JIRA: https://issues.redhat.com/browse/RHEL-64867
commit e5c12945be5016d681ff305ea7306fef5902219d
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Mon Mar 18 22:00:31 2024 +0000
io_uring: refactor io_fill_cqe_req_aux
The restriction on multishot execution context disallowing io-wq is
driven by rules of io_fill_cqe_req_aux(), it should only be called in
the master task context, either from the syscall path or in task_work.
Since task_work now always takes the ctx lock implying
IO_URING_F_COMPLETE_DEFER, we can just assume that the function is
always called with its defer argument set to true.
Kill the argument. Also rename the function for more consistency as
"fill" in CQE related functions was usually meant for raw interfaces
only copying data into the CQ without any locking, waking the user
and other accounting "post" functions take care of.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/93423d106c33116c7d06bf277f651aa68b427328.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-64867
commit 8e5b3b89ecaf6d9295e561c225b35c574a5e0fe7
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Mon Mar 18 22:00:30 2024 +0000
io_uring: remove struct io_tw_state::locked
ctx is always locked for task_work now, so get rid of struct
io_tw_state::locked. Note I'm stopping one step before removing
io_tw_state altogether, which is not empty, because it still serves the
purpose of indicating which function is a tw callback and forcing users
not to invoke them carelessly out of a wrong context. The removal can
always be done later.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/e95e1ea116d0bfa54b656076e6a977bc221392a4.1710799188.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-12076
commit b6b2bb58a75407660f638a68e6e34a07036146d0
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Fri Aug 11 13:53:45 2023 +0100
io_uring: never overflow io_aux_cqe
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 <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/bb20d14d708ea174721e58bb53786b0521e4dd6d.1691757663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-12076
commit a30badf66de8516b5a5bca7a5d339f377ff983ea
Author: Jens Axboe <axboe@kernel.dk>
Date: Fri Jun 23 09:04:35 2023 -0600
io_uring: use cancelation match helper for poll and timeout requests
Get rid of the request vs io_cancel_data checking and just use the
exported helper for this.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-12076
commit faa9c0ee3cab9c68b79183c9e0111ba967d9f402
Author: Jens Axboe <axboe@kernel.dk>
Date: Fri Jun 23 09:34:08 2023 -0600
io_uring/timeout: always set 'ctx' in io_cancel_data
In preparation for using a generic handler to match requests for
cancelation purposes, ensure that ctx is set in io_cancel_data. The
timeout handlers don't check for this as it'll always match, but we'll
need it set going forward.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-12076
commit d86eaed185e9c6052d1ee2ca538f1936ff255887
Author: Jens Axboe <axboe@kernel.dk>
Date: Wed Jun 7 14:41:20 2023 -0600
io_uring: cleanup io_aux_cqe() API
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 <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-12076
commit 5498bf28d8f2bd63a46ad40f4427518615fb793f
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Fri May 19 15:21:16 2023 +0100
io_uring: annotate offset timeout races
It's racy to read ->cached_cq_tail without taking proper measures
(usually grabbing ->completion_lock) as timeout requests with CQE
offsets do, however they have never had a good semantics for from
when they start counting. Annotate racy reads with data_race().
Reported-by: syzbot+cb265db2f3f3468ef436@syzkaller.appspotmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4de3685e185832a92a572df2be2c735d2e21a83d.1684506056.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-12076
commit ea97f6c8558e83cb457c3b5f53351e4fd8519ab1
Author: David Wei <davidhwei@meta.com>
Date: Tue Apr 18 15:58:18 2023 -0700
io_uring: add support for multishot timeouts
A multishot timeout submission will repeatedly generate completions with
the IORING_CQE_F_MORE cflag set. Depending on the value of the `off'
field in the submission, these timeouts can either repeat indefinitely
until cancelled (`off' = 0) or for a fixed number of times (`off' > 0).
Only noseq timeouts (i.e. not dependent on the number of I/O
completions) are supported.
An indefinite timer will be cancelled if the CQ ever overflows.
Signed-off-by: David Wei <davidhwei@meta.com>
Link: https://lore.kernel.org/r/20230418225817.1905027-1-davidhwei@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-12076
Conflicts: We backported the -stable series fix for commit
ef7dfac51d8e ("io_uring/poll: serialize poll linked timer start with
poll removal"), which used a local "locked" variable instead of a
struct io_tw_state. This patch converts the code to the io_tw_state
now that the infrastructure is in place for it. Compare the results
after applying this patch with the output of the following command
run against an upstream kernel:
git show ef7dfac51d8ed961b742218f526bd589f3900a59:io_uring/poll.c
commit a282967c848fb1d92c28334430c472da9c334e54
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Mon Mar 27 16:38:15 2023 +0100
io_uring: encapsulate task_work state
For task works we're passing around a bool pointer for whether the
current ring is locked or not, let's wrap it in a structure, that
will make it more opaque preventing abuse and will also help us
to pass more info in the future if needed.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1ecec9483d58696e248d1bfd52cf62b04442df1d.1679931367.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2068237
commit 6971253f078766543c716db708ba2c787826690d
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Fri Dec 2 17:47:23 2022 +0000
io_uring: revise completion_lock locking
io_kill_timeouts() doesn't post any events but queues everything to
task_work. Locking there is needed for protecting linked requests
traversing, we should grab completion_lock directly instead of using
io_cq_[un]lock helpers. Same goes for __io_req_find_next_prep().
