xfs_inode i_lock deadlock causes system hang

Issue

• A xfs_inode i_lock deadlock causes system hang:

crash> bt ffff8eb99a318000
PID: 56457  TASK: ffff8eb99a318000  CPU: 9   COMMAND: "npm"
 #0 [ffff8ebade317ae8] __schedule at ffffffff8417ebe0
 #1 [ffff8ebade317b70] schedule at ffffffff8417f1c9
 #2 [ffff8ebade317b80] rwsem_down_read_failed at ffffffff84180bb5
 #3 [ffff8ebade317c08] call_rwsem_down_read_failed at ffffffff83d90b88
 #4 [ffff8ebade317c58] down_read at ffffffff8417e350
 #5 [ffff8ebade317c70] xfs_ilock at ffffffffc0640d69 [xfs]
 #6 [ffff8ebade317ca0] xfs_ilock_attr_map_shared at ffffffffc0640e24 [xfs]
 #7 [ffff8ebade317cb8] xfs_attr_get at ffffffffc05f4588 [xfs]
 #8 [ffff8ebade317d88] xfs_xattr_get at ffffffffc064dfcd [xfs]
 #9 [ffff8ebade317da8] generic_getxattr at ffffffff83c70b52
#10 [ffff8ebade317dd8] cap_inode_need_killpriv at ffffffff83cffb5f
#11 [ffff8ebade317de8] security_inode_need_killpriv at ffffffff83d0234c
#12 [ffff8ebade317df8] notify_change at ffffffff83c67a41
#13 [ffff8ebade317e40] chown_common at ffffffff83c45b1c
#14 [ffff8ebade317ee8] sys_fchownat at ffffffff83c470af
#15 [ffff8ebade317f40] sys_chown at ffffffff83c4711d
#16 [ffff8ebade317f50] tracesys at ffffffff8418c172 (via system_call)
    RIP: 00007f43aa56afa7  RSP: 00007f43a1ffadb8  RFLAGS: 00000283
    RAX: ffffffffffffffda  RBX: 00007f43a1ffb630  RCX: ffffffffffffffff
    RDX: 000000003c17e940  RSI: 000000003c17e940  RDI: 0000000004767dd0
    RBP: 00007f43a1ffaeb0   R8: 0000000000000000   R9: 000000000002c8b4
    R10: 0000000000000000  R11: 0000000000000283  R12: 000000000000001a