Processes stuck on rw_semaphore with no current holder.

Issue

• The kernel hung task watchdog reports processes as blocked:

INFO: task nbemm:3945 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
nbemm         D 0000000000000001     0  3945      1 0x00000000
 ffff8817eb5dfe08 0000000000000086 ffff8817eb5dfe48 ffff8817e5826cc0
 ffff8817e335b800 ffffffff8120d6af ffff8817eb5dfd98 ffff880bde4c83c0
 ffff8817ec255ab8 ffff8817eb5dffd8 000000000000f4e8 ffff8817ec255ab8
Call Trace:
 [<ffffffff8120d6af>] ? security_inode_permission+0x1f/0x30
 [<ffffffff811877da>] ? do_filp_open+0x6da/0xd60
 [<ffffffff814ef4b5>] rwsem_down_failed_common+0x95/0x1d0
 [<ffffffff814ef613>] rwsem_down_write_failed+0x23/0x30
 [<ffffffff81277203>] call_rwsem_down_write_failed+0x13/0x20
 [<ffffffff814eeb12>] ? down_write+0x32/0x40
 [<ffffffff81131f7c>] sys_mmap_pgoff+0x5c/0x2d0
 [<ffffffff81010469>] sys_mmap+0x29/0x30
 [<ffffffff8100b0f2>] system_call_fastpath+0x16/0x1b
Kernel panic - not syncing: hung_task: blocked tasks