Commit Graph

31 Commits

Author SHA1 Message Date
Jens Axboe
f688944cfb io_uring/rw: add separate prep handler for fixed read/write
Rather than sprinkle opcode checks in the generic read/write prep handler,
have a separate prep handler for the vectored readv/writev operation.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-06 07:43:16 -07:00
Jens Axboe
0e984ec88d io_uring/rw: add separate prep handler for readv/writev
Rather than sprinkle opcode checks in the generic read/write prep handler,
have a separate prep handler for the vectored readv/writev operation.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-06 07:41:17 -07:00
Jens Axboe
8f350194d5 io_uring: add support for vectored futex waits
This adds support for IORING_OP_FUTEX_WAITV, which allows registering a
notification for a number of futexes at once. If one of the futexes are
woken, then the request will complete with the index of the futex that got
woken as the result. This is identical to what the normal vectored futex
waitv operation does.

Use like IORING_OP_FUTEX_WAIT, except sqe->addr must now contain a
pointer to a struct futex_waitv array, and sqe->off must now contain the
number of elements in that array. As flags are passed in the futex_vector
array, and likewise for the value and futex address(es), sqe->addr2
and sqe->addr3 are also reserved for IORING_OP_FUTEX_WAITV.

For cancelations, FUTEX_WAITV does not rely on the futex_unqueue()
return value as we're dealing with multiple futexes. Instead, a separate
per io_uring request atomic is used to claim ownership of the request.

Waiting on N futexes could be done with IORING_OP_FUTEX_WAIT as well,
but that punts a lot of the work to the application:

1) Application would need to submit N IORING_OP_FUTEX_WAIT requests,
   rather than just a single IORING_OP_FUTEX_WAITV.

2) When one futex is woken, application would need to cancel the
   remaining N-1 requests that didn't trigger.

While this is of course doable, having a single vectored futex wait
makes for much simpler application code.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-29 02:37:08 -06:00
Jens Axboe
194bb58c60 io_uring: add support for futex wake and wait
Add support for FUTEX_WAKE/WAIT primitives.

IORING_OP_FUTEX_WAKE is mix of FUTEX_WAKE and FUTEX_WAKE_BITSET, as
it does support passing in a bitset.

Similary, IORING_OP_FUTEX_WAIT is a mix of FUTEX_WAIT and
FUTEX_WAIT_BITSET.

For both of them, they are using the futex2 interface.

FUTEX_WAKE is straight forward, as those can always be done directly from
the io_uring submission without needing async handling. For FUTEX_WAIT,
things are a bit more complicated. If the futex isn't ready, then we
rely on a callback via futex_queue->wake() when someone wakes up the
futex. From that calback, we queue up task_work with the original task,
which will post a CQE and wake it, if necessary.

Cancelations are supported, both from the application point-of-view,
but also to be able to cancel pending waits if the ring exits before
all events have occurred. The return value of futex_unqueue() is used
to gate who wins the potential race between cancelation and futex
wakeups. Whomever gets a 'ret == 1' return from that claims ownership
of the io_uring futex request.

This is just the barebones wait/wake support. PI or REQUEUE support is
not added at this point, unclear if we might look into that later.

Likewise, explicit timeouts are not supported either. It is expected
that users that need timeouts would do so via the usual io_uring
mechanism to do that using linked timeouts.

The SQE format is as follows:

`addr`		Address of futex
`fd`		futex2(2) FUTEX2_* flags
`futex_flags`	io_uring specific command flags. None valid now.
`addr2`		Value of futex
`addr3`		Mask to wake/wait

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-29 02:36:57 -06:00
Jens Axboe
f31ecf671d io_uring: add IORING_OP_WAITID support
This adds support for an async version of waitid(2), in a fully async
version. If an event isn't immediately available, wait for a callback
to trigger a retry.

