[PATCH 6.18 19/49] smb: client: port and use the wait_for_credits logic used by server

Greg Kroah-Hartman
2026-02-13T13:52:48Z

From: Stefan Metzmacher <metze@samba.org>

commit bb848d205f7ac0141af52a5acb6dd116d9b71177 upstream.

This simplifies the logic and prepares the use of
smbdirect_send_batch in order to make sure
all messages in a multi fragment send are grouped
together.

We'll add the smbdirect_send_batch processin
in a later patch.

Cc: <stable@vger.kernel.org> # 6.18.x
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>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/smb/client/smbdirect.c | 70 ++++++++++++++++++++++++---------------
1 file changed, 43 insertions(+), 27 deletions(-)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index cfbe8ce0db42..405931ce3978 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -1137,6 +1137,44 @@ static int smbd_post_send(struct smbdirect_socket *sc,
return rc;
}

+static int wait_for_credits(struct smbdirect_socket *sc,
+ wait_queue_head_t *waitq, atomic_t *total_credits,
+ int needed)
+{
+ int ret;
+
+ do {
+ if (atomic_sub_return(needed, total_credits) >= 0)
+ return 0;
+
+ atomic_add(needed, total_credits);
+ ret = wait_event_interruptible(*waitq,
+ atomic_read(total_credits) >= needed ||
+ sc->status != SMBDIRECT_SOCKET_CONNECTED);
+
+ if (sc->status != SMBDIRECT_SOCKET_CONNECTED)
+ return -ENOTCONN;
+ else if (ret < 0)
+ return ret;
+ } while (true);
+}
+
+static int wait_for_send_lcredit(struct smbdirect_socket *sc)
+{
+ return wait_for_credits(sc,
+ &sc->send_io.lcredits.wait_queue,
+ &sc->send_io.lcredits.count,
+ 1);
+}
+
+static int wait_for_send_credits(struct smbdirect_socket *sc)
+{
+ return wait_for_credits(sc,
+ &sc->send_io.credits.wait_queue,
+ &sc->send_io.credits.count,
+ 1);
+}
+
static int smbd_post_send_iter(struct smbdirect_socket *sc,
struct iov_iter *iter,
int *_remaining_data_length)
@@ -1149,41 +1187,19 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
struct smbdirect_data_transfer *packet;
int new_credits = 0;

-wait_lcredit:
- /* Wait for local send credits */
- rc = wait_event_interruptible(sc->send_io.lcredits.wait_queue,
- atomic_read(&sc->send_io.lcredits.count) > 0 ||
- sc->status != SMBDIRECT_SOCKET_CONNECTED);
- if (rc)
- goto err_wait_lcredit;
-
- if (sc->status != SMBDIRECT_SOCKET_CONNECTED) {
- log_outgoing(ERR, "disconnected not sending on wait_credit\n");
+ rc = wait_for_send_lcredit(sc);
+ if (rc) {
+ log_outgoing(ERR, "disconnected not sending on wait_lcredit\n");
rc = -EAGAIN;
goto err_wait_lcredit;
}
- if (unlikely(atomic_dec_return(&sc->send_io.lcredits.count) < 0)) {
- atomic_inc(&sc->send_io.lcredits.count);
- goto wait_lcredit;
- }

-wait_credit:
- /* Wait for send credits. A SMBD packet needs one credit */
- rc = wait_event_interruptible(sc->send_io.credits.wait_queue,
- atomic_read(&sc->send_io.credits.count) > 0 ||
- sc->status != SMBDIRECT_SOCKET_CONNECTED);
- if (rc)
- goto err_wait_credit;
-
- if (sc->status != SMBDIRECT_SOCKET_CONNECTED) {
+ rc = wait_for_send_credits(sc);
+ if (rc) {
log_outgoing(ERR, "disconnected not sending on wait_credit\n");
rc = -EAGAIN;
goto err_wait_credit;
}
- if (unlikely(atomic_dec_return(&sc->send_io.credits.count) < 0)) {
- atomic_inc(&sc->send_io.credits.count);
- goto wait_credit;
- }

request = mempool_alloc(sc->send_io.mem.pool, GFP_KERNEL);
if (!request) {
--
2.53.0