With IORING_SETUP_CQE32 ->cqe_cached doesn't store a real address but
rather an implicit offset into cqes. Store the real cqe pointer and
increment it accordingly if CQE32.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1ee1838cba16bed96381a006950b36ba640d998c.1655455613.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Deduplicate calls to io_get_cqe() from __io_fill_cqe_req().
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4fa077986cc3abab7c59ff4e7c390c783885465f.1655455613.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Deduplicate two trace_io_uring_complete() calls in __io_fill_cqe_req().
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/277ed85dba5189ab7d932164b314013a0f0b0fdc.1655455613.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

__io_fill_cqe_req() is hot and inlined, we want it to be as small as
possible. Add io_req_cqe_overflow() accepting only a request and doing
all overflow accounting, and replace with it two calls to 6 argument
io_cqring_event_overflow().
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/048b9fbcce56814d77a1a540409c98c3d383edcb.1655455613.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

__io_get_cqe() is not as hot as io_get_cqe(), no need to inline it, it
sheds ~500B from the binary.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c1ac829198a881b7af8710926f99a3559b9f24c0.1655455613.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Deduplicate some code and add a helper for filling an aux CQE, locking
and notification.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b7c6557c8f9dc5c4cfb01292116c682a0ff61081.1655455613.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Add comments to explain why it is always under uring lock when
incrementing head in __io_kbuf_recycle. And rectify one comemnt about
kbuf consuming in iowq case.
Signed-off-by: NHao Xu <howeyxu@tencent.com>
Link: https://lore.kernel.org/r/20220617050429.94293-1-hao.xu@linux.devSigned-off-by: NJens Axboe <axboe@kernel.dk>

Currently we do two extra spin lock/unlock pairs to add a poll/apoll
request to the cancellation hash table and remove it from there.

On the submission side we often already hold ->uring_lock and tw
completion is likely to hold it as well. Add a second cancellation hash
table protected by ->uring_lock. In concerns for latency because of a
need to have the mutex locked on the completion side, use the new table
only in following cases:

1) IORING_SETUP_SINGLE_ISSUER: only one task grabs uring_lock, so there
   is little to no contention and so the main tw hander will almost
   always end up grabbing it before calling callbacks.

2) IORING_SETUP_SQPOLL: same as with single issuer, only one task is
   a major user of ->uring_lock.

3) apoll: we normally grab the lock on the completion side anyway to
   execute the request, so it's free.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1bbad9c78c454b7b92f100bbf46730a37df7194f.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b86781d047727c07163443b57551a3fa57c7c5e1.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Instead of passing around a pointer to hash buckets, add a bit of type
safety and wrap it into a structure.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d65bc3faba537ec2aca9eabf334394936d44bd28.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In preparation for having multiple cancellation hash tables, pass a
table pointer into io_poll_find() and other poll cancel functions.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a31c88502463dce09254240fa037352927d7ecc3.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add a new IORING_SETUP_SINGLE_ISSUER flag and the userspace visible part
of it, i.e. put limitations of submitters. Also, don't allow it together
with IOPOLL as we're not going to put it to good use.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4bcc41ee467fdf04c8aab8baf6ce3ba21858c3d4.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Use io_req_task_complete() for poll request completions, so it can
utilise state completions and save lots of unnecessary locking.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ced94cb5a728d8e386c640d052fd3da3f5d6891a.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add a variable for the number of hash buckets in io_ring_ctx_alloc(),
makes it more readable.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/993926ed0d614ba9a76b2a85bebae2babcb13983.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Don't allocate to many hash/cancellation buckets, there might be too
many, clamp it to 8 bits, or 256 * 64B = 16KB. We don't usually have too
many requests, and 256 buckets should be enough, especially since we
do hash search only in the cancellation path.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b9620c8072ba61a2d50eba894b89bd93a94a9abd.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Get rid of an unnecessary extra goto in io_try_cancel() and simplify the
function.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/48cf5417b43a8386c6c364dba1ad9b4c7382d158.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Instead of using implicit knowledge of what is locked or not after
io_poll_find() and co returns, pass back a pointer to the locked
bucket if any. If set the user must to unlock the spinlock.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dae1dc5749aa34367812ecf62f82fd3f053aae44.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add a new io_hash_bucket structure so that each bucket in cancel_hash
has separate spinlock. Use per entry lock for cancel_hash, this removes
some completion lock invocation and remove contension between different
cancel_hash entries.
Signed-off-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/05d1e135b0c8bce9d1441e6346776589e5783e26.1655371007.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

