Commit Graph

28 Commits

Author SHA1 Message Date
Jens Axboe
c43203154d io_uring/register: move io_uring_register(2) related code to register.c
Most of this code is basically self contained, move it out of the core
io_uring file to bring a bit more separation to the registration related
bits. This moves another ~10% of the code into register.c.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-12-19 08:54:20 -07:00
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
Pavel Begunkov
eb42cebb2c io_uring: add zc notification infrastructure
Add internal part of send zerocopy notifications. There are two main
structures, the first one is struct io_notif, which carries inside
struct ubuf_info and maps 1:1 to it. io_uring will be binding a number
of zerocopy send requests to it and ask to complete (aka flush) it. When
flushed and all attached requests and skbs complete, it'll generate one
and only one CQE. There are intended to be passed into the network layer
as struct msghdr::msg_ubuf.

The second concept is notification slots. The userspace will be able to
register an array of slots and subsequently addressing them by the index
in the array. Slots are independent of each other. Each slot can have
only one notifier at a time (called active notifier) but many notifiers
during the lifetime. When active, a notifier not going to post any
completion but the userspace can attach requests to it by specifying
the corresponding slot while issueing send zc requests. Eventually, the
userspace will want to "flush" the notifier losing any way to attach
new requests to it, however it can use the next atomatically added
notifier of this slot or of any other slot.

When the network layer is done with all enqueued skbs attached to a
notifier and doesn't need the specified in them user data, the flushed
notifier will post a CQE.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3ecf54c31a85762bf679b0a432c9f43ecf7e61cc.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:41:06 -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
Jens Axboe
f3b44f92e5 io_uring: move read/write related opcodes to its own file
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:12 -06:00
Jens Axboe
7357298448 io_uring: move rsrc related data, core, and commands
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:12 -06:00
Jens Axboe
3b77495a97 io_uring: split provided buffers handling into its own file
Move both the opcodes related to it, and the internals code dealing with
it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:12 -06:00
Jens Axboe
7aaff708a7 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>
2022-07-24 18:39:12 -06:00
Jens Axboe
329061d3e2 io_uring: move poll handling into its own file
Add a io_poll_issue() rather than export the general task_work locking
and io_issue_sqe(), and put the io_op_defs definition and structure into
a separate header file so that poll can use it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:12 -06:00
Jens Axboe
c9f06aa7de io_uring: move io_uring_task (tctx) helpers into its own file
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:12 -06:00
Jens Axboe
a4ad4f748e io_uring: move fdinfo helpers to its own file
This also means moving a bit more of the fixed file handling to the
filetable side, which makes sense separately too.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:12 -06:00
Jens Axboe
17437f3114 io_uring: move SQPOLL related handling into its own file
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:12 -06:00
Jens Axboe
59915143e8 io_uring: move timeout opcodes and handling into its own file
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:12 -06:00
Jens Axboe
36404b09aa io_uring: move msg_ring into its own file
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:12 -06:00
Jens Axboe
f9ead18c10 io_uring: split network related opcodes into its own file
While at it, convert the handlers to just use io_eopnotsupp_prep()
if CONFIG_NET isn't set.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
e0da14def1 io_uring: move statx handling to its own file
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
a9c210cebe io_uring: move epoll handler to its own file
Would be nice to sort out Kconfig for this and don't even compile
epoll.c if we don't have epoll configured.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
99f15d8d61 io_uring: move uring_cmd handling to its own file
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
cd40cae29e io_uring: split out open/close operations
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
453b329be5 io_uring: separate out file table handling code
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
f4c163dd7d io_uring: split out fadvise/madvise operations
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
0d58472740 io_uring: split out fs related sync/fallocate functions
This splits out sync_file_range, fsync, and fallocate.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
531113bbd5 io_uring: split out splice related operations
This splits out splice and tee support.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
11aeb71406 io_uring: split out filesystem related operations
This splits out renameat, unlinkat, mkdirat, symlinkat, and linkat.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
e28683bdfc io_uring: move nop into its own file
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
5e2a18d93f io_uring: move xattr related opcodes to its own file
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:11 -06:00
Jens Axboe
ed29b0b4fd io_uring: move to separate directory
In preparation for splitting io_uring up a bit, move it into its own
top level directory. It didn't really belong in fs/ anyway, as it's
not a file system only API.

This adds io_uring/ and moves the core files in there, and updates the
MAINTAINERS file for the new location.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:10 -06:00