linux-stable.git/io_uring/poll.c, branch v6.6.26

io_uring: fix poll_remove stalled req completion

2024-03-26T22:20:09+00:00

[ Upstream commit 5e3afe580a9f5ca173a6bd55ffe10948796ef7e5 ]

Taking the ctx lock is not enough to use the deferred request completion
infrastructure, it'll get queued into the list but no one would expect
it there, so it will sit there until next io_submit_flush_completions().
It's hard to care about the cancellation path, so complete it via tw.

Fixes: ef7dfac51d8ed ("io_uring/poll: serialize poll linked timer start with poll removal")
Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/c446740bc16858f8a2a8dcdce899812f21d15f23.1710514702.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

io_uring/poll: add requeue return code from poll multishot handling

2024-02-16T18:10:56+00:00

Commit 704ea888d646cb9d715662944cf389c823252ee0 upstream.

Since our poll handling is edge triggered, multishot handlers retry
internally until they know that no more data is available. In
preparation for limiting these retries, add an internal return code,
IOU_REQUEUE, which can be used to inform the poll backend about the
handler wanting to retry, but that this should happen through a normal
task_work requeue rather than keep hammering on the issue side for this
one request.

No functional changes in this patch, nobody is using this return code
just yet.

Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

io_uring/poll: move poll execution helpers higher up

2024-02-16T18:10:56+00:00

Commit e84b01a880f635e3084a361afba41f95ff500d12 upstream.

In preparation for calling __io_poll_execute() higher up, move the
functions to avoid forward declarations.

No functional changes in this patch.

Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

io_uring: never overflow io_aux_cqe

2023-08-11T16:42:57+00:00

Now all callers of io_aux_cqe() set allow_overflow to false, remove the
parameter and not allow overflowing auxilary multishot cqes.

When CQ is full the function callers and all multishot requests in
general are expected to complete the request. That prevents indefinite
in-background grows of the overflow list and let's the userspace to
handle the backlog at its own pace.

Resubmitting a request should also be faster than accounting a bunch of
overflows, so it should be better for perf when it happens, but a well
behaving userspace should be trying to avoid overflows in any case.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/bb20d14d708ea174721e58bb53786b0521e4dd6d.1691757663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring/cancel: support opcode based lookup and cancelation

2023-07-17T16:05:48+00:00

Add IORING_ASYNC_CANCEL_OP flag for cancelation, which allows the
application to target cancelation based on the opcode of the original
request.

Signed-off-by: Jens Axboe

io_uring: use cancelation match helper for poll and timeout requests

2023-07-17T16:05:48+00:00

Get rid of the request vs io_cancel_data checking and just use the
exported helper for this.

Signed-off-by: Jens Axboe

io_uring/poll: always set 'ctx' in io_cancel_data

2023-07-17T16:05:48+00:00

This isn't strictly necessary for this callsite, as it uses it's
internal lookup for this cancelation purpose. But let's be consistent
with how it's used in general and set ctx as well.

Signed-off-by: Jens Axboe

Merge tag 'for-6.5/io_uring-2023-06-23' of git://git.kernel.dk/linux

2023-06-26T19:30:26+00:00

Pull io_uring updates from Jens Axboe:
 "Nothing major in this release, just a bunch of cleanups and some
  optimizations around networking mostly.

   - clean up file request flags handling (Christoph)

   - clean up request freeing and CQ locking (Pavel)

   - support for using pre-registering the io_uring fd at setup time
     (Josh)

   - Add support for user allocated ring memory, rather than having the
     kernel allocate it. Mostly for packing rings into a huge page (me)

   - avoid an unnecessary double retry on receive (me)

   - maintain ordering for task_work, which also improves performance
     (me)

   - misc cleanups/fixes (Pavel, me)"

* tag 'for-6.5/io_uring-2023-06-23' of git://git.kernel.dk/linux: (39 commits)
  io_uring: merge conditional unlock flush helpers
  io_uring: make io_cq_unlock_post static
  io_uring: inline __io_cq_unlock
  io_uring: fix acquire/release annotations
  io_uring: kill io_cq_unlock()
  io_uring: remove IOU_F_TWQ_FORCE_NORMAL
  io_uring: don't batch task put on reqs free
  io_uring: move io_clean_op()
  io_uring: inline io_dismantle_req()
  io_uring: remove io_free_req_tw
  io_uring: open code io_put_req_find_next
  io_uring: add helpers to decode the fixed file file_ptr
  io_uring: use io_file_from_index in io_msg_grab_file
  io_uring: use io_file_from_index in __io_sync_cancel
  io_uring: return REQ_F_ flags from io_file_get_flags
  io_uring: remove io_req_ffs_set
  io_uring: remove a confusing comment above io_file_get_flags
  io_uring: remove the mode variable in io_file_get_flags
  io_uring: remove __io_file_supports_nowait
  io_uring: wait interruptibly for request completions on exit
  ...

io_uring/poll: serialize poll linked timer start with poll removal

2023-06-18T02:21:52+00:00

We selectively grab the ctx->uring_lock for poll update/removal, but
we really should grab it from the start to fully synchronize with
linked timeouts. Normally this is indeed the case, but if requests
are forced async by the application, we don't fully cover removal
and timer disarm within the uring_lock.

Make this simpler by having consistent locking state for poll removal.

Cc: stable@vger.kernel.org # 6.1+
Reported-by: Querijn Voet 
Signed-off-by: Jens Axboe

io_uring: cleanup io_aux_cqe() API

2023-06-07T20:59:22+00:00

Everybody is passing in the request, so get rid of the io_ring_ctx and
explicit user_data pass-in. Both the ctx and user_data can be deduced
from the request at hand.

Signed-off-by: Jens Axboe