1 files changed, 34 insertions, 17 deletions

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 450c43494324..202e0e84efdd 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -783,12 +783,7 @@ cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
 }
 
 static void
-cifs_noop_callback(struct mid_q_entry *mid)
-{
-}
-
-static void
-cifs_cancelled_callback(struct mid_q_entry *mid)
+cifs_compound_callback(struct mid_q_entry *mid)
 {
 	struct TCP_Server_Info *server = mid->server;
 	unsigned int optype = mid->optype;
@@ -801,10 +796,23 @@ cifs_cancelled_callback(struct mid_q_entry *mid)
 			cifs_dbg(FYI, "Bad state for cancelled MID\n");
 	}
 
-	DeleteMidQEntry(mid);
 	add_credits(server, credits_received, optype);
 }
 
+static void
+cifs_compound_last_callback(struct mid_q_entry *mid)
+{
+	cifs_compound_callback(mid);
+	cifs_wake_up_task(mid);
+}
+
+static void
+cifs_cancelled_callback(struct mid_q_entry *mid)
+{
+	cifs_compound_callback(mid);
+	DeleteMidQEntry(mid);
+}
+
 int
 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		   const int flags, const int num_rqst, struct smb_rqst *rqst,
@@ -882,11 +890,14 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
 		midQ[i]->optype = optype;
 		/*
-		 * We don't invoke the callback compounds unless it is the last
-		 * request.
+		 * Invoke callback for every part of the compound chain
+		 * to calculate credits properly. Wake up this thread only when
+		 * the last element is received.
 		 */
 		if (i < num_rqst - 1)
-			midQ[i]->callback = cifs_noop_callback;
+			midQ[i]->callback = cifs_compound_callback;
+		else
+			midQ[i]->callback = cifs_compound_last_callback;
 	}
 	cifs_in_send_inc(ses->server);
 	rc = smb_send_rqst(ses->server, num_rqst, rqst, flags);
@@ -900,8 +911,20 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 
 	mutex_unlock(&ses->server->srv_mutex);
 
-	if (rc < 0)
+	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);
 		goto out;
+	}
+
+	/*
+	 * At this point the request is passed to the network stack - we assume
+	 * that any credits taken from the server structure on the client have
+	 * been spent and we can't return them back. Once we receive responses
+	 * we will collect credits granted by the server in the mid callbacks
+	 * and add those credits to the server structure.
+	 */
 
 	/*
 	 * Compounding is never used during session establish.
@@ -934,11 +957,6 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		}
 	}
 
-	for (i = 0; i < num_rqst; i++)
-		if (!cancelled_mid[i] && midQ[i]->resp_buf
-		    && (midQ[i]->mid_state == MID_RESPONSE_RECEIVED))
-			credits[i] = ses->server->ops->get_credits(midQ[i]);
-
 	for (i = 0; i < num_rqst; i++) {
 		if (rc < 0)
 			goto out;
@@ -997,7 +1015,6 @@ out:
 	for (i = 0; i < num_rqst; i++) {
 		if (!cancelled_mid[i])
 			cifs_delete_mid(midQ[i]);
-		add_credits(ses->server, credits[i], optype);
 	}
 
 	return rc;