fb4a ffff88003a1c3c00 ffffffff8168b45e 
[  286.860210]  ffff88003a1c8fb0 ffff88003a1c3fd8 ffff88003a1c3fd8 ffff88003a1c3fd8 
[  286.860852] Call Trace: 
[  286.861055]  [<ffffffff81685eac>] dump_stack+0x19/0x1b 
[  286.861409]  [<ffffffff8167fb4a>] __schedule_bug+0x4d/0x5b 
[  286.861833]  [<ffffffff8168b45e>] __schedule+0x89e/0x990 
[  286.862284]  [<ffffffff810c1a66>] __cond_resched+0x26/0x30 
[  286.862732]  [<ffffffff8168b82a>] _cond_resched+0x3a/0x50 
[  286.863165]  [<ffffffff81557828>] lock_sock_nested+0x18/0x50 
[  286.863598]  [<ffffffffa03ca467>] add_sock+0x47/0xe0 [dlm] 
[  286.863996]  [<ffffffffa03cc051>] tcp_connect_to_sock+0x121/0x340 [dlm] 
[  286.864440]  [<ffffffff810ce35c>] ? dequeue_entity+0x11c/0x5d0 
[  286.864871]  [<ffffffff810cec2e>] ? dequeue_task_fair+0x41e/0x660 
[  286.865295]  [<ffffffff810cbcdc>] ? set_next_entity+0x3c/0xe0 
[  286.865695]  [<ffffffffa03cc481>] process_send_sockets+0x191/0x280 [dlm] 
[  286.866312]  [<ffffffff810a7f3b>] process_one_work+0x17b/0x470 
[  286.866783]  [<ffffffff810a8d76>] worker_thread+0x126/0x410 
[  286.867204]  [<ffffffff810a8c50>] ? rescuer_thread+0x460/0x460 
[  286.867672]  [<ffffffff810b052f>] kthread+0xcf/0xe0 
[  286.868043]  [<ffffffff810b0460>] ? kthread_create_on_node+0x140/0x140 
[  286.868566]  [<ffffffff81696418>] ret_from_fork+0x58/0x90 
[  286.868977]  [<ffffffff810b0460>] ? kthread_create_on_node+0x140/0x140