patched upstream in 4.4.55, please upgrade / backport :
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.4.55
commit cd8ad4d9eb6d9ee04e77b42c6a7a15eabada85ac Author: Mikulas Patocka <email address hidden> Date: Wed Feb 15 11:26:10 2017 -0500
dm: flush queued bios when process blocks to avoid deadlock
commit d67a5f4b5947aba4bfe9a80a2b86079c215ca755 upstream.
patched upstream in 4.4.55, please upgrade / backport :
https:/ /cdn.kernel. org/pub/ linux/kernel/ v4.x/ChangeLog- 4.4.55
commit cd8ad4d9eb6d9ee 04e77b42c6a7a15 eabada85ac
Author: Mikulas Patocka <email address hidden>
Date: Wed Feb 15 11:26:10 2017 -0500
dm: flush queued bios when process blocks to avoid deadlock
commit d67a5f4b5947aba 4bfe9a80a2b8607 9c215ca755 upstream.