We now don't need to set req->refcount for poll requests since the
reworked poll code ensures no request release race.
Signed-off-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ec6fee45705890bdb968b0c175519242753c0215.1655371007.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

io_put_kbuf() is huge, don't bloat the kernel with inlining.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2e21ccf0be471ffa654032914b9430813cae53f8.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Clean up io_req_task_complete() and deduplicate io_put_kbuf() calls.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ae3148ac7eb5cce3e06895cde306e9e959d6f6ae.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

REQ_F_COMPLETE_INLINE is only needed to delay queueing into the
completion list to io_queue_sqe() as __io_req_complete() is inlined and
we don't want to bloat the kernel.

As now we complete in a more centralised fashion in io_issue_sqe() we
can get rid of the flag and queue to the list directly.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/600ba20a9338b8a39b249b23d3d177803613dde4.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

io_issue_sqe() from the io_uring core knows how to complete requests
based on the returned error code, we can delegate io_read()/io_write()
completion to it. Make kiocb_done() to return the right completion
code and propagate it.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/32ef005b45d23bf6b5e6837740dc0331bb051bd4.1655371007.git.asml.silence@gmail.comReviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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

io_req_task_complete() enqueues requests for state completion itself, no
need for REQ_F_COMPLETE_INLINE, which is only serve the purpose of not
bloating the kernel.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/aca80f71464ad02c06f1311d998a2d6ee0b31573.1655310733.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

All ctx->check_cq events are slow path, don't test every single flag one
by one in the hot path, but add a common guarding if.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dff026585cea7ff3a172a7c83894a3b0111bbf6a.1655310733.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Luckily, nnobody completes multi-apoll requests outside the polling
functions, but don't set IO_URING_F_COMPLETE_DEFER in any case as
there is nobody who is catching REQ_F_COMPLETE_INLINE, and so will leak
requests if used.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a65ed3f5effd9321ee06e6edea294a03be3e15a0.1655310733.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

There can be only 16 registered rings, no need to allocate an array for
them separately but store it in tctx.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/495f0b953c87994dd9e13de2134019054fa5830d.1655310733.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Add a comment on why we keep ->cancel_seq in struct io_wq_work instead
of struct io_kiocb despite it needed only by io_uring but not io-wq.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/988e87eec9dc700b5dae933df3aefef303502f6c.1655310733.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

There is a bunch of inline helpers that will be useful not only to the
core of io_uring, move them to headers.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/22df99c83723e44cba7e945e8519e64e3642c064.1655310733.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Shove all slow path data at the end of ctx and get rid of extra
indention.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/bcaf200298dd469af20787650550efc66d89bef2.1655310733.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Following timeout fields access patterns, move all of them into a
separate cache line inside ctx, so they don't intervene with normal
completion caching, especially since timeout removals and completion
are separated and the later is done via tw.

It also sheds some bytes from io_ring_ctx, 1216B -> 1152B
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4b163793072840de53b3cb66e0c2995e7226ff78.1655310733.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

draining is slow path, move defer_list to the end where slow data lives
inside the context.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e16379391ca72b490afdd24e8944baab849b4a7b.1655310733.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The default (i.e. empty) state of register buffer is dummy_ubuf, so set
it to dummy on init instead of NULL.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c5456aecf03d9627fbd6e65e100e2b5293a6151e.1655310733.git.asml.silence@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

As far as we know, nobody ever adopted the epoll_ctl management via
io_uring. Deprecate it now with a warning, and plan on removing it in
a later kernel version. When we do remove it, we can revert the following
commits as well:

39220e8d ("eventpoll: support non-blocking do_epoll_ctl() calls")
58e41a44 ("eventpoll: abstract out epoll_ctl() handler")
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/io-uring/CAHk-=wiTyisXBgKnVHAGYCNvkmjk=50agS2Uk6nr+n3ssLZg2w@mail.gmail.com/Signed-off-by: NJens Axboe <axboe@kernel.dk>

By default, the POLL_ADD command does edge triggered poll - if we get
a non-zero mask on the initial poll attempt, we complete the request
successfully.

Support level triggered by always waiting for a notification, regardless
of whether or not the initial mask matches the file state.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We already have the declarations in opdef.h, move the rest into its own
file rather than in the main io_uring.c file.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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

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

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