The format of the sqe is as follows:

sqe->len		The 'which', the idtype being queried/waited for.
sqe->fd			The 'pid' (or id) being waited for.
sqe->file_index		The 'options' being set.
sqe->addr2		A pointer to siginfo_t, if any, being filled in.

buf_index, add3, and waitid_flags are reserved/unused for now.
waitid_flags will be used for options for this request type. One
interesting use case may be to add multi-shot support, so that the
request stays armed and posts a notification every time a monitored
process state change occurs.

Note that this does not support rusage, on Arnd's recommendation.

See the waitid(2) man page for details on the arguments.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-21 12:04:45 -06:00
Jens Axboe
fc68fcda04 io_uring/rw: add support for IORING_OP_READ_MULTISHOT
This behaves like IORING_OP_READ, except:

1) It only supports pollable files (eg pipes, sockets, etc). Note that
   for sockets, you probably want to use recv/recvmsg with multishot
   instead.

2) It supports multishot mode, meaning it will repeatedly trigger a
   read and fill a buffer when data is available. This allows similar
   use to recv/recvmsg but on non-sockets, where a single request will
   repeatedly post a CQE whenever data is read from it.

3) Because of #2, it must be used with provided buffers. This is
   uniformly true across any request type that supports multishot and
   transfers data, with the reason being that it's obviously not
   possible to pass in a single buffer for the data, as multiple reads
   may very well trigger before an application has a chance to process
   previous CQEs and the data passed from them.

Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-21 12:02:30 -06:00
Jens Axboe
d2d778fbf9 io_uring/rw: mark readv/writev as vectored in the opcode definition
This is cleaner than gating on the opcode type, particularly as more
read/write type opcodes may be added.

Then we can use that for the data import, and for __io_read() on
whether or not we need to copy state.

Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-21 12:00:46 -06:00
Breno Leitao
fd9b8547bc io_uring: Pass whole sqe to commands
Currently uring CMD operation relies on having large SQEs, but future
operations might want to use normal SQE.

The io_uring_cmd currently only saves the payload (cmd) part of the SQE,
but, for commands that use normal SQE size, it might be necessary to
access the initial SQE fields outside of the payload/cmd block.  So,
saves the whole SQE other than just the pdu.

This changes slightly how the io_uring_cmd works, since the cmd
structures and callbacks are not opaque to io_uring anymore. I.e, the
callbacks can look at the SQE entries, not only, in the cmd structure.

The main advantage is that we don't need to create custom structures for
simple commands.

Creates io_uring_sqe_cmd() that returns the cmd private data as a null
pointer and avoids casting in the callee side.
Also, make most of ublk_drv's sqe->cmd priv structure into const, and use
io_uring_sqe_cmd() to get the private structure, removing the unwanted
cast. (There is one case where the cast is still needed since the
header->{len,addr} is updated in the private structure)

Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20230504121856.904491-3-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-04 08:19:05 -06:00
Richard Guy Briggs
fbe870a72f io_uring,audit: don't log IORING_OP_MADVISE
fadvise and madvise both provide hints for caching or access pattern for
file and memory respectively.  Skip them.

Fixes: 5bd2182d58 ("audit,io_uring,io-wq: add some basic audit support to io_uring")
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Link: https://lore.kernel.org/r/b5dfdcd541115c86dbc774aa9dd502c964849c5f.1675282642.git.rgb@redhat.com
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-10 16:00:30 -07:00
Breno Leitao
f30bd4d038 io_uring: Split io_issue_def struct
This patch removes some "cold" fields from `struct io_issue_def`.

The plan is to keep only highly used fields into `struct io_issue_def`, so,
it may be hot in the cache. The hot fields are basically all the bitfields
and the callback functions for .issue and .prep.

The other less frequently used fields are now located in a secondary and
cold struct, called `io_cold_def`.

This is the size for the structs:

Before: io_issue_def = 56 bytes
After: io_issue_def = 24 bytes; io_cold_def = 40 bytes

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20230112144411.2624698-2-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Breno Leitao
a7dd27828b io_uring: Rename struct io_op_def
The current io_op_def struct is becoming huge and the name is a bit
generic.

