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Message-ID: <7e6f6467-6ac2-3926-9d7b-09f52f751481@kernel.dk>
Date:   Wed, 23 Mar 2022 06:19:03 -0600
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Subject: Re: io_uring_enter() with opcode IORING_OP_RECV ignores MSG_WAITALL
 in msg_flags
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To:     Constantine Gavrilov <CONSTG@il.ibm.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <BYAPR15MB260078EC747F0F0183D1BB1BFA189@BYAPR15MB2600.namprd15.prod.outlook.com>
Cc:     io-uring <io-uring@vger.kernel.org>
From:   Jens Axboe <axboe@kernel.dk>
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On 3/23/22 4:31 AM, Constantine Gavrilov wrote:
> I get partial receives on TCP socket, even though I specify
> MSG_WAITALL with IORING_OP_RECV opcode. Looking at tcpdump in
> wireshark, I see entire reassambled packet (+4k), so it is not a
> disconnect. The MTU is smaller than 4k.
> 
> From the mailing list history, looks like this was discussed before
> and it seems the fix was supposed to be in. Can someone clarify the
> expected behavior?
> 
> I do not think rsvmsg() has this issue.

Do you have a test case? I added the io-uring list, that's the
appropriate forum for this kind of discussion.

-- 
Jens Axboe