[PATCH v2 0/4][RESEND] cancel all reqs of an exiting task

[Pavel Begunkov <asml.silence@gmail.com>]

io_uring_flush() {
        ...
        if (fatal_signal_pending(current) || (current->flags & PF_EXITING))
                io_wq_cancel_pid(ctx->io_wq, task_pid_vnr(current));
}

This cancels only the first matched request. The pathset is mainly
about fixing that. [1,2] are preps, [3/4] is the fix.

The [4/4] tries to improve the worst case for io_uring_cancel_files(),
that's when they are a lot of inflights with ->files. Instead of doing
{kill(); wait();} one by one, it cancels all of them at once.

v2: rebase

Pavel Begunkov (4):
  io-wq: reorder cancellation pending -> running
  io-wq: add an option to cancel all matched reqs
  io_uring: cancel all task's requests on exit
  io_uring: batch cancel in io_uring_cancel_files()

 fs/io-wq.c    | 108 ++++++++++++++++++++++++++------------------------
 fs/io-wq.h    |   3 +-
 fs/io_uring.c |  29 ++++++++++++--
 3 files changed, 83 insertions(+), 57 deletions(-)

-- 
2.24.0