io_uring/kbuf: advance head when a pickup empties the buffer ring

io_ring_buffers_peek() flags the request with REQ_F_BL_EMPTY if the
buffers it picked were the last ones available, comparing head to tail.
When the loop breaks because max_len was exhausted the buffer was picked,
but head is left pointing at it, so the flag isn't set if it was the last
buffer. A bundle receive then retries, finds no buffer, and the request,
which has received data, is marked as failed on account of the -ENOBUFS.
That severs a link, and ends a multishot.

Fixes: 35c8711c8fc4 ("io_uring/kbuf: add helpers for getting/peeking multiple buffers")
Signed-off-by: Yichong Chen <chenyichong@uniontech.com>
Link: https://patch.msgid.link/20261023091711.83481-1-chenyichong@uniontech.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

0 files changed, 0 insertions, 0 deletions