Severe contention on kernfs_rwsem that often happens on RHCOS shipped with RHOCP4.9-4.11 causes a system hang

Issue

• Severe contention on kernfs_rwsem that often happens on RHCOS shipped with RHOCP4.9-4.11 causes a system hang

 #0 [ffffbeb85a387b28] __schedule at ffffffff977d5581
 #1 [ffffbeb85a387b80] schedule at ffffffff977d5b45
 #2 [ffffbeb85a387b90] schedule_preempt_disabled at ffffffff977d5e6a
 #3 [ffffbeb85a387b98] rwsem_down_read_slowpath at ffffffff977d848e
 #4 [ffffbeb85a387c38] down_read at ffffffff977d86a5
 #5 [ffffbeb85a387c48] kernfs_iop_permission at ffffffff971e9809
 #6 [ffffbeb85a387c70] inode_permission at ffffffff9715fdfa
 #7 [ffffbeb85a387c98] link_path_walk at ffffffff971604eb
 #8 [ffffbeb85a387cf8] path_lookupat at ffffffff97160767
 #9 [ffffbeb85a387d58] filename_lookup at ffffffff97164c40
#10 [ffffbeb85a387e68] user_statfs at ffffffff9718fc43
#11 [ffffbeb85a387ea8] __do_sys_statfs at ffffffff9718fcc0
#12 [ffffbeb85a387f38] do_syscall_64 at ffffffff96e043ab
#13 [ffffbeb85a387f50] entry_SYSCALL_64_after_hwframe at ffffffff978000a9
    RIP: 00007f4f963a117b  RSP: 00007ffec2fc3268  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 00007f4f96d63f53  RCX: 00007f4f963a117b
    RDX: 00007f4f964eb6f4  RSI: 00007ffec2fc32e0  RDI: 00007f4f96d63f53
    RBP: 00007ffec2fc32e0   R8: 00007f4f975be9c0   R9: 000000000000002f
    R10: fffffffffffffe98  R11: 0000000000000246  R12: 00007ffec2fc3468
    R13: 00007ffec2fc3490  R14: 00007f4f96f6a690  R15: 0000000000000000
    ORIG_RAX: 0000000000000089  CS: 0033  SS: 002b

 #0 [ffffbeb85a457aa8] __schedule at ffffffff977d5581
 #1 [ffffbeb85a457b00] schedule at ffffffff977d5b45
 #2 [ffffbeb85a457b10] schedule_preempt_disabled at ffffffff977d5e6a
 #3 [ffffbeb85a457b18] rwsem_down_read_slowpath at ffffffff977d848e
 #4 [ffffbeb85a457bb0] down_read at ffffffff977d86a5
 #5 [ffffbeb85a457bc0] kernfs_dop_revalidate at ffffffff971eacb5
 #6 [ffffbeb85a457be0] lookup_fast at ffffffff9715ee33
 #7 [ffffbeb85a457c38] walk_component at ffffffff9715f788
 #8 [ffffbeb85a457c98] link_path_walk at ffffffff971603ab
 #9 [ffffbeb85a457cf8] path_lookupat at ffffffff97160767
#10 [ffffbeb85a457d58] filename_lookup at ffffffff97164c40
#11 [ffffbeb85a457e68] user_statfs at ffffffff9718fc43
#12 [ffffbeb85a457ea8] __do_sys_statfs at ffffffff9718fcc0
#13 [ffffbeb85a457f38] do_syscall_64 at ffffffff96e043ab
#14 [ffffbeb85a457f50] entry_SYSCALL_64_after_hwframe at ffffffff978000a9
    RIP: 000055e53bbda21b  RSP: 000000c00014d898  RFLAGS: 00000216
    RAX: ffffffffffffffda  RBX: 000000c000030500  RCX: 000055e53bbda21b
    RDX: 0000000000000000  RSI: 000000c00014d948  RDI: 000000c00013c030
    RBP: 000000c00014d8f8   R8: 00007f55360b7501   R9: 0000000000000001
    R10: 00007f5535f37008  R11: 0000000000000216  R12: 0000000000000000
    R13: 0000000000000000  R14: 000000c0000021a0  R15: ffffffffffffffff
    ORIG_RAX: 0000000000000089  CS: 0033  SS: 002b