[LU-13987] Don't re-enqueue glimpse lock on read

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.14.0
• Severity: 3
• Assignee: Andriy Skulysh
• Reporter: Andriy Skulysh

Description

PID: 114738  TASK: ffff9badebb64100  CPU: 18  COMMAND: "cat"
 #0 [ffff9ba732603668] __schedule at ffffffff87b67747
 #1 [ffff9ba7326036f0] schedule at ffffffff87b67c49
 #2 [ffff9ba732603700] obd_get_request_slot at ffffffffc0dbe0a4 [obdclass]
 #3 [ffff9ba7326037b8] ldlm_cli_enqueue at ffffffffc0faedce [ptlrpc]
 #4 [ffff9ba732603878] mdc_enqueue_send at ffffffffc11b38a8 [mdc]
 #5 [ffff9ba732603938] mdc_lock_enqueue at ffffffffc11b3eb2 [mdc]
 #6 [ffff9ba7326039a8] cl_lock_enqueue at ffffffffc0dfee95 [obdclass]
 #7 [ffff9ba7326039e0] lov_lock_enqueue at ffffffffc10ef265 [lov]
 #8 [ffff9ba732603a20] cl_lock_enqueue at ffffffffc0dfee95 [obdclass]
 #9 [ffff9ba732603a58] cl_lock_request at ffffffffc0dff54b [obdclass]
#10 [ffff9ba732603a90] cl_glimpse_lock at ffffffffc122fd41 [lustre]
#11 [ffff9ba732603ad8] vvp_prep_size at ffffffffc123623d [lustre]
#12 [ffff9ba732603b38] vvp_io_read_start at ffffffffc1237862 [lustre]
#13 [ffff9ba732603be0] cl_io_start at ffffffffc0e01458 [obdclass]
#14 [ffff9ba732603c08] cl_io_loop at ffffffffc0e036bc [obdclass]
#15 [ffff9ba732603c38] ll_file_io_generic at ffffffffc11ee067 [lustre]
#16 [ffff9ba732603d50] ll_file_aio_read at ffffffffc11ef67f [lustre]
#17 [ffff9ba732603df0] ll_file_read at ffffffffc11ef820 [lustre]

cl_glimpse_lock() doesn't match a lock with LDLM_FL_BL_AST even if this lock is acquired by the same thread earlier.