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3770a42bb8
When we queue requests, we strive to batch as much as possible and also
signal the network stack that more data is about to be sent over a socket
with MSG_SENDPAGE_NOTLAST. This flag looks at the pending requests queued
as well as queue->more_requests that is derived from the block layer
last-in-batch indication.
We set more_request=true when we flush the request directly from
.queue_rq submission context (in nvme_tcp_send_all), however this is
wrongly assuming that no other requests may be queued during the
execution of nvme_tcp_send_all.
Due to this, a race condition may happen where:
1. request X is queued as !last-in-batch
2. request X submission context calls nvme_tcp_send_all directly
3. nvme_tcp_send_all is preempted and schedules to a different cpu
4. request Y is queued as last-in-batch
5. nvme_tcp_send_all context sends request X+Y, however signals for
both MSG_SENDPAGE_NOTLAST because queue->more_requests=true.
==> none of the requests is pushed down to the wire as the network
stack is waiting for more data, both requests timeout.
To fix this, we eliminate queue->more_requests and only rely on
the queue req_list and send_list to be not-empty.
Fixes:
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| .. | ||
| common | ||
| host | ||
| target | ||
| Kconfig | ||
| Makefile | ||