blktrace: break mlock in case of is_done.
In 38-rc2, there is a bug in mlock which will return
error in mlock of blktrace(I have sent the corresponding
patch to the lkml). So when we try to break the blktrace
by "ctrl+c", mlock will loop forever and in the end, I
have to use "kill -9" to kill it and then run "blktrace -k"
to stop the tracer. I don't think it is good.
How to reproduce it is simple:
Use a 38-rc kernel, and run
blktrace /dev/sdx
then use "ctrl+c", it doesn't exit.
So this patch adds the check for tp->is_done. In
case of is_done is set, break mlock so that we don't
deadloop in the mlock. In case of the real mlock error,
I will let it to retry 10 times and it should succeed
after 10 tries in case of tp->is_done. If tp isn't set
or tp->is_done isn't set, it works like the original
design.
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
1 file changed
