CIFS: Respect reconnect in non-MTU credits calculations

Every time after a session reconnect we don't need to account for
credits obtained in previous sessions. Make use of the recently
added cifs_credits structure to properly calculate credits for
non-MTU requests the same way we did for MTU ones.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

4 files changed, 64 insertions, 38 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 4293b1f13f00..84ce388de89d 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -741,12 +741,10 @@ has_credits(struct TCP_Server_Info *server, int *credits)
 }
 
 static inline void
-add_credits(struct TCP_Server_Info *server, const unsigned int add,
+add_credits(struct TCP_Server_Info *server, const struct cifs_credits *credits,
 	    const int optype)
 {
-	struct cifs_credits credits = { .value = add, .instance = 0 };
-
-	server->ops->add_credits(server, &credits, optype);
+	server->ops->add_credits(server, credits, optype);
 }
 
 static inline void
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 3f4e40abaad4..d4f94406a808 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -822,9 +822,10 @@ static void
 cifs_echo_callback(struct mid_q_entry *mid)
 {
 	struct TCP_Server_Info *server = mid->callback_data;
+	struct cifs_credits credits = { .value = 1, .instance = 0 };
 
 	DeleteMidQEntry(mid);
-	add_credits(server, 1, CIFS_ECHO_OP);
+	add_credits(server, &credits, CIFS_ECHO_OP);
 }
 
 int
@@ -1714,6 +1715,7 @@ cifs_readv_callback(struct mid_q_entry *mid)
 				 .rq_npages = rdata->nr_pages,
 				 .rq_pagesz = rdata->pagesz,
 				 .rq_tailsz = rdata->tailsz };
+	struct cifs_credits credits = { .value = 1, .instance = 0 };
 
 	cifs_dbg(FYI, "%s: mid=%llu state=%d result=%d bytes=%u\n",
 		 __func__, mid->mid, mid->mid_state, rdata->result,
@@ -1751,7 +1753,7 @@ cifs_readv_callback(struct mid_q_entry *mid)
 
 	queue_work(cifsiod_wq, &rdata->work);
 	DeleteMidQEntry(mid);
-	add_credits(server, 1, 0);
+	add_credits(server, &credits, 0);
 }
 
 /* cifs_async_readv - send an async write, and set up mid to handle result */
@@ -2236,6 +2238,7 @@ cifs_writev_callback(struct mid_q_entry *mid)
 	struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
 	unsigned int written;
 	WRITE_RSP *smb = (WRITE_RSP *)mid->resp_buf;
+	struct cifs_credits credits = { .value = 1, .instance = 0 };
 
 	switch (mid->mid_state) {
 	case MID_RESPONSE_RECEIVED:
@@ -2271,7 +2274,7 @@ cifs_writev_callback(struct mid_q_entry *mid)
 
 	queue_work(cifsiod_wq, &wdata->work);
 	DeleteMidQEntry(mid);
-	add_credits(tcon->ses->server, 1, 0);
+	add_credits(tcon->ses->server, &credits, 0);
 }
 
 /* cifs_async_writev - send an async write, and set up mid to handle result */
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 04581f06f29f..7d8f1d234906 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2933,14 +2933,16 @@ smb2_echo_callback(struct mid_q_entry *mid)
 {
 	struct TCP_Server_Info *server = mid->callback_data;
 	struct smb2_echo_rsp *rsp = (struct smb2_echo_rsp *)mid->resp_buf;
-	unsigned int credits_received = 0;
+	struct cifs_credits credits = { .value = 0, .instance = 0 };
 
 	if (mid->mid_state == MID_RESPONSE_RECEIVED
-	    || mid->mid_state == MID_RESPONSE_MALFORMED)
-		credits_received = le16_to_cpu(rsp->sync_hdr.CreditRequest);
+	    || mid->mid_state == MID_RESPONSE_MALFORMED) {
+		credits.value = le16_to_cpu(rsp->sync_hdr.CreditRequest);
+		credits.instance = server->reconnect_instance;
+	}
 
