Commit dfb58b17 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring/net: fix overexcessive retries 



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: 3ff1a0d3 ("io_uring: enable managed frags with register buffers")
Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0bc0d5179c665b4ef5c328377c84c7a1f298467e.1661530037.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 581711c4

io_uring/net.c

+1 −1
Original line number Diff line number Diff line
@@ -956,7 +956,7 @@ static int io_sg_from_iter(struct sock *sk, struct sk_buff *skb, 
	shinfo->nr_frags = frag;

	from->bvec += bi.bi_idx;

	from->nr_segs -= bi.bi_idx;

	from->count = bi.bi_size;

	from->count -= copied;

	from->iov_offset = bi.bi_bvec_done;



	skb->data_len += copied;