6.15-stable review patch. If anyone has any objections, please let me know.
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From: Hannes Reinecke hare@kernel.org
[ Upstream commit f42d4796ee100fade86086d1cf98537fb4d326c8 ]
When the socket is busy processing nvme_tcp_try_recv() might return -EAGAIN, but this doesn't automatically imply that the sending side is blocked, too. So check if there are pending requests once nvme_tcp_try_recv() returns -EAGAIN and continue with the sending loop to avoid I/O stalls.
Signed-off-by: Hannes Reinecke hare@kernel.org Acked-by: Chris Leech cleech@redhat.com Reviewed-by: Sagi Grimberg sagi@grimberg.me Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/tcp.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 947fac9128b30..9f4f6464dee04 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -1348,7 +1348,7 @@ static int nvme_tcp_try_recv(struct nvme_tcp_queue *queue) queue->nr_cqe = 0; consumed = sock->ops->read_sock(sk, &rd_desc, nvme_tcp_recv_skb); release_sock(sk); - return consumed; + return consumed == -EAGAIN ? 0 : consumed; }
static void nvme_tcp_io_work(struct work_struct *w) @@ -1376,6 +1376,11 @@ static void nvme_tcp_io_work(struct work_struct *w) else if (unlikely(result < 0)) return;
+ /* did we get some space after spending time in recv? */ + if (nvme_tcp_queue_has_pending(queue) && + sk_stream_is_writeable(queue->sock->sk)) + pending = true; + if (!pending || !queue->rd_enabled) return;