EX-8236 pcc: abort data copy via ll_fid_path_copy

EX-8236 pcc: abort data copy via ll_fid_path_copy

For data copying via ll_fid_path_copy in direct I/O mode in user
space, the client calls llapi_pcc_state_fd() to obtain the file
PCC state. If it is marked with PCC_STATE_FL_ATTACH_ABORTING, the
data copy process ll_fid_path_copy exits immediately.
To reduce the overhead of these check, we do not check for each
data copy iter, instead, we do a check for certain times of I/Os
(32 times by default). For I/O size of 32MiB, it will be checking
1 times per second at 1GiB/s. There should be some time-lag
before the copy tool quits finally.

Change-Id: I20631e5481a7e97d7a1ed0729bcd269ef6248a2c
Signed-off-by: Qian Yingjin <qian@ddn.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/53073
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>