LU-16958 llite: migrate deadlock on not responding lock cancel

LU-16958 llite: migrate deadlock on not responding lock cancel

lfs migrate race makes MDS hang with following backtrace

[ 3683.248584] [<0>] ldlm_completion_ast+0x78d/0x8e0 [ptlrpc]
[ 3683.250122] [<0>] ldlm_cli_enqueue_local+0x2fd/0x840 [ptlrpc]
[ 3683.251363] [<0>] mdt_object_local_lock+0x50e/0xb10 [mdt]
[ 3683.252615] [<0>] mdt_object_lock_internal+0x187/0x430 [mdt]
[ 3683.253793] [<0>] mdt_object_lock_try+0x22/0xa0 [mdt]
[ 3683.254857] [<0>] mdt_getattr_name_lock+0x1317/0x1dc0 [mdt]
[ 3683.256016] [<0>] mdt_intent_getattr+0x264/0x440 [mdt]
[ 3683.257105] [<0>] mdt_intent_opc+0x452/0xa80 [mdt]
[ 3683.258126] [<0>] mdt_intent_policy+0x1fd/0x390 [mdt]
[ 3683.259191] [<0>] ldlm_lock_enqueue+0x469/0xa90 [ptlrpc]
[ 3683.260350] [<0>] ldlm_handle_enqueue0+0x61a/0x16c0 [ptlrpc]
[ 3683.261596] [<0>] tgt_enqueue+0xa4/0x200 [ptlrpc]
[ 3683.262662] [<0>] tgt_request_handle+0xc9c/0x1a40 [ptlrpc]
[ 3683.263860] [<0>] ptlrpc_server_handle_request+0x323/0xbd0 [ptlrpc]
[ 3683.265220] [<0>] ptlrpc_main+0xbf3/0x1540 [ptlrpc]
[ 3683.266303] [<0>] kthread+0x134/0x150
[ 3683.267111] [<0>] ret_from_fork+0x35/0x40

The deadlock happens as follows:
T1:
vvp_io_init()
  ->ll_layout_refresh() <= take lli_layout_mutex
  ->ll_layout_intent()
  ->ll_take_md_lock()  <= take the CR layout lock ref
  ->ll_layout_conf()
    ->vvp_prune()
    ->vvp_inode_ops() <= release lli_layout_mtex
    ->vvp_inode_ops() <= try to acquire lli_layout_mutex
    -> racer wait here for T2
T2:
->ll_file_write_iter()
  ->vvp_io_init()
    ->ll_layout_refresh() <= take lli_layout_mutex
    ->ll_layout_intent() <= Request layout from MDT
    -> racer wait from server...

And server want to cancel the CR layout lock T1 hold, and it won't
happen. Also T1 could has take extent ldlm lock while waiting
lli_layout_mutex hold by T2, and ofd_destroy_hdl does not get the
lock cancellation response from T1.

lli_layout_mutex is only needed for enqueuing layout lock from server,
so that ll_layout_conf() does not involve with lli_layout_mutex.

Fixes: 8f2c1592c3 ("LU-16958 llite: migrate vs regular ops deadlock")
Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: Ib94de2c63544c3a962199aa0537418255980ae8c
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/52388
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Qian Yingjin <qian@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>