Commit 21538121 authored by Stefan Metzmacher's avatar Stefan Metzmacher Committed by Steve French
Browse files

smb: client: make use of smbdirect_socket.send_io.bcredits 



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: default avatarStefan Metzmacher <metze@samba.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 2c1ac39c

fs/smb/client/smbdirect.c

+55 −3
Original line number Diff line number Diff line
@@ -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) {

		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;

}