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/88e75d481a65dc295cb59722bb1cf76402d1c06b.1670002973.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2068237
commit ea011ee10231f5fa6cbb415007048ca0bb948baf
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Fri Dec 2 17:47:22 2022 +0000
io_uring: protect cq_timeouts with timeout_lock
Read cq_timeouts in io_flush_timeouts() only after taking the
timeout_lock, as it's protected by it. There are many places where we
also grab ->completion_lock, but for instance io_timeout_fn() doesn't
and still modifies cq_timeouts.
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9c79544dd6cf5c4018cb1bab99cf481a93ea46ef.1670002973.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2068237
commit c0dc995eb2295e1be6b95b60c90c59f87b009bdb
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Thu Sep 8 16:56:57 2022 +0100
io_uring: remove unused return from io_disarm_next
We removed conditional io_commit_cqring_flush() guarding against
spurious eventfd and the io_disarm_next()'s return value is not used
anymore, just void it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9a441c9a32a58bcc586076fa9a7d0dc33f1fb3cb.1662652536.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2068237
commit 37c7bd31b3e9e4b6aee3c5227f789c0b586a33a2
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Sat Jun 25 11:52:58 2022 +0100
io_uring: improve io_fail_links()
io_fail_links() is called with ->completion_lock held and for that
reason we'd want to keep it as small as we can. Instead of doing
__io_req_complete_post() for each linked request under the lock, fail
them in a task_work handler under ->uring_lock.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a2f68708b970a21f4e84ddfa7b3abd67a8fffb27.1656153285.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2068237
commit 88f52eaad2df2cb5ab49b864d79398c9cb9a57f2
Author: Jens Axboe <axboe@kernel.dk>
Date: Sat Jun 18 09:23:54 2022 -0600
io_uring: have cancelation API accept io_uring_task directly
We just use the io_kiocb passed in to find the io_uring_task, and we
already pass in the ctx via cd->ctx anyway.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2068237
commit 253993210bd8aa3b39a392807c03c8ef1cd7dc3d
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Mon Jun 20 01:25:56 2022 +0100
io_uring: introduce locking helpers for CQE posting
spin_lock(&ctx->completion_lock);
/* post CQEs */
io_commit_cqring(ctx);
spin_unlock(&ctx->completion_lock);
io_cqring_ev_posted(ctx);
We have many places repeating this sequence, and the three function
unlock section is not perfect from the maintainance perspective and also
makes it harder to add new locking/sync trick.
Introduce two helpers. io_cq_lock(), which is simple and only grabs
->completion_lock, and io_cq_unlock_post() encapsulating the three call
section.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/fe0c682bf7f7b55d9be55b0d034be9c1949277dc.1655684496.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2068237
commit 305bef98870816ae58357d647521891ec558a92e
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Mon Jun 20 01:25:55 2022 +0100
io_uring: hide eventfd assumptions in eventfd paths
Some io_uring-eventfd users assume that there won't be spurious wakeups.
That assumption has to be honoured by all io_cqring_ev_posted() callers,
which is inconvenient and from time to time leads to problems but should
be maintained to not break the userspace.
Instead of making the callers track whether a CQE was posted or not, hide
it inside io_eventfd_signal(). It saves ->cached_cq_tail it saw last time
and triggers the eventfd only when ->cached_cq_tail changed since then.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0ffc66bae37a2513080b601e4370e147faaa72c5.1655684496.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2068237
commit 48863ffd3e81b6ec98606d3479c50aa77b7a98a9
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Thu Jun 16 13:57:20 2022 +0100
io_uring: clean up tracing events
We have lots of trace events accepting an io_uring request and wanting
to print some of its fields like user_data, opcode, flags and so on.
However, as trace points were unaware of io_uring structures, we had to
pass all the fields as arguments. Teach trace/events/io_uring.h about
struct io_kiocb and stop the misery of passing a horde of arguments to
trace helpers.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/40ff72f92798114e56d400f2b003beb6cde6ef53.1655384063.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2068237
commit 27a9d66fec77cff0e32d2ecd5d0ac7ef878a7bb0
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Thu Jun 16 13:57:18 2022 +0100
io_uring: kill extra io_uring_types.h includes
io_uring/io_uring.h already includes io_uring_types.h, no need to
include it every time. Kill it in a bunch of places, it prepares us for
following patches.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/94d8c943fbe0ef949981c508ddcee7fc1c18850f.1655384063.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2068237
commit 5d7943d99df9326c7b02f773b2d6f09709c30594
Author: Pavel Begunkov <asml.silence@gmail.com>
Date: Thu Jun 16 10:22:11 2022 +0100
io_uring: propagate locking state to poll cancel
Poll cancellation will be soon need to grab ->uring_lock inside, pass
the locking state, i.e. issue_flags, inside the cancellation functions.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b86781d047727c07163443b57551a3fa57c7c5e1.1655371007.git.asml.silence@gmail.com
Reviewed-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2068237
commit 7aaff708a768144ec6459f0a58301be1a6b982fc
Author: Jens Axboe <axboe@kernel.dk>
Date: Wed May 25 20:36:47 2022 -0600
io_uring: move cancelation into its own file
This also helps cleanup the io_uring.h cancel parts, as we can make
things static in the cancel.c file, mostly.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Jeff Moyer