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

From: Pavel Begunkov
Date: Sun Jun 07 2020 - 11:34:08 EST


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.

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(-)

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2.24.0