From: Pavel Begunkov <asml.silence@gmail.com>
To: Jens Axboe <axboe@kernel.dk>, io-uring@vger.kernel.org
Cc: constantine.gavrilov@gmail.com, stable@vger.kernel.org
Subject: Re: [PATCH 1/2] io_uring: ensure recv and recvmsg handle MSG_WAITALL correctly
Date: Wed, 23 Mar 2022 20:13:09 +0000 [thread overview]
Message-ID: <64197456-87f2-e780-186d-272e06ae223b@gmail.com> (raw)
In-Reply-To: <20220323153947.142692-2-axboe@kernel.dk>
On 3/23/22 15:39, Jens Axboe wrote:
> We currently don't attempt to get the full asked for length even if
> MSG_WAITALL is set, if we get a partial receive. If we do see a partial
> receive, then just note how many bytes we did and return -EAGAIN to
> get it retried.
>
> The iov is advanced appropriately for the vector based case, and we
> manually bump the buffer and remainder for the non-vector case.
How datagrams work with MSG_WAITALL? I highly doubt it coalesces 2+
packets to satisfy the length requirement (e.g. because it may move
the address back into the userspace). I'm mainly afraid about
breaking io_uring users who are using the flag just to fail links
when there is not enough data in a packet.
--
Pavel Begunkov
next prev parent reply other threads:[~2022-03-23 20:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-23 15:39 [PATCHSET 0/2] Fix MSG_WAITALL for IORING_OP_RECV/RECVMSG Jens Axboe
2022-03-23 15:39 ` [PATCH 1/2] io_uring: ensure recv and recvmsg handle MSG_WAITALL correctly Jens Axboe
2022-03-23 20:13 ` Pavel Begunkov [this message]
2022-03-23 20:15 ` Jens Axboe
2022-03-23 20:45 ` Constantine Gavrilov
2022-03-23 20:52 ` Pavel Begunkov
2022-03-23 21:24 ` Jens Axboe
2022-03-23 15:39 ` [PATCH 2/2] io_uring: add flag for disabling provided buffer recycling Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2022-03-23 22:41 [PATCHSET v2 0/2] Fix MSG_WAITALL for IORING_OP_RECV/RECVMSG Jens Axboe
2022-03-23 22:41 ` [PATCH 1/2] io_uring: ensure recv and recvmsg handle MSG_WAITALL correctly Jens Axboe
2022-03-24 0:32 ` Stefan Metzmacher
2022-03-24 0:35 ` Jens Axboe
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