From: Stefan Metzmacher <metze@samba.org>
Date: Fri, 17 Oct 2025 13:15:05 +0000 (+0200)
Subject: smb: smbdirect: introduce smbdirect_connection_grant_recv_credits()
X-Git-Tag: v7.1-rc1~128^2~107
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=3514195010828078173dd0608ba04340b718892f;p=thirdparty%2Fkernel%2Flinux.git

smb: smbdirect: introduce smbdirect_connection_grant_recv_credits()

This is basically a copy of manage_credits_prior_sending() in the client
and the server.

It will replace both versions in future.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
---

diff --git a/fs/smb/common/smbdirect/smbdirect_connection.c b/fs/smb/common/smbdirect/smbdirect_connection.c
index 0eebc7f336f5a..40d830c58f195 100644
--- a/fs/smb/common/smbdirect/smbdirect_connection.c
+++ b/fs/smb/common/smbdirect/smbdirect_connection.c
@@ -688,6 +688,44 @@ static void smbdirect_connection_idle_timer_work(struct work_struct *work)
 	queue_work(sc->workqueue, &sc->idle.immediate_work);
 }
 
+__maybe_unused /* this is temporary while this file is included in others */
+static u16 smbdirect_connection_grant_recv_credits(struct smbdirect_socket *sc)
+{
+	int missing;
+	int available;
+	int new_credits;
+
+	if (atomic_read(&sc->recv_io.credits.count) >= sc->recv_io.credits.target)
+		return 0;
+
+	missing = (int)sc->recv_io.credits.target - atomic_read(&sc->recv_io.credits.count);
+	available = atomic_xchg(&sc->recv_io.credits.available, 0);
+	new_credits = min3((int)U16_MAX, missing, available);
+	if (new_credits <= 0) {
+		/*
+		 * If credits are available, but not granted
+		 * we need to re-add them again.
+		 */
+		if (available)
+			atomic_add(available, &sc->recv_io.credits.available);
+		return 0;
+	}
+
+	if (new_credits < available) {
+		/*
+		 * Readd the remaining available again.
+		 */
+		available -= new_credits;
+		atomic_add(available, &sc->recv_io.credits.available);
+	}
+
+	/*
+	 * Remember we granted the credits
+	 */
+	atomic_add(new_credits, &sc->recv_io.credits.count);
+	return new_credits;
+}
+
 __maybe_unused /* this is temporary while this file is included in others */
 static void smbdirect_connection_send_io_done(struct ib_cq *cq, struct ib_wc *wc)
 {