tree 0462f8ea106520c3426001230a5f858d229bf9ec
parent eb85890b29e4d7ae1accdcfba35ed8b16ba9fb97
author Jens Axboe <axboe@kernel.dk> 1614273429 -0700
committer Jens Axboe <axboe@kernel.dk> 1614273429 -0700

io-wq: improve manager/worker handling over exec

exec will cancel any threads, including the ones that io-wq is using. This
isn't a problem, in fact we'd prefer it to be that way since it means we
know that any async work cancels naturally without having to handle it
proactively.

But it does mean that we need to setup a new manager, as the manager and
workers are gone. Handle this at queue time, and cancel work if we fail.
Since the manager can go away without us noticing, ensure that the manager
itself holds a reference to the 'wq' as well. Rename io_wq_destroy() to
io_wq_put() to reflect that.

In the future we can now simplify exec cancelation handling, for now just
leave it the same.

Signed-off-by: Jens Axboe <axboe@kernel.dk>