linux.git/io_uring/net.c, branch v6.0

io_uring/net: fix zc fixed buf lifetime

2022-09-18T11:07:51+00:00

Notifications usually outlive requests, so we need to pin buffers with
it by assigning a rsrc to it instead of the request.

Fixed: b48c312be05e8 ("io_uring/net: simplify zerocopy send user API")
Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/dd6406ff8a90887f2b36ed6205dac9fda17c1f35.1663366886.git.asml.silence@gmail.com
Reviewed-by: Stefan Metzmacher 
Signed-off-by: Jens Axboe

io_uring/net: copy addr for zc on POLL_FIRST

2022-09-08T14:28:38+00:00

Every time we return from an issue handler and expect the request to be
retried we should also setup it for async exec ourselves. Do that when
we return on IORING_RECVSEND_POLL_FIRST in io_sendzc(), otherwise it'll
re-read the address, which might be a surprise for the userspace.

Fixes: 092aeedb750a9 ("io_uring: allow to pass addr into sendzc")
Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/ab1d0657890d6721339c56d2e161a4bba06f85d0.1662642013.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring/net: simplify zerocopy send user API

2022-09-01T15:13:33+00:00

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 
Link: https://lore.kernel.org/r/95287640ab98fc9417370afb16e310677c63e6ce.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring/notif: remove notif registration

2022-09-01T15:13:33+00:00

We're going to remove the userspace exposed zerocopy notification API,
remove notification registration.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/6ff00b97be99869c386958a990593c9c31cf105b.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring/net: fix overexcessive retries

2022-08-26T16:31:42+00:00

Length parameter of io_sg_from_iter() can be smaller than the iterator's
size, as it's with TCP, so when we set from->count at the end of the
function we truncate the iterator forcing TCP to return preliminary with
a short send. It affects zerocopy sends with large payload sizes and
leads to retries and possible request failures.

Fixes: 3ff1a0d395c00 ("io_uring: enable managed frags with register buffers")
Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/0bc0d5179c665b4ef5c328377c84c7a1f298467e.1661530037.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring/net: save address for sendzc async execution

2022-08-25T13:52:30+00:00

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 
Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/d7512d7aa9abcd36e9afe1a4d292a24cb2d157e5.1661342812.git.asml.silence@gmail.com
[axboe: fold in incremental fix]
Signed-off-by: Jens Axboe

io_uring/net: fix indentation

2022-08-24T14:57:15+00:00

Fix up indentation before we get complaints from tooling.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/bd5754e3764215ccd7fb04cd636ea9167aaa275d.1661342812.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring/net: fix zc send link failing

2022-08-24T14:57:00+00:00

Failed requests should be marked with req_set_fail(), so links and cqe
skipping work correctly, which is missing in io_sendzc(). Note,
io_sendzc() return IOU_OK on failure, so the core code won't do the
cleanup for us.

Fixes: 06a5464be84e4 ("io_uring: wire send zc request type")
Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/e47d46fda9db30154ce66a549bb0d3380b780520.1661342812.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring/net: use right helpers for async_data

2022-08-18T13:27:20+00:00

There is another spot where we check ->async_data directly instead of
using req_has_async_data(), which is the way to do it, fix it up.

Fixes: 43e0bbbd0b0e3 ("io_uring: add netmsg cache")
Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/42f33b9a81dd6ae65dda92f0372b0ff82d548517.1660822636.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring/net: improve zc addr import error handling

2022-08-16T03:34:00+00:00

We may account memory to a memcg of a request that didn't even got to
the network layer. It's not a bug as it'll be routinely cleaned up on
flush, but it might be confusing for the userspace.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/b8aae61f4c3ddc4da97c1da876bb73871f352d50.1660566179.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe