[PATCH 6.18 07/49] smb: smbdirect: introduce smbdirect_socket.recv_io.credits.available

[PATCH 6.18 07/49] smb: smbdirect: introduce smbdirect_socket.recv_io.credits.available

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 6e3c5052f9686192e178806e017b7377155f4bab upstream.

The logic off managing recv credits by counting posted recv_io and
granted credits is racy.

That's because the peer might already consumed a credit,
but between receiving the incoming recv at the hardware
and processing the completion in the 'recv_done' functions
we likely have a window where we grant credits, which
don't really exist.

So we better have a decicated counter for the
available credits, which will be incremented
when we posted new recv buffers and drained when
we grant the credits to the peer.

Fixes: 5fb9b459b368 ("smb: client: count the number of posted recv_io messages in order to calculated credits")
Fixes: 89b021a72663 ("smb: server: manage recv credits by counting posted recv_io and granted credits")
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>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/common/smbdirect/smbdirect_socket.h |    2 ++
 1 file changed, 2 insertions(+)

--- a/fs/smb/common/smbdirect/smbdirect_socket.h
+++ b/fs/smb/common/smbdirect/smbdirect_socket.h
@@ -231,6 +231,7 @@ struct smbdirect_socket {
 		 */
 		struct {
 			u16 target;
+			atomic_t available;
 			atomic_t count;
 		} credits;
 
@@ -375,6 +376,7 @@ static __always_inline void smbdirect_so
 	INIT_WORK(&sc->recv_io.posted.refill_work, __smbdirect_socket_disabled_work);
 	disable_work_sync(&sc->recv_io.posted.refill_work);
 
+	atomic_set(&sc->recv_io.credits.available, 0);
 	atomic_set(&sc->recv_io.credits.count, 0);
 
 	INIT_LIST_HEAD(&sc->recv_io.reassembly.list);

[PATCH 6.18 08/49] smb: smbdirect: introduce smbdirect_socket.send_io.bcredits.*

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 8e94268b21c8235d430ce1aa6dc0b15952744b9b upstream.

It turns out that our code will corrupt the stream of
reassabled data transfer messages when we trigger an
immendiate (empty) send.

In order to fix this we'll have a single 'batch' credit per
connection. And code getting that credit is free to use
as much messages until remaining_length reaches 0, then
the batch credit it given back and the next logical send can
happen.

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>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/common/smbdirect/smbdirect_socket.h |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

--- a/fs/smb/common/smbdirect/smbdirect_socket.h
+++ b/fs/smb/common/smbdirect/smbdirect_socket.h
@@ -155,6 +155,17 @@ struct smbdirect_socket {
 		} mem;
 
 		/*
+		 * This is a coordination for smbdirect_send_batch.
+		 *
+		 * There's only one possible credit, which means
+		 * only one instance is running at a time.
+		 */
+		struct {
+			atomic_t count;
+			wait_queue_head_t wait_queue;
+		} bcredits;
+
+		/*
 		 * The local credit state for ib_post_send()
 		 */
 		struct {
@@ -359,6 +370,9 @@ static __always_inline void smbdirect_so
 	INIT_DELAYED_WORK(&sc->idle.timer_work, __smbdirect_socket_disabled_work);
 	disable_delayed_work_sync(&sc->idle.timer_work);
 
+	atomic_set(&sc->send_io.bcredits.count, 0);
+	init_waitqueue_head(&sc->send_io.bcredits.wait_queue);
+
 	atomic_set(&sc->send_io.lcredits.count, 0);
 	init_waitqueue_head(&sc->send_io.lcredits.wait_queue);
 
@@ -473,6 +487,8 @@ struct smbdirect_send_batch {
 	 */
 	bool need_invalidate_rkey;
 	u32 remote_key;
+
+	int credit;
 };
 
 struct smbdirect_recv_io {

[PATCH 6.18 09/49] smb: server: make use of smbdirect_socket.recv_io.credits.available

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 26ad87a2cfb8c1384620d1693a166ed87303046e upstream.

The logic off managing recv credits by counting posted recv_io and
granted credits is racy.

That's because the peer might already consumed a credit,
but between receiving the incoming recv at the hardware
and processing the completion in the 'recv_done' functions
we likely have a window where we grant credits, which
don't really exist.

So we better have a decicated counter for the
available credits, which will be incremented
when we posted new recv buffers and drained when
we grant the credits to the peer.

This fixes regression Namjae reported with
the 6.18 release.

Fixes: 89b021a72663 ("smb: server: manage recv credits by counting posted recv_io and granted credits")
Cc: <stable@vger.kernel.org> # 6.18.x
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/server/transport_rdma.c |   30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

--- a/fs/smb/server/transport_rdma.c
+++ b/fs/smb/server/transport_rdma.c
@@ -926,6 +926,8 @@ static void smb_direct_post_recv_credits
 		}
 	}
 
+	atomic_add(credits, &sc->recv_io.credits.available);
+
 	if (credits)
 		queue_work(sc->workqueue, &sc->idle.immediate_work);
 }
@@ -972,19 +974,37 @@ static void send_done(struct ib_cq *cq,
 
 static int manage_credits_prior_sending(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;
 
-	new_credits = atomic_read(&sc->recv_io.posted.count);
-	if (new_credits == 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 = (u16)min3(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;
+	}
 
-	new_credits -= atomic_read(&sc->recv_io.credits.count);
-	if (new_credits <= 0)
-		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;
 }

[PATCH 6.18 10/49] smb: server: let recv_done() queue a refill when the peer is low on credits

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 8106978d400cc88a99fb94927afe8fec7391ca3e upstream.

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: <stable@vger.kernel.org> # 6.18.x
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/server/transport_rdma.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/fs/smb/server/transport_rdma.c
+++ b/fs/smb/server/transport_rdma.c
@@ -661,6 +661,7 @@ static void recv_done(struct ib_cq *cq,
 		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 <
@@ -699,7 +700,7 @@ static void recv_done(struct ib_cq *cq,
 		}
 
 		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 =
@@ -719,7 +720,8 @@ static void recv_done(struct ib_cq *cq,
 			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);

[PATCH 6.18 11/49] smb: server: make use of smbdirect_socket.send_io.bcredits

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 34abd408c8ba24d7c97bd02ba874d8c714f49db1 upstream.

It turns out that our code will corrupt the stream of
reassabled data transfer messages when we trigger an
immendiate (empty) send.

In order to fix this we'll have a single 'batch' credit per
connection. And code getting that credit is free to use
as much messages until remaining_length reaches 0, then
the batch credit it given back and the next logical send can
happen.

Cc: <stable@vger.kernel.org> # 6.18.x
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/server/transport_rdma.c |   53 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 51 insertions(+), 2 deletions(-)

--- a/fs/smb/server/transport_rdma.c
+++ b/fs/smb/server/transport_rdma.c
@@ -221,6 +221,7 @@ static void smb_direct_disconnect_wake_u
 	 * in order to notice the broken connection.
 	 */
 	wake_up_all(&sc->status_wait);
+	wake_up_all(&sc->send_io.bcredits.wait_queue);
 	wake_up_all(&sc->send_io.lcredits.wait_queue);
 	wake_up_all(&sc->send_io.credits.wait_queue);
 	wake_up_all(&sc->send_io.pending.zero_wait_queue);
@@ -1050,6 +1051,7 @@ static void smb_direct_send_ctx_init(str
 	send_ctx->wr_cnt = 0;
 	send_ctx->need_invalidate_rkey = need_invalidate_rkey;
 	send_ctx->remote_key = remote_key;
+	send_ctx->credit = 0;
 }
 
 static int smb_direct_flush_send_list(struct smbdirect_socket *sc,
@@ -1057,10 +1059,10 @@ static int smb_direct_flush_send_list(st
 				      bool is_last)
 {
 	struct smbdirect_send_io *first, *last;
-	int ret;
+	int ret = 0;
 
 	if (list_empty(&send_ctx->msg_list))
-		return 0;
+		goto release_credit;
 
 	first = list_first_entry(&send_ctx->msg_list,
 				 struct smbdirect_send_io,
@@ -1102,6 +1104,13 @@ static int smb_direct_flush_send_list(st
 		smb_direct_free_sendmsg(sc, last);
 	}
 
+release_credit:
+	if (is_last && !ret && send_ctx->credit) {
+		atomic_add(send_ctx->credit, &sc->send_io.bcredits.count);
+		send_ctx->credit = 0;
+		wake_up(&sc->send_io.bcredits.wait_queue);
+	}
+
 	return ret;
 }
 
@@ -1127,6 +1136,25 @@ static int wait_for_credits(struct smbdi
 	} while (true);
 }
 
+static int wait_for_send_bcredit(struct smbdirect_socket *sc,
+				 struct smbdirect_send_batch *send_ctx)
+{
+	int ret;
+
+	if (send_ctx->credit)
+		return 0;
+
+	ret = wait_for_credits(sc,
+			       &sc->send_io.bcredits.wait_queue,
+			       &sc->send_io.bcredits.count,
+			       1);
+	if (ret)
+		return ret;
+
+	send_ctx->credit = 1;
+	return 0;
+}
+
 static int wait_for_send_lcredit(struct smbdirect_socket *sc,
 				 struct smbdirect_send_batch *send_ctx)
 {
@@ -1328,6 +1356,16 @@ static int smb_direct_post_send_data(str
 	struct smbdirect_send_io *msg;
 	int data_length;
 	struct scatterlist sg[SMBDIRECT_SEND_IO_MAX_SGE - 1];
+	struct smbdirect_send_batch _send_ctx;
+
+	if (!send_ctx) {
+		smb_direct_send_ctx_init(&_send_ctx, false, 0);
+		send_ctx = &_send_ctx;
+	}
+
+	ret = wait_for_send_bcredit(sc, send_ctx);
+	if (ret)
+		goto bcredit_failed;
 
 	ret = wait_for_send_lcredit(sc, send_ctx);
 	if (ret)
@@ -1380,6 +1418,13 @@ static int smb_direct_post_send_data(str
 	ret = post_sendmsg(sc, send_ctx, msg);
 	if (ret)
 		goto err;
+
+	if (send_ctx == &_send_ctx) {
+		ret = smb_direct_flush_send_list(sc, send_ctx, true);
+		if (ret)
+			goto err;
+	}
+
 	return 0;
 err:
 	smb_direct_free_sendmsg(sc, msg);
@@ -1388,6 +1433,9 @@ header_failed:
 credit_failed:
 	atomic_inc(&sc->send_io.lcredits.count);
 lcredit_failed:
+	atomic_add(send_ctx->credit, &sc->send_io.bcredits.count);
+	send_ctx->credit = 0;
+bcredit_failed:
 	return ret;
 }
 
@@ -1849,6 +1897,7 @@ static int smb_direct_send_negotiate_res
 		resp->max_fragmented_size =
 				cpu_to_le32(sp->max_fragmented_recv_size);
 
+		atomic_set(&sc->send_io.bcredits.count, 1);
 		sc->recv_io.expected = SMBDIRECT_EXPECT_DATA_TRANSFER;
 		sc->status = SMBDIRECT_SOCKET_CONNECTED;
 	}

[PATCH 6.18 12/49] smb: server: fix last send credit problem causing disconnects

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 8cf2bbac6281434065f5f3aeab19c9c08ff755a2 upstream.

When we are about to use the last send credit that was
granted to us by the peer, we need to wait until
we are ourself able to grant at least one credit
to the peer. Otherwise it might not be possible
for the peer to grant more credits.

The following sections in MS-SMBD are related to this:

3.1.5.1 Sending Upper Layer Messages
...
If Connection.SendCredits is 1 and the CreditsGranted field of the
message is 0, stop processing.
...

3.1.5.9 Managing Credits Prior to Sending
...
If Connection.ReceiveCredits is zero, or if Connection.SendCredits is
one and the Connection.SendQueue is not empty, the sender MUST allocate
and post at least one receive of size Connection.MaxReceiveSize and MUST
increment Connection.ReceiveCredits by the number allocated and posted.
If no receives are posted, the processing MUST return a value of zero to
indicate to the caller that no Send message can be currently performed.
...

This problem was found by running this on Windows 2025
against ksmbd with required smb signing:
'frametest.exe -r 4k -t 20 -n 2000' after
'frametest.exe -w 4k -t 20 -n 2000'.

Link: https://lore.kernel.org/linux-cifs/b58fa352-2386-4145-b42e-9b4b1d484e17@samba.org/
Cc: <stable@vger.kernel.org> # 6.18.x
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/server/transport_rdma.c |   32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

--- a/fs/smb/server/transport_rdma.c
+++ b/fs/smb/server/transport_rdma.c
@@ -931,6 +931,15 @@ static void smb_direct_post_recv_credits
 
 	atomic_add(credits, &sc->recv_io.credits.available);
 
+	/*
+	 * If the last send credit is waiting for credits
+	 * it can grant we need to wake it up
+	 */
+	if (credits &&
+	    atomic_read(&sc->send_io.bcredits.count) == 0 &&
+	    atomic_read(&sc->send_io.credits.count) == 0)
+		wake_up(&sc->send_io.credits.wait_queue);
+
 	if (credits)
 		queue_work(sc->workqueue, &sc->idle.immediate_work);
 }
@@ -1204,6 +1213,7 @@ static int calc_rw_credits(struct smbdir
 
 static int smb_direct_create_header(struct smbdirect_socket *sc,
 				    int size, int remaining_data_length,
+				    int new_credits,
 				    struct smbdirect_send_io **sendmsg_out)
 {
 	struct smbdirect_socket_parameters *sp = &sc->parameters;
@@ -1219,7 +1229,7 @@ static int smb_direct_create_header(stru
 	/* Fill in the packet header */
 	packet = (struct smbdirect_data_transfer *)sendmsg->packet;
 	packet->credits_requested = cpu_to_le16(sp->send_credit_target);
-	packet->credits_granted = cpu_to_le16(manage_credits_prior_sending(sc));
+	packet->credits_granted = cpu_to_le16(new_credits);
 
 	packet->flags = 0;
 	if (manage_keep_alive_before_sending(sc))
@@ -1357,6 +1367,7 @@ static int smb_direct_post_send_data(str
 	int data_length;
 	struct scatterlist sg[SMBDIRECT_SEND_IO_MAX_SGE - 1];
 	struct smbdirect_send_batch _send_ctx;
+	int new_credits;
 
 	if (!send_ctx) {
 		smb_direct_send_ctx_init(&_send_ctx, false, 0);
@@ -1375,12 +1386,29 @@ static int smb_direct_post_send_data(str
 	if (ret)
 		goto credit_failed;
 
+	new_credits = manage_credits_prior_sending(sc);
+	if (new_credits == 0 &&
+	    atomic_read(&sc->send_io.credits.count) == 0 &&
+	    atomic_read(&sc->recv_io.credits.count) == 0) {
+		queue_work(sc->workqueue, &sc->recv_io.posted.refill_work);
+		ret = wait_event_interruptible(sc->send_io.credits.wait_queue,
+					       atomic_read(&sc->send_io.credits.count) >= 1 ||
+					       atomic_read(&sc->recv_io.credits.available) >= 1 ||
+					       sc->status != SMBDIRECT_SOCKET_CONNECTED);
+		if (sc->status != SMBDIRECT_SOCKET_CONNECTED)
+			ret = -ENOTCONN;
+		if (ret < 0)
+			goto credit_failed;
+
+		new_credits = manage_credits_prior_sending(sc);
+	}
+
 	data_length = 0;
 	for (i = 0; i < niov; i++)
 		data_length += iov[i].iov_len;
 
 	ret = smb_direct_create_header(sc, data_length, remaining_data_length,
-				       &msg);
+				       new_credits, &msg);
 	if (ret)
 		goto header_failed;
 

[PATCH 6.18 13/49] smb: server: let send_done handle a completion without IB_SEND_SIGNALED

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 9da82dc73cb03e85d716a2609364572367a5ff47 upstream.

With smbdirect_send_batch processing we likely have requests without
IB_SEND_SIGNALED, which will be destroyed in the final request
that has IB_SEND_SIGNALED set.

If the connection is broken all requests are signaled
even without explicit IB_SEND_SIGNALED.

Cc: <stable@vger.kernel.org> # 6.18.x
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/server/transport_rdma.c |   26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

--- a/fs/smb/server/transport_rdma.c
+++ b/fs/smb/server/transport_rdma.c
@@ -957,6 +957,31 @@ static void send_done(struct ib_cq *cq,
 		    ib_wc_status_msg(wc->status), wc->status,
 		    wc->opcode);
 
+	if (unlikely(!(sendmsg->wr.send_flags & IB_SEND_SIGNALED))) {
+		/*
+		 * This happens when smbdirect_send_io is a sibling
+		 * before the final message, it is signaled on
+		 * error anyway, so we need to skip
+		 * smbdirect_connection_free_send_io here,
+		 * otherwise is will destroy the memory
+		 * of the siblings too, which will cause
+		 * use after free problems for the others
+		 * triggered from ib_drain_qp().
+		 */
+		if (wc->status != IB_WC_SUCCESS)
+			goto skip_free;
+
+		/*
+		 * This should not happen!
+		 * But we better just close the
+		 * connection...
+		 */
+		pr_err("unexpected send completion wc->status=%s (%d) wc->opcode=%d\n",
+		       ib_wc_status_msg(wc->status), wc->status, wc->opcode);
+		smb_direct_disconnect_rdma_connection(sc);
+		return;
+	}
+
 	/*
 	 * Free possible siblings and then the main send_io
 	 */
@@ -970,6 +995,7 @@ static void send_done(struct ib_cq *cq,
 	lcredits += 1;
 
 	if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_SEND) {
+skip_free:
 		pr_err("Send error. status='%s (%d)', opcode=%d\n",
 		       ib_wc_status_msg(wc->status), wc->status,
 		       wc->opcode);

[PATCH 6.18 14/49] smb: client: make use of smbdirect_socket.recv_io.credits.available

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 9911b1ed187a770a43950bf51f340ad4b7beecba upstream.

The logic off managing recv credits by counting posted recv_io and
granted credits is racy.

That's because the peer might already consumed a credit,
but between receiving the incoming recv at the hardware
and processing the completion in the 'recv_done' functions
we likely have a window where we grant credits, which
don't really exist.

So we better have a decicated counter for the
available credits, which will be incremented
when we posted new recv buffers and drained when
we grant the credits to the peer.

Fixes: 5fb9b459b368 ("smb: client: count the number of posted recv_io messages in order to calculated credits")
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 |   34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -618,6 +618,7 @@ static void smbd_post_send_credits(struc
 	struct smbdirect_recv_io *response;
 	struct smbdirect_socket *sc =
 		container_of(work, struct smbdirect_socket, recv_io.posted.refill_work);
+	int posted = 0;
 
 	if (sc->status != SMBDIRECT_SOCKET_CONNECTED) {
 		return;
@@ -640,9 +641,12 @@ static void smbd_post_send_credits(struc
 			}
 
 			atomic_inc(&sc->recv_io.posted.count);
+			posted += 1;
 		}
 	}
 
+	atomic_add(posted, &sc->recv_io.credits.available);
+
 	/* Promptly send an immediate packet as defined in [MS-SMBD] 3.1.1.1 */
 	if (atomic_read(&sc->recv_io.credits.count) <
 		sc->recv_io.credits.target - 1) {
@@ -1033,19 +1037,38 @@ dma_mapping_failed:
  */
 static int manage_credits_prior_sending(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;
 
-	new_credits = atomic_read(&sc->recv_io.posted.count);
-	if (new_credits == 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 = (u16)min3(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;
+	}
 
-	new_credits -= atomic_read(&sc->recv_io.credits.count);
-	if (new_credits <= 0)
-		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;
 }
 
@@ -1217,7 +1240,6 @@ wait_credit:
 	packet->credits_requested = cpu_to_le16(sp->send_credit_target);
 
 	new_credits = manage_credits_prior_sending(sc);
-	atomic_add(new_credits, &sc->recv_io.credits.count);
 	packet->credits_granted = cpu_to_le16(new_credits);
 
 	packet->flags = 0;

[PATCH 6.18 15/49] smb: client: let recv_done() queue a refill when the peer is low on credits

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit defb3c05fee94b296eebe05aaea16d2664b00252 upstream.

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: 02548c477a90 ("smb: client: queue post_recv_credits_work also if the peer raises the credit target")
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 |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -663,6 +663,7 @@ static void recv_done(struct ib_cq *cq,
 		container_of(wc->wr_cqe, struct smbdirect_recv_io, cqe);
 	struct smbdirect_socket *sc = response->socket;
 	struct smbdirect_socket_parameters *sp = &sc->parameters;
+	int current_recv_credits;
 	u16 old_recv_credit_target;
 	u32 data_offset = 0;
 	u32 data_length = 0;
@@ -747,7 +748,8 @@ static void recv_done(struct ib_cq *cq,
 		}
 
 		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 =
 			le16_to_cpu(data_transfer->credits_requested);
@@ -783,7 +785,8 @@ static void recv_done(struct ib_cq *cq,
 		 * reassembly queue and wake up the reading thread
 		 */
 		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, response, data_length);

[PATCH 6.18 16/49] smb: client: let smbd_post_send() make use of request->wr

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit bf1656e12a9db2add716c7fb57b56967f69599fa upstream.

We don't need a stack variable in addition.

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 | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index 61693b4a83fc..f2ae35a9f047 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -1105,7 +1105,6 @@ static int manage_keep_alive_before_sending(struct smbdirect_socket *sc)
 static int smbd_post_send(struct smbdirect_socket *sc,
 		struct smbdirect_send_io *request)
 {
-	struct ib_send_wr send_wr;
 	int rc, i;
 
 	for (i = 0; i < request->num_sge; i++) {
@@ -1121,14 +1120,14 @@ static int smbd_post_send(struct smbdirect_socket *sc,
 
 	request->cqe.done = send_done;
 
-	send_wr.next = NULL;
-	send_wr.wr_cqe = &request->cqe;
-	send_wr.sg_list = request->sge;
-	send_wr.num_sge = request->num_sge;
-	send_wr.opcode = IB_WR_SEND;
-	send_wr.send_flags = IB_SEND_SIGNALED;
+	request->wr.next = NULL;
+	request->wr.wr_cqe = &request->cqe;
+	request->wr.sg_list = request->sge;
+	request->wr.num_sge = request->num_sge;
+	request->wr.opcode = IB_WR_SEND;
+	request->wr.send_flags = IB_SEND_SIGNALED;
 
-	rc = ib_post_send(sc->ib.qp, &send_wr, NULL);
+	rc = ib_post_send(sc->ib.qp, &request->wr, NULL);
 	if (rc) {
 		log_rdma_send(ERR, "ib_post_send failed rc=%d\n", rc);
 		smbd_disconnect_rdma_connection(sc);
-- 
2.53.0

[PATCH 6.18 17/49] smb: client: remove pointless sc->recv_io.credits.count rollback

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 6858531e5e8d68828eec349989cefce3f45a487f upstream.

We either reach this code path before we call
new_credits = manage_credits_prior_sending(sc),
which means new_credits is still 0
or the connection is already broken as
smbd_post_send() already called
smbd_disconnect_rdma_connection().

This will also simplify further changes.

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 | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index f2ae35a9f047..c9fcd35e0c77 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -1288,9 +1288,6 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 					    DMA_TO_DEVICE);
 	mempool_free(request, sc->send_io.mem.pool);
 
-	/* roll back the granted receive credits */
-	atomic_sub(new_credits, &sc->recv_io.credits.count);
-
 err_alloc:
 	atomic_inc(&sc->send_io.credits.count);
 	wake_up(&sc->send_io.credits.wait_queue);
-- 
2.53.0

[PATCH 6.18 18/49] smb: client: remove pointless sc->send_io.pending handling in smbd_post_send_iter()

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 8bfe3fd33f36b987c8200b112646732b5f5cd8b3 upstream.

If we reach this the connection is already broken as
smbd_post_send() already called
smbd_disconnect_rdma_connection().

This will also simplify further changes.

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 | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index c9fcd35e0c77..cfbe8ce0db42 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -1274,11 +1274,6 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 	if (!rc)
 		return 0;
 
-	if (atomic_dec_and_test(&sc->send_io.pending.count))
-		wake_up(&sc->send_io.pending.zero_wait_queue);
-
-	wake_up(&sc->send_io.pending.dec_wait_queue);
-
 err_dma:
 	for (i = 0; i < request->num_sge; i++)
 		if (request->sge[i].addr)
-- 
2.53.0

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

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

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

[PATCH 6.18 20/49] smb: client: split out smbd_ib_post_send()

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit bf30515caec590316e0d08208e4252eed4c160df upstream.

This is like smb_direct_post_send() in the server
and will simplify porting the smbdirect_send_batch
and credit related logic from the server.

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 |   33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)

--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -1101,11 +1101,26 @@ static int manage_keep_alive_before_send
 	return 0;
 }
 
+static int smbd_ib_post_send(struct smbdirect_socket *sc,
+			     struct ib_send_wr *wr)
+{
+	int ret;
+
+	atomic_inc(&sc->send_io.pending.count);
+	ret = ib_post_send(sc->ib.qp, wr, NULL);
+	if (ret) {
+		pr_err("failed to post send: %d\n", ret);
+		smbd_disconnect_rdma_connection(sc);
+		ret = -EAGAIN;
+	}
+	return ret;
+}
+
 /* Post the send request */
 static int smbd_post_send(struct smbdirect_socket *sc,
 		struct smbdirect_send_io *request)
 {
-	int rc, i;
+	int i;
 
 	for (i = 0; i < request->num_sge; i++) {
 		log_rdma_send(INFO,
@@ -1126,15 +1141,7 @@ static int smbd_post_send(struct smbdire
 	request->wr.num_sge = request->num_sge;
 	request->wr.opcode = IB_WR_SEND;
 	request->wr.send_flags = IB_SEND_SIGNALED;
-
-	rc = ib_post_send(sc->ib.qp, &request->wr, NULL);
-	if (rc) {
-		log_rdma_send(ERR, "ib_post_send failed rc=%d\n", rc);
-		smbd_disconnect_rdma_connection(sc);
-		rc = -EAGAIN;
-	}
-
-	return rc;
+	return smbd_ib_post_send(sc, &request->wr);
 }
 
 static int wait_for_credits(struct smbdirect_socket *sc,
@@ -1280,12 +1287,6 @@ static int smbd_post_send_iter(struct sm
 		     le32_to_cpu(packet->data_length),
 		     le32_to_cpu(packet->remaining_data_length));
 
-	/*
-	 * Now that we got a local and a remote credit
-	 * we add us as pending
-	 */
-	atomic_inc(&sc->send_io.pending.count);
-
 	rc = smbd_post_send(sc, request);
 	if (!rc)
 		return 0;

[PATCH 6.18 21/49] smb: client: introduce and use smbd_{alloc, free}_send_io()

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit dc77da0373529d43175984b390106be2d8f03609 upstream.

This is basically a copy of smb_direct_{alloc,free}_sendmsg()
in the server, with just using ib_dma_unmap_page() in all
cases, which is the same as ib_dma_unmap_single().

We'll use this logic in common code in future.
(I basically backported it from my branch that
as already has everything in common).

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 | 87 ++++++++++++++++++++++++++-------------
 1 file changed, 58 insertions(+), 29 deletions(-)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index 75c0ac9cc65c..6cb40da7e589 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -493,10 +493,54 @@ static inline void *smbdirect_recv_io_payload(struct smbdirect_recv_io *response
 	return (void *)response->packet;
 }
 
+static struct smbdirect_send_io *smbd_alloc_send_io(struct smbdirect_socket *sc)
+{
+	struct smbdirect_send_io *msg;
+
+	msg = mempool_alloc(sc->send_io.mem.pool, GFP_KERNEL);
+	if (!msg)
+		return ERR_PTR(-ENOMEM);
+	msg->socket = sc;
+	INIT_LIST_HEAD(&msg->sibling_list);
+	msg->num_sge = 0;
+
+	return msg;
+}
+
+static void smbd_free_send_io(struct smbdirect_send_io *msg)
+{
+	struct smbdirect_socket *sc = msg->socket;
+	size_t i;
+
+	/*
+	 * The list needs to be empty!
+	 * The caller should take care of it.
+	 */
+	WARN_ON_ONCE(!list_empty(&msg->sibling_list));
+
+	/*
+	 * Note we call ib_dma_unmap_page(), even if some sges are mapped using
+	 * ib_dma_map_single().
+	 *
+	 * The difference between _single() and _page() only matters for the
+	 * ib_dma_map_*() case.
+	 *
+	 * For the ib_dma_unmap_*() case it does not matter as both take the
+	 * dma_addr_t and dma_unmap_single_attrs() is just an alias to
+	 * dma_unmap_page_attrs().
+	 */
+	for (i = 0; i < msg->num_sge; i++)
+		ib_dma_unmap_page(sc->ib.dev,
+				  msg->sge[i].addr,
+				  msg->sge[i].length,
+				  DMA_TO_DEVICE);
+
+	mempool_free(msg, sc->send_io.mem.pool);
+}
+
 /* Called when a RDMA send is done */
 static void send_done(struct ib_cq *cq, struct ib_wc *wc)
 {
-	int i;
 	struct smbdirect_send_io *request =
 		container_of(wc->wr_cqe, struct smbdirect_send_io, cqe);
 	struct smbdirect_socket *sc = request->socket;
@@ -505,12 +549,8 @@ static void send_done(struct ib_cq *cq, struct ib_wc *wc)
 	log_rdma_send(INFO, "smbdirect_send_io 0x%p completed wc->status=%s\n",
 		request, ib_wc_status_msg(wc->status));
 
-	for (i = 0; i < request->num_sge; i++)
-		ib_dma_unmap_single(sc->ib.dev,
-			request->sge[i].addr,
-			request->sge[i].length,
-			DMA_TO_DEVICE);
-	mempool_free(request, sc->send_io.mem.pool);
+	/* Note this frees wc->wr_cqe, but not wc */
+	smbd_free_send_io(request);
 	lcredits += 1;
 
 	if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_SEND) {
@@ -963,15 +1003,13 @@ static int smbd_post_send_negotiate_req(struct smbdirect_socket *sc)
 {
 	struct smbdirect_socket_parameters *sp = &sc->parameters;
 	struct ib_send_wr send_wr;
-	int rc = -ENOMEM;
+	int rc;
 	struct smbdirect_send_io *request;
 	struct smbdirect_negotiate_req *packet;
 
-	request = mempool_alloc(sc->send_io.mem.pool, GFP_KERNEL);
-	if (!request)
-		return rc;
-
-	request->socket = sc;
+	request = smbd_alloc_send_io(sc);
+	if (IS_ERR(request))
+		return PTR_ERR(request);
 
 	packet = smbdirect_send_io_payload(request);
 	packet->min_version = cpu_to_le16(SMBDIRECT_V1);
@@ -983,7 +1021,6 @@ static int smbd_post_send_negotiate_req(struct smbdirect_socket *sc)
 	packet->max_fragmented_size =
 		cpu_to_le32(sp->max_fragmented_recv_size);
 
-	request->num_sge = 1;
 	request->sge[0].addr = ib_dma_map_single(
 				sc->ib.dev, (void *)packet,
 				sizeof(*packet), DMA_TO_DEVICE);
@@ -991,6 +1028,7 @@ static int smbd_post_send_negotiate_req(struct smbdirect_socket *sc)
 		rc = -EIO;
 		goto dma_mapping_failed;
 	}
+	request->num_sge = 1;
 
 	request->sge[0].length = sizeof(*packet);
 	request->sge[0].lkey = sc->ib.pd->local_dma_lkey;
@@ -1020,13 +1058,11 @@ static int smbd_post_send_negotiate_req(struct smbdirect_socket *sc)
 	/* if we reach here, post send failed */
 	log_rdma_send(ERR, "ib_post_send failed rc=%d\n", rc);
 	atomic_dec(&sc->send_io.pending.count);
-	ib_dma_unmap_single(sc->ib.dev, request->sge[0].addr,
-		request->sge[0].length, DMA_TO_DEVICE);
 
 	smbd_disconnect_rdma_connection(sc);
 
 dma_mapping_failed:
-	mempool_free(request, sc->send_io.mem.pool);
+	smbd_free_send_io(request);
 	return rc;
 }
 
@@ -1187,7 +1223,7 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 			       int *_remaining_data_length)
 {
 	struct smbdirect_socket_parameters *sp = &sc->parameters;
-	int i, rc;
+	int rc;
 	int header_length;
 	int data_length;
 	struct smbdirect_send_io *request;
@@ -1208,13 +1244,12 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 		goto err_wait_credit;
 	}
 
-	request = mempool_alloc(sc->send_io.mem.pool, GFP_KERNEL);
-	if (!request) {
-		rc = -ENOMEM;
+	request = smbd_alloc_send_io(sc);
+	if (IS_ERR(request)) {
+		rc = PTR_ERR(request);
 		goto err_alloc;
 	}
 
-	request->socket = sc;
 	memset(request->sge, 0, sizeof(request->sge));
 
 	/* Map the packet to DMA */
@@ -1292,13 +1327,7 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 		return 0;
 
 err_dma:
-	for (i = 0; i < request->num_sge; i++)
-		if (request->sge[i].addr)
-			ib_dma_unmap_single(sc->ib.dev,
-					    request->sge[i].addr,
-					    request->sge[i].length,
-					    DMA_TO_DEVICE);
-	mempool_free(request, sc->send_io.mem.pool);
+	smbd_free_send_io(request);
 
 err_alloc:
 	atomic_inc(&sc->send_io.credits.count);
-- 
2.53.0

[PATCH 6.18 22/49] smb: client: use smbdirect_send_batch processing

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 2c1ac39ce9cd4112f406775c626eef7f3eb4c481 upstream.

This will allow us to use similar logic as we have in
the server soon, so that we can share common code later.

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 | 149 ++++++++++++++++++++++++++++++++++----
 1 file changed, 135 insertions(+), 14 deletions(-)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index 6cb40da7e589..ef3b237bccc1 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -544,11 +544,20 @@ static void send_done(struct ib_cq *cq, struct ib_wc *wc)
 	struct smbdirect_send_io *request =
 		container_of(wc->wr_cqe, struct smbdirect_send_io, cqe);
 	struct smbdirect_socket *sc = request->socket;
+	struct smbdirect_send_io *sibling, *next;
 	int lcredits = 0;
 
 	log_rdma_send(INFO, "smbdirect_send_io 0x%p completed wc->status=%s\n",
 		request, ib_wc_status_msg(wc->status));
 
+	/*
+	 * Free possible siblings and then the main send_io
+	 */
+	list_for_each_entry_safe(sibling, next, &request->sibling_list, sibling_list) {
+		list_del_init(&sibling->sibling_list);
+		smbd_free_send_io(sibling);
+		lcredits += 1;
+	}
 	/* Note this frees wc->wr_cqe, but not wc */
 	smbd_free_send_io(request);
 	lcredits += 1;
@@ -1154,7 +1163,8 @@ static int smbd_ib_post_send(struct smbdirect_socket *sc,
 
 /* Post the send request */
 static int smbd_post_send(struct smbdirect_socket *sc,
-		struct smbdirect_send_io *request)
+			  struct smbdirect_send_batch *batch,
+			  struct smbdirect_send_io *request)
 {
 	int i;
 
@@ -1170,16 +1180,95 @@ static int smbd_post_send(struct smbdirect_socket *sc,
 	}
 
 	request->cqe.done = send_done;
-
 	request->wr.next = NULL;
-	request->wr.wr_cqe = &request->cqe;
 	request->wr.sg_list = request->sge;
 	request->wr.num_sge = request->num_sge;
 	request->wr.opcode = IB_WR_SEND;
+
+	if (batch) {
+		request->wr.wr_cqe = NULL;
+		request->wr.send_flags = 0;
+		if (!list_empty(&batch->msg_list)) {
+			struct smbdirect_send_io *last;
+
+			last = list_last_entry(&batch->msg_list,
+					       struct smbdirect_send_io,
+					       sibling_list);
+			last->wr.next = &request->wr;
+		}
+		list_add_tail(&request->sibling_list, &batch->msg_list);
+		batch->wr_cnt++;
+		return 0;
+	}
+
+	request->wr.wr_cqe = &request->cqe;
 	request->wr.send_flags = IB_SEND_SIGNALED;
 	return smbd_ib_post_send(sc, &request->wr);
 }
 
+static void smbd_send_batch_init(struct smbdirect_send_batch *batch,
+				 bool need_invalidate_rkey,
+				 unsigned int remote_key)
+{
+	INIT_LIST_HEAD(&batch->msg_list);
+	batch->wr_cnt = 0;
+	batch->need_invalidate_rkey = need_invalidate_rkey;
+	batch->remote_key = remote_key;
+}
+
+static int smbd_send_batch_flush(struct smbdirect_socket *sc,
+				 struct smbdirect_send_batch *batch,
+				 bool is_last)
+{
+	struct smbdirect_send_io *first, *last;
+	int ret = 0;
+
+	if (list_empty(&batch->msg_list))
+		return 0;
+
+	first = list_first_entry(&batch->msg_list,
+				 struct smbdirect_send_io,
+				 sibling_list);
+	last = list_last_entry(&batch->msg_list,
+			       struct smbdirect_send_io,
+			       sibling_list);
+
+	if (batch->need_invalidate_rkey) {
+		first->wr.opcode = IB_WR_SEND_WITH_INV;
+		first->wr.ex.invalidate_rkey = batch->remote_key;
+		batch->need_invalidate_rkey = false;
+		batch->remote_key = 0;
+	}
+
+	last->wr.send_flags = IB_SEND_SIGNALED;
+	last->wr.wr_cqe = &last->cqe;
+
+	/*
+	 * Remove last from batch->msg_list
+	 * and splice the rest of batch->msg_list
+	 * to last->sibling_list.
+	 *
+	 * batch->msg_list is a valid empty list
+	 * at the end.
+	 */
+	list_del_init(&last->sibling_list);
+	list_splice_tail_init(&batch->msg_list, &last->sibling_list);
+	batch->wr_cnt = 0;
+
+	ret = smbd_ib_post_send(sc, &first->wr);
+	if (ret) {
+		struct smbdirect_send_io *sibling, *next;
+
+		list_for_each_entry_safe(sibling, next, &last->sibling_list, sibling_list) {
+			list_del_init(&sibling->sibling_list);
+			smbd_free_send_io(sibling);
+		}
+		smbd_free_send_io(last);
+	}
+
+	return ret;
+}
+
 static int wait_for_credits(struct smbdirect_socket *sc,
 			    wait_queue_head_t *waitq, atomic_t *total_credits,
 			    int needed)
@@ -1202,16 +1291,35 @@ static int wait_for_credits(struct smbdirect_socket *sc,
 	} while (true);
 }
 
-static int wait_for_send_lcredit(struct smbdirect_socket *sc)
+static int wait_for_send_lcredit(struct smbdirect_socket *sc,
+				 struct smbdirect_send_batch *batch)
 {
+	if (batch && (atomic_read(&sc->send_io.lcredits.count) <= 1)) {
+		int ret;
+
+		ret = smbd_send_batch_flush(sc, batch, false);
+		if (ret)
+			return ret;
+	}
+
 	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)
+static int wait_for_send_credits(struct smbdirect_socket *sc,
+				 struct smbdirect_send_batch *batch)
 {
+	if (batch &&
+	    (batch->wr_cnt >= 16 || atomic_read(&sc->send_io.credits.count) <= 1)) {
+		int ret;
+
+		ret = smbd_send_batch_flush(sc, batch, false);
+		if (ret)
+			return ret;
+	}
+
 	return wait_for_credits(sc,
 				&sc->send_io.credits.wait_queue,
 				&sc->send_io.credits.count,
@@ -1219,6 +1327,7 @@ static int wait_for_send_credits(struct smbdirect_socket *sc)
 }
 
 static int smbd_post_send_iter(struct smbdirect_socket *sc,
+			       struct smbdirect_send_batch *batch,
 			       struct iov_iter *iter,
 			       int *_remaining_data_length)
 {
@@ -1230,14 +1339,14 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 	struct smbdirect_data_transfer *packet;
 	int new_credits = 0;
 
-	rc = wait_for_send_lcredit(sc);
+	rc = wait_for_send_lcredit(sc, batch);
 	if (rc) {
 		log_outgoing(ERR, "disconnected not sending on wait_lcredit\n");
 		rc = -EAGAIN;
 		goto err_wait_lcredit;
 	}
 
-	rc = wait_for_send_credits(sc);
+	rc = wait_for_send_credits(sc, batch);
 	if (rc) {
 		log_outgoing(ERR, "disconnected not sending on wait_credit\n");
 		rc = -EAGAIN;
@@ -1322,7 +1431,7 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 		     le32_to_cpu(packet->data_length),
 		     le32_to_cpu(packet->remaining_data_length));
 
-	rc = smbd_post_send(sc, request);
+	rc = smbd_post_send(sc, batch, request);
 	if (!rc)
 		return 0;
 
@@ -1351,10 +1460,11 @@ static int smbd_post_send_empty(struct smbdirect_socket *sc)
 	int remaining_data_length = 0;
 
 	sc->statistics.send_empty++;
-	return smbd_post_send_iter(sc, NULL, &remaining_data_length);
+	return smbd_post_send_iter(sc, NULL, NULL, &remaining_data_length);
 }
 
 static int smbd_post_send_full_iter(struct smbdirect_socket *sc,
+				    struct smbdirect_send_batch *batch,
 				    struct iov_iter *iter,
 				    int *_remaining_data_length)
 {
@@ -1367,7 +1477,7 @@ static int smbd_post_send_full_iter(struct smbdirect_socket *sc,
 	 */
 
 	while (iov_iter_count(iter) > 0) {
-		rc = smbd_post_send_iter(sc, iter, _remaining_data_length);
+		rc = smbd_post_send_iter(sc, batch, iter, _remaining_data_length);
 		if (rc < 0)
 			break;
 	}
@@ -2289,8 +2399,10 @@ int smbd_send(struct TCP_Server_Info *server,
 	struct smbdirect_socket_parameters *sp = &sc->parameters;
 	struct smb_rqst *rqst;
 	struct iov_iter iter;
+	struct smbdirect_send_batch batch;
 	unsigned int remaining_data_length, klen;
 	int rc, i, rqst_idx;
+	int error = 0;
 
 	if (sc->status != SMBDIRECT_SOCKET_CONNECTED)
 		return -EAGAIN;
@@ -2315,6 +2427,7 @@ int smbd_send(struct TCP_Server_Info *server,
 			num_rqst, remaining_data_length);
 
 	rqst_idx = 0;
+	smbd_send_batch_init(&batch, false, 0);
 	do {
 		rqst = &rqst_array[rqst_idx];
 
@@ -2333,20 +2446,28 @@ int smbd_send(struct TCP_Server_Info *server,
 			klen += rqst->rq_iov[i].iov_len;
 		iov_iter_kvec(&iter, ITER_SOURCE, rqst->rq_iov, rqst->rq_nvec, klen);
 
-		rc = smbd_post_send_full_iter(sc, &iter, &remaining_data_length);
-		if (rc < 0)
+		rc = smbd_post_send_full_iter(sc, &batch, &iter, &remaining_data_length);
+		if (rc < 0) {
+			error = rc;
 			break;
+		}
 
 		if (iov_iter_count(&rqst->rq_iter) > 0) {
 			/* And then the data pages if there are any */
-			rc = smbd_post_send_full_iter(sc, &rqst->rq_iter,
+			rc = smbd_post_send_full_iter(sc, &batch, &rqst->rq_iter,
 						      &remaining_data_length);
-			if (rc < 0)
+			if (rc < 0) {
+				error = rc;
 				break;
+			}
 		}
 
 	} while (++rqst_idx < num_rqst);
 
+	rc = smbd_send_batch_flush(sc, &batch, true);
+	if (unlikely(!rc && error))
+		rc = error;
+
 	/*
 	 * As an optimization, we don't wait for individual I/O to finish
 	 * before sending the next one.
-- 
2.53.0

[PATCH 6.18 23/49] smb: client: make use of smbdirect_socket.send_io.bcredits

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 21538121efe6c8c5b51c742fa02cbe820bc48714 upstream.

It turns out that our code will corrupt the stream of
reassabled data transfer messages when we trigger an
immendiate (empty) send.

In order to fix this we'll have a single 'batch' credit per
connection. And code getting that credit is free to use
as much messages until remaining_length reaches 0, then
the batch credit it given back and the next logical send can
happen.

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 | 58 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 55 insertions(+), 3 deletions(-)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index ef3b237bccc1..dbb2d939bc44 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -657,6 +657,7 @@ static bool process_negotiation_response(
 			sp->max_frmr_depth * PAGE_SIZE);
 	sp->max_frmr_depth = sp->max_read_write_size / PAGE_SIZE;
 
+	atomic_set(&sc->send_io.bcredits.count, 1);
 	sc->recv_io.expected = SMBDIRECT_EXPECT_DATA_TRANSFER;
 	return true;
 }
@@ -1214,6 +1215,7 @@ static void smbd_send_batch_init(struct smbdirect_send_batch *batch,
 	batch->wr_cnt = 0;
 	batch->need_invalidate_rkey = need_invalidate_rkey;
 	batch->remote_key = remote_key;
+	batch->credit = 0;
 }
 
 static int smbd_send_batch_flush(struct smbdirect_socket *sc,
@@ -1224,7 +1226,7 @@ static int smbd_send_batch_flush(struct smbdirect_socket *sc,
 	int ret = 0;
 
 	if (list_empty(&batch->msg_list))
-		return 0;
+		goto release_credit;
 
 	first = list_first_entry(&batch->msg_list,
 				 struct smbdirect_send_io,
@@ -1266,6 +1268,13 @@ static int smbd_send_batch_flush(struct smbdirect_socket *sc,
 		smbd_free_send_io(last);
 	}
 
+release_credit:
+	if (is_last && !ret && batch->credit) {
+		atomic_add(batch->credit, &sc->send_io.bcredits.count);
+		batch->credit = 0;
+		wake_up(&sc->send_io.bcredits.wait_queue);
+	}
+
 	return ret;
 }
 
@@ -1291,6 +1300,25 @@ static int wait_for_credits(struct smbdirect_socket *sc,
 	} while (true);
 }
 
+static int wait_for_send_bcredit(struct smbdirect_socket *sc,
+				 struct smbdirect_send_batch *batch)
+{
+	int ret;
+
+	if (batch->credit)
+		return 0;
+
+	ret = wait_for_credits(sc,
+			       &sc->send_io.bcredits.wait_queue,
+			       &sc->send_io.bcredits.count,
+			       1);
+	if (ret)
+		return ret;
+
+	batch->credit = 1;
+	return 0;
+}
+
 static int wait_for_send_lcredit(struct smbdirect_socket *sc,
 				 struct smbdirect_send_batch *batch)
 {
@@ -1338,6 +1366,19 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 	struct smbdirect_send_io *request;
 	struct smbdirect_data_transfer *packet;
 	int new_credits = 0;
+	struct smbdirect_send_batch _batch;
+
+	if (!batch) {
+		smbd_send_batch_init(&_batch, false, 0);
+		batch = &_batch;
+	}
+
+	rc = wait_for_send_bcredit(sc, batch);
+	if (rc) {
+		log_outgoing(ERR, "disconnected not sending on wait_bcredit\n");
+		rc = -EAGAIN;
+		goto err_wait_bcredit;
+	}
 
 	rc = wait_for_send_lcredit(sc, batch);
 	if (rc) {
@@ -1432,8 +1473,14 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 		     le32_to_cpu(packet->remaining_data_length));
 
 	rc = smbd_post_send(sc, batch, request);
-	if (!rc)
-		return 0;
+	if (!rc) {
+		if (batch != &_batch)
+			return 0;
+
+		rc = smbd_send_batch_flush(sc, batch, true);
+		if (!rc)
+			return 0;
+	}
 
 err_dma:
 	smbd_free_send_io(request);
@@ -1447,6 +1494,11 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 	wake_up(&sc->send_io.lcredits.wait_queue);
 
 err_wait_lcredit:
+	atomic_add(batch->credit, &sc->send_io.bcredits.count);
+	batch->credit = 0;
+	wake_up(&sc->send_io.bcredits.wait_queue);
+
+err_wait_bcredit:
 	return rc;
 }
 
-- 
2.53.0

[PATCH 6.18 24/49] smb: client: fix last send credit problem causing disconnects

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 93ac432274e1361b4f6cd69e7c5d9b3ac21e13f5 upstream.

When we are about to use the last send credit that was
granted to us by the peer, we need to wait until
we are ourself able to grant at least one credit
to the peer. Otherwise it might not be possible
for the peer to grant more credits.

The following sections in MS-SMBD are related to this:

3.1.5.1 Sending Upper Layer Messages
...
If Connection.SendCredits is 1 and the CreditsGranted field of the
message is 0, stop processing.
...

3.1.5.9 Managing Credits Prior to Sending
...
If Connection.ReceiveCredits is zero, or if Connection.SendCredits is
one and the Connection.SendQueue is not empty, the sender MUST allocate
and post at least one receive of size Connection.MaxReceiveSize and MUST
increment Connection.ReceiveCredits by the number allocated and posted.
If no receives are posted, the processing MUST return a value of zero to
indicate to the caller that no Send message can be currently performed.
...

This is a similar logic as we have in the server.

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 | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index dbb2d939bc44..20faa6d7f514 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -697,6 +697,15 @@ static void smbd_post_send_credits(struct work_struct *work)
 
 	atomic_add(posted, &sc->recv_io.credits.available);
 
+	/*
+	 * If the last send credit is waiting for credits
+	 * it can grant we need to wake it up
+	 */
+	if (posted &&
+	    atomic_read(&sc->send_io.bcredits.count) == 0 &&
+	    atomic_read(&sc->send_io.credits.count) == 0)
+		wake_up(&sc->send_io.credits.wait_queue);
+
 	/* Promptly send an immediate packet as defined in [MS-SMBD] 3.1.1.1 */
 	if (atomic_read(&sc->recv_io.credits.count) <
 		sc->recv_io.credits.target - 1) {
@@ -1394,6 +1403,26 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 		goto err_wait_credit;
 	}
 
+	new_credits = manage_credits_prior_sending(sc);
+	if (new_credits == 0 &&
+	    atomic_read(&sc->send_io.credits.count) == 0 &&
+	    atomic_read(&sc->recv_io.credits.count) == 0) {
+		queue_work(sc->workqueue, &sc->recv_io.posted.refill_work);
+		rc = wait_event_interruptible(sc->send_io.credits.wait_queue,
+					      atomic_read(&sc->send_io.credits.count) >= 1 ||
+					      atomic_read(&sc->recv_io.credits.available) >= 1 ||
+					      sc->status != SMBDIRECT_SOCKET_CONNECTED);
+		if (sc->status != SMBDIRECT_SOCKET_CONNECTED)
+			rc = -ENOTCONN;
+		if (rc < 0) {
+			log_outgoing(ERR, "disconnected not sending on last credit\n");
+			rc = -EAGAIN;
+			goto err_wait_credit;
+		}
+
+		new_credits = manage_credits_prior_sending(sc);
+	}
+
 	request = smbd_alloc_send_io(sc);
 	if (IS_ERR(request)) {
 		rc = PTR_ERR(request);
@@ -1448,8 +1477,6 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
 
 	/* Fill in the packet header */
 	packet->credits_requested = cpu_to_le16(sp->send_credit_target);
-
-	new_credits = manage_credits_prior_sending(sc);
 	packet->credits_granted = cpu_to_le16(new_credits);
 
 	packet->flags = 0;
-- 
2.53.0

[PATCH 6.18 25/49] smb: client: let smbd_post_send_negotiate_req() use smbd_post_send()

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit 5b1c6149657af840a02885135c700ab42e6aa322 upstream.

The server has similar logic and it makes sure that
request->wr is used instead of a stack struct ib_send_wr send_wr.

This makes sure send_done can see request->wr.send_flags
as the next commit will check for IB_SEND_SIGNALED

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 | 32 +++++++-------------------------
 1 file changed, 7 insertions(+), 25 deletions(-)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index 20faa6d7f514..88fefb901c27 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -35,6 +35,10 @@ static void enqueue_reassembly(
 static struct smbdirect_recv_io *_get_first_reassembly(
 		struct smbdirect_socket *sc);
 
+static int smbd_post_send(struct smbdirect_socket *sc,
+			  struct smbdirect_send_batch *batch,
+			  struct smbdirect_send_io *request);
+
 static int smbd_post_recv(
 		struct smbdirect_socket *sc,
 		struct smbdirect_recv_io *response);
@@ -1021,7 +1025,6 @@ static int smbd_ia_open(
 static int smbd_post_send_negotiate_req(struct smbdirect_socket *sc)
 {
 	struct smbdirect_socket_parameters *sp = &sc->parameters;
-	struct ib_send_wr send_wr;
 	int rc;
 	struct smbdirect_send_io *request;
 	struct smbdirect_negotiate_req *packet;
@@ -1052,33 +1055,12 @@ static int smbd_post_send_negotiate_req(struct smbdirect_socket *sc)
 	request->sge[0].length = sizeof(*packet);
 	request->sge[0].lkey = sc->ib.pd->local_dma_lkey;
 
-	ib_dma_sync_single_for_device(
-		sc->ib.dev, request->sge[0].addr,
-		request->sge[0].length, DMA_TO_DEVICE);
-
-	request->cqe.done = send_done;
-
-	send_wr.next = NULL;
-	send_wr.wr_cqe = &request->cqe;
-	send_wr.sg_list = request->sge;
-	send_wr.num_sge = request->num_sge;
-	send_wr.opcode = IB_WR_SEND;
-	send_wr.send_flags = IB_SEND_SIGNALED;
-
-	log_rdma_send(INFO, "sge addr=0x%llx length=%u lkey=0x%x\n",
-		request->sge[0].addr,
-		request->sge[0].length, request->sge[0].lkey);
-
-	atomic_inc(&sc->send_io.pending.count);
-	rc = ib_post_send(sc->ib.qp, &send_wr, NULL);
+	rc = smbd_post_send(sc, NULL, request);
 	if (!rc)
 		return 0;
 
-	/* if we reach here, post send failed */
-	log_rdma_send(ERR, "ib_post_send failed rc=%d\n", rc);
-	atomic_dec(&sc->send_io.pending.count);
-
-	smbd_disconnect_rdma_connection(sc);
+	if (rc == -EAGAIN)
+		rc = -EIO;
 
 dma_mapping_failed:
 	smbd_free_send_io(request);
-- 
2.53.0

[PATCH 6.18 26/49] smb: client: let send_done handle a completion without IB_SEND_SIGNALED

[Greg Kroah-Hartman]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stefan Metzmacher <metze@samba.org>

commit cf74fcdc43b322b6188a0750b5ee79e38be6d078 upstream.

With smbdirect_send_batch processing we likely have requests without
IB_SEND_SIGNALED, which will be destroyed in the final request
that has IB_SEND_SIGNALED set.

If the connection is broken all requests are signaled
even without explicit IB_SEND_SIGNALED.

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 | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index 88fefb901c27..01d55bcc6d0f 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -554,6 +554,32 @@ static void send_done(struct ib_cq *cq, struct ib_wc *wc)
 	log_rdma_send(INFO, "smbdirect_send_io 0x%p completed wc->status=%s\n",
 		request, ib_wc_status_msg(wc->status));
 
+	if (unlikely(!(request->wr.send_flags & IB_SEND_SIGNALED))) {
+		/*
+		 * This happens when smbdirect_send_io is a sibling
+		 * before the final message, it is signaled on
+		 * error anyway, so we need to skip
+		 * smbdirect_connection_free_send_io here,
+		 * otherwise is will destroy the memory
+		 * of the siblings too, which will cause
+		 * use after free problems for the others
+		 * triggered from ib_drain_qp().
+		 */
+		if (wc->status != IB_WC_SUCCESS)
+			goto skip_free;
+
+		/*
+		 * This should not happen!
+		 * But we better just close the
+		 * connection...
+		 */
+		log_rdma_send(ERR,
+			"unexpected send completion wc->status=%s (%d) wc->opcode=%d\n",
+			ib_wc_status_msg(wc->status), wc->status, wc->opcode);
+		smbd_disconnect_rdma_connection(sc);
+		return;
+	}
+
 	/*
 	 * Free possible siblings and then the main send_io
 	 */
@@ -567,6 +593,7 @@ static void send_done(struct ib_cq *cq, struct ib_wc *wc)
 	lcredits += 1;
 
 	if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_SEND) {
+skip_free:
 		if (wc->status != IB_WC_WR_FLUSH_ERR)
 			log_rdma_send(ERR, "wc->status=%s wc->opcode=%d\n",
 				ib_wc_status_msg(wc->status), wc->opcode);
-- 
2.53.0