The goal of this patch is to rename this struct to `io_issue_def`. This
struct will contain the hot functions associated with the issue code
path.

For now, this patch only renames the structure, and an upcoming patch
will break up the structure in two, moving the non-issue fields to a
secondary struct.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20230112144411.2624698-1-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:17:41 -07:00
Pavel Begunkov
11373026f2 io_uring: get rid of double locking
We don't need to take both uring_locks at once, msg_ring can be split in
two parts, first getting a file from the filetable of the first ring and
then installing it into the second one.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a80ecc2bc99c3b3f2cf20015d618b7c51419a797.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Pavel Begunkov
ef0ec1ad03 io_uring: dont remove file from msg_ring reqs
We should not be messing with req->file outside of core paths. Clearing
it makes msg_ring non reentrant, i.e. luckily io_msg_send_fd() fails the
request on failed io_double_lock_ctx() but clearly was originally
intended to do retries instead.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e5ac9edadb574fe33f6d727cb8f14ce68262a684.1670384893.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-12-07 06:47:13 -07:00
Jens Axboe
11528491c6 io_uring/opdef: remove 'audit_skip' from SENDMSG_ZC
The msg variants of sending aren't audited separately, so we should not
be setting audit_skip for the zerocopy sendmsg variant either.

Fixes: 493108d95f ("io_uring/net: zerocopy sendmsg")
Reported-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-10-12 16:30:56 -06:00
Pavel Begunkov
493108d95f io_uring/net: zerocopy sendmsg
Add a zerocopy version of sendmsg.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/6aabc4bdfc0ec78df6ec9328137e394af9d4e7ef.1663668091.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 13:15:02 -06:00
Pavel Begunkov
c4c0009e0b io_uring/net: combine fail handlers
Merge io_send_zc_fail() into io_sendrecv_fail(), saves a few lines of
code and some headache for following patch.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e0eba1d577413aef5602cd45f588b9230207082d.1663668091.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 13:15:02 -06:00
Pavel Begunkov
b0e9b5517e io_uring/net: rename io_sendzc()
Simple renaming of io_sendzc*() functions in preparatio to adding
a zerocopy sendmsg variant.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/265af46829e6076dd220011b1858dc3151969226.1663668091.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 13:15:02 -06:00
Pavel Begunkov
516e82f0e0 io_uring/net: support non-zerocopy sendto
We have normal sends, but what is missing is sendto-like requests. Add
sendto() capabilities to IORING_OP_SEND by passing in addr just as we do
for IORING_OP_SEND_ZC.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/69fbd8b2cb830e57d1bf9ec351e9bf95c5b77e3f.1663668091.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 13:15:02 -06:00
Pavel Begunkov
5693bcce89 io_uring/net: don't lose partial send_zc on fail
Partial zc send may end up in io_req_complete_failed(), which not only
would return invalid result but also mask out the notification leading
to lifetime issues.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5673285b5e83e6ceca323727b4ddaa584b5cc91e.1663668091.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 13:15:02 -06:00
Pavel Begunkov
7e6b638ed5 io_uring/net: don't lose partial send/recv on fail
Just as with rw, partial send/recv may end up in
io_req_complete_failed() and loose the result, make sure we return the
number of bytes processed.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a4ff95897b5419356fca9ea55db91ac15b2975f9.1663668091.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 13:15:02 -06:00
Pavel Begunkov
47b4c68660 io_uring/rw: don't lose partial IO result on fail
A partially done read/write may end up in io_req_complete_failed() and
loose the result, make sure we return the number of bytes processed.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/05e0879c226bcd53b441bf92868eadd4bf04e2fc.1663668091.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 13:15:02 -06:00
Pavel Begunkov
858c293e5d io_uring/net: use async caches for async prep
send/recv have async_data caches but there are only used from within
issue handlers. Extend their use also to ->prep_async, should be handy
with links and IOSQE_ASYNC.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b9a2264b807582a97ed606c5bfcdc2399384e8a5.1662639236.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 10:30:43 -06:00
Kanchan Joshi
5756a3a7e7 io_uring: add iopoll infrastructure for io_uring_cmd
Put this up in the same way as iopoll is done for regular read/write IO.
Make place for storing a cookie into struct io_uring_cmd on submission.
Perform the completion using the ->uring_cmd_iopoll handler.

Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20220823161443.49436-3-joshi.k@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21 10:30:42 -06:00
Stefan Metzmacher
9bd3f72822 io_uring/opdef: rename SENDZC_NOTIF to SEND_ZC
It's confusing to see the string SENDZC_NOTIF in ftrace output
when using IORING_OP_SEND_ZC.

Fixes: b48c312be0 ("io_uring/net: simplify zerocopy send user API")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: io-uring@vger.kernel.org
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8e5cd8616919c92b6c3c7b6ea419fdffd5b97f3c.1663363798.git.metze@samba.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-18 06:59:13 -06:00
Pavel Begunkov
b48c312be0 io_uring/net: simplify zerocopy send user API
Following user feedback, this patch simplifies zerocopy send API. One of
the main complaints is that the current API is difficult with the
userspace managing notification slots, and then send retries with error
handling make it even worse.

Instead of keeping notification slots change it to the per-request
notifications model, which posts both completion and notification CQEs
for each request when any data has been sent, and only one CQE if it
fails. All notification CQEs will have IORING_CQE_F_NOTIF set and
IORING_CQE_F_MORE in completion CQEs indicates whether to wait a
notification or not.

IOSQE_CQE_SKIP_SUCCESS is disallowed with zerocopy sends for now.

This is less flexible, but greatly simplifies the user API and also the
kernel implementation. We reuse notif helpers in this patch, but in the
future there won't be need for keeping two requests.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/95287640ab98fc9417370afb16e310677c63e6ce.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-01 09:13:33 -06:00
Pavel Begunkov
d9808ceb31 Revert "io_uring: rename IORING_OP_FILES_UPDATE"
This reverts commit 4379d5f15b.

We removed notification flushing, also cleanup uapi preparation changes
to not pollute it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/89edc3905350f91e1b6e26d9dbf42ee44fd451a2.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-01 09:13:33 -06:00
Pavel Begunkov
581711c466 io_uring/net: save address for sendzc async execution
We usually copy all bits that a request needs from the userspace for
async execution, so the userspace can keep them on the stack. However,
send zerocopy violates this pattern for addresses and may reloads it
e.g. from io-wq. Save the address if any in ->async_data as usual.

Reported-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d7512d7aa9abcd36e9afe1a4d292a24cb2d157e5.1661342812.git.asml.silence@gmail.com
[axboe: fold in incremental fix]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-25 07:52:30 -06:00
Pavel Begunkov
4379d5f15b io_uring: rename IORING_OP_FILES_UPDATE
IORING_OP_FILES_UPDATE will be a more generic opcode serving different
resource types, rename it into IORING_OP_RSRC_UPDATE and add subtype
handling.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0a907133907d9af3415a8a7aa1802c6aa97c03c6.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:41:07 -06:00
Pavel Begunkov
06a5464be8 io_uring: wire send zc request type
Add a new io_uring opcode IORING_OP_SENDZC. The main distinction from
IORING_OP_SEND is that the user should specify a notification slot
index in sqe::notification_idx and the buffers are safe to reuse only
when the used notification is flushed and completes.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/a80387c6a68ce9cf99b3b6ef6f71068468761fb7.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:41:07 -06:00
Pavel Begunkov
27a9d66fec 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>
2022-07-24 18:39:14 -06:00
Jens Axboe
d9b57aa3cf io_uring: move opcode table to opdef.c
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: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:12 -06:00