From 8106978d400cc88a99fb94927afe8fec7391ca3e Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Thu, 22 Jan 2026 18:16:44 +0100 Subject: [PATCH] smb: server: let recv_done() queue a refill when the peer is low on credits In captures I saw that Windows was granting 191 credits in a batch when its peer posted a lot of messages. We are asking for a credit target of 255 and 191 is 252*3/4. So we also use that logic in order to fill the recv buffers available to the peer. Fixes: a7eef6144c97 ("smb: server: queue post_recv_credits_work in put_recvmsg() and avoid count_avail_recvmsg") Cc: # 6.18.x Cc: Namjae Jeon Cc: Steve French Cc: Tom Talpey Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Signed-off-by: Stefan Metzmacher Acked-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/transport_rdma.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/smb/server/transport_rdma.c b/fs/smb/server/transport_rdma.c index c66f237dc106b..4a473df1f2b3a 100644 --- a/fs/smb/server/transport_rdma.c +++ b/fs/smb/server/transport_rdma.c @@ -644,6 +644,7 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc) struct smbdirect_data_transfer *data_transfer = (struct smbdirect_data_transfer *)recvmsg->packet; u32 remaining_data_length, data_offset, data_length; + int current_recv_credits; u16 old_recv_credit_target; if (wc->byte_len < @@ -682,7 +683,7 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc) } atomic_dec(&sc->recv_io.posted.count); - atomic_dec(&sc->recv_io.credits.count); + current_recv_credits = atomic_dec_return(&sc->recv_io.credits.count); old_recv_credit_target = sc->recv_io.credits.target; sc->recv_io.credits.target = @@ -702,7 +703,8 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc) wake_up(&sc->send_io.credits.wait_queue); if (data_length) { - if (sc->recv_io.credits.target > old_recv_credit_target) + if (current_recv_credits <= (sc->recv_io.credits.target / 4) || + sc->recv_io.credits.target > old_recv_credit_target) queue_work(sc->workqueue, &sc->recv_io.posted.refill_work); enqueue_reassembly(sc, recvmsg, (int)data_length); -- 2.47.3