 	DeleteMidQEntry(mid);
-	add_credits(server, credits_received, CIFS_ECHO_OP);
+	add_credits(server, &credits, CIFS_ECHO_OP);
 }
 
 void smb2_reconnect_server(struct work_struct *work)
@@ -3193,7 +3195,7 @@ smb2_readv_callback(struct mid_q_entry *mid)
 	struct TCP_Server_Info *server = tcon->ses->server;
 	struct smb2_sync_hdr *shdr =
 				(struct smb2_sync_hdr *)rdata->iov[0].iov_base;
-	unsigned int credits_received = 0;
+	struct cifs_credits credits = { .value = 0, .instance = 0 };
 	struct smb_rqst rqst = { .rq_iov = rdata->iov,
 				 .rq_nvec = 2,
 				 .rq_pages = rdata->pages,
@@ -3208,7 +3210,8 @@ smb2_readv_callback(struct mid_q_entry *mid)
 
 	switch (mid->mid_state) {
 	case MID_RESPONSE_RECEIVED:
-		credits_received = le16_to_cpu(shdr->CreditRequest);
+		credits.value = le16_to_cpu(shdr->CreditRequest);
+		credits.instance = server->reconnect_instance;
 		/* result already set, check signature */
 		if (server->sign && !mid->decrypted) {
 			int rc;
@@ -3233,7 +3236,8 @@ smb2_readv_callback(struct mid_q_entry *mid)
 		cifs_stats_bytes_read(tcon, rdata->got_bytes);
 		break;
 	case MID_RESPONSE_MALFORMED:
-		credits_received = le16_to_cpu(shdr->CreditRequest);
+		credits.value = le16_to_cpu(shdr->CreditRequest);
+		credits.instance = server->reconnect_instance;
 		/* fall through */
 	default:
 		rdata->result = -EIO;
@@ -3263,7 +3267,7 @@ smb2_readv_callback(struct mid_q_entry *mid)
 
 	queue_work(cifsiod_wq, &rdata->work);
 	DeleteMidQEntry(mid);
-	add_credits(server, credits_received, 0);
+	add_credits(server, &credits, 0);
 }
 
 /* smb2_async_readv - send an async read, and set up mid to handle result */
@@ -3435,14 +3439,16 @@ smb2_writev_callback(struct mid_q_entry *mid)
 {
 	struct cifs_writedata *wdata = mid->callback_data;
 	struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
+	struct TCP_Server_Info *server = tcon->ses->server;
 	unsigned int written;
 	struct smb2_write_rsp *rsp = (struct smb2_write_rsp *)mid->resp_buf;
-	unsigned int credits_received = 0;
+	struct cifs_credits credits = { .value = 0, .instance = 0 };
 
 	switch (mid->mid_state) {
 	case MID_RESPONSE_RECEIVED:
-		credits_received = le16_to_cpu(rsp->sync_hdr.CreditRequest);
-		wdata->result = smb2_check_receive(mid, tcon->ses->server, 0);
+		credits.value = le16_to_cpu(rsp->sync_hdr.CreditRequest);
+		credits.instance = server->reconnect_instance;
+		wdata->result = smb2_check_receive(mid, server, 0);
 		if (wdata->result != 0)
 			break;
 
@@ -3466,7 +3472,8 @@ smb2_writev_callback(struct mid_q_entry *mid)
 		wdata->result = -EAGAIN;
 		break;
 	case MID_RESPONSE_MALFORMED:
-		credits_received = le16_to_cpu(rsp->sync_hdr.CreditRequest);
+		credits.value = le16_to_cpu(rsp->sync_hdr.CreditRequest);
+		credits.instance = server->reconnect_instance;
 		/* fall through */
 	default:
 		wdata->result = -EIO;
@@ -3499,7 +3506,7 @@ smb2_writev_callback(struct mid_q_entry *mid)
 
 	queue_work(cifsiod_wq, &wdata->work);
 	DeleteMidQEntry(mid);
-	add_credits(tcon->ses->server, credits_received, 0);
+	add_credits(server, &credits, 0);
 }
 
 /* smb2_async_writev - send an async write, and set up mid to handle result */
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 099a1c914720..0ee36c3e66d3 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -451,15 +451,18 @@ smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
 
 static int
 wait_for_free_credits(struct TCP_Server_Info *server, const int timeout,
-		      int *credits)
+		      int *credits, unsigned int *instance)
 {
 	int rc;
 
+	*instance = 0;
+
 	spin_lock(&server->req_lock);
 	if (timeout == CIFS_ASYNC_OP) {
 		/* oplock breaks must not be held up */
 		server->in_flight++;
 		*credits -= 1;
+		*instance = server->reconnect_instance;
 		spin_unlock(&server->req_lock);
 		return 0;
 	}
@@ -489,6 +492,7 @@ wait_for_free_credits(struct TCP_Server_Info *server, const int timeout,
 			if (timeout != CIFS_BLOCKING_OP) {
 				*credits -= 1;
 				server->in_flight++;
+				*instance = server->reconnect_instance;
 			}
 			spin_unlock(&server->req_lock);
 			break;
@@ -499,7 +503,7 @@ wait_for_free_credits(struct TCP_Server_Info *server, const int timeout,
 
 static int
 wait_for_free_request(struct TCP_Server_Info *server, const int timeout,
-		      const int optype)
+		      const int optype, unsigned int *instance)
 {
 	int *val;
 
@@ -507,7 +511,7 @@ wait_for_free_request(struct TCP_Server_Info *server, const int timeout,
 	/* Since an echo is already inflight, no need to wait to send another */
 	if (*val <= 0 && optype == CIFS_ECHO_OP)
 		return -EAGAIN;
-	return wait_for_free_credits(server, timeout, val);
+	return wait_for_free_credits(server, timeout, val, instance);
 }
 
 int
@@ -608,15 +612,17 @@ cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
 	int rc, timeout, optype;
 	struct mid_q_entry *mid;
 	struct cifs_credits credits = { .value = 0, .instance = 0 };
+	unsigned int instance;
 
 	timeout = flags & CIFS_TIMEOUT_MASK;
 	optype = flags & CIFS_OP_MASK;
 
 	if ((flags & CIFS_HAS_CREDITS) == 0) {
-		rc = wait_for_free_request(server, timeout, optype);
+		rc = wait_for_free_request(server, timeout, optype, &instance);
 		if (rc)
 			return rc;
 		credits.value = 1;
+		credits.instance = instance;
 	}
 
 	mutex_lock(&server->srv_mutex);
@@ -788,8 +794,12 @@ static void
 cifs_compound_callback(struct mid_q_entry *mid)
 {
 	struct TCP_Server_Info *server = mid->server;
+	struct cifs_credits credits;
+
+	credits.value = server->ops->get_credits(mid);
+	credits.instance = server->reconnect_instance;
 
-	add_credits(server, server->ops->get_credits(mid), mid->optype);
+	add_credits(server, &credits, mid->optype);
 }
 
 static void
@@ -815,7 +825,10 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 	int timeout, optype;
 	struct mid_q_entry *midQ[MAX_COMPOUND];
 	bool cancelled_mid[MAX_COMPOUND] = {false};
-	unsigned int credits[MAX_COMPOUND] = {0};
+	struct cifs_credits credits[MAX_COMPOUND] = {
+		{ .value = 0, .instance = 0 }
+	};
+	unsigned int instance;
 	char *buf;
 
 	timeout = flags & CIFS_TIMEOUT_MASK;
@@ -841,7 +854,8 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 	 * needed anyway.
 	 */
 	for (i = 0; i < num_rqst; i++) {
-		rc = wait_for_free_request(ses->server, timeout, optype);
+		rc = wait_for_free_request(ses->server, timeout, optype,
+					   &instance);
 		if (rc) {
 			/*
 			 * We haven't sent an SMB packet to the server yet but
@@ -853,10 +867,11 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 			 * requests correctly.
 			 */
 			for (j = 0; j < i; j++)
-				add_credits(ses->server, 1, optype);
+				add_credits(ses->server, &credits[j], optype);
 			return rc;
 		}
-		credits[i] = 1;
+		credits[i].value = 1;
+		credits[i].instance = instance;
 	}
 
 	/*
@@ -877,7 +892,7 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 
 			/* Update # of requests on wire to server */
 			for (j = 0; j < num_rqst; j++)
-				add_credits(ses->server, credits[j], optype);
+				add_credits(ses->server, &credits[j], optype);
 			return PTR_ERR(midQ[i]);
 		}
 
@@ -910,7 +925,7 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 	if (rc < 0) {
 		/* Sending failed for some reason - return credits back */
 		for (i = 0; i < num_rqst; i++)
-			add_credits(ses->server, credits[i], optype);
+			add_credits(ses->server, &credits[i], optype);
 		goto out;
 	}
 
@@ -947,7 +962,7 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 				midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
 				midQ[i]->callback = cifs_cancelled_callback;
 				cancelled_mid[i] = true;
-				credits[i] = 0;
+				credits[i].value = 0;
 			}
 			spin_unlock(&GlobalMid_Lock);
 		}
@@ -1073,6 +1088,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
 	unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
 	struct kvec iov = { .iov_base = in_buf, .iov_len = len };
 	struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
+	struct cifs_credits credits = { .value = 1, .instance = 0 };
 
 	if (ses == NULL) {
 		cifs_dbg(VFS, "Null smb session\n");
@@ -1096,7 +1112,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
 		return -EIO;
 	}
 
-	rc = wait_for_free_request(ses->server, timeout, 0);
+	rc = wait_for_free_request(ses->server, timeout, 0, &credits.instance);
 	if (rc)
 		return rc;
 
@@ -1110,7 +1126,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
 	if (rc) {
 		mutex_unlock(&ses->server->srv_mutex);
 		/* Update # of requests on wire to server */
-		add_credits(ses->server, 1, 0);
+		add_credits(ses->server, &credits, 0);
 		return rc;
 	}
 
@@ -1146,7 +1162,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
 			/* no longer considered to be "in-flight" */
 			midQ->callback = DeleteMidQEntry;
 			spin_unlock(&GlobalMid_Lock);
-			add_credits(ses->server, 1, 0);
+			add_credits(ses->server, &credits, 0);
 			return rc;
 		}
 		spin_unlock(&GlobalMid_Lock);
@@ -1154,7 +1170,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
 
 	rc = cifs_sync_mid_result(midQ, ses->server);
 	if (rc != 0) {
-		add_credits(ses->server, 1, 0);
+		add_credits(ses->server, &credits, 0);
 		return rc;
 	}
 
@@ -1170,7 +1186,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
 	rc = cifs_check_receive(midQ, ses->server, 0);
 out:
 	cifs_delete_mid(midQ);
-	add_credits(ses->server, 1, 0);
+	add_credits(ses->server, &credits, 0);
 
 	return rc;
 }
@@ -1212,6 +1228,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
 	unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
 	struct kvec iov = { .iov_base = in_buf, .iov_len = len };
 	struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
+	unsigned int instance;
 
 	if (tcon == NULL || tcon->ses == NULL) {
 		cifs_dbg(VFS, "Null smb session\n");
@@ -1237,7 +1254,8 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
 		return -EIO;
 	}
 
-	rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP, 0);
+	rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP, 0,
+				   &instance);
 	if (rc)
 		return rc;