cifs: add credits from unmatched responses/messages

[ Upstream commit eca00452 ]

We should add any credits granted to us from unmatched server responses.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

fs/cifs/connect.c

@@ -930,6 +930,26 @@ cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 	return 0;
 }
 
+static void
+smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
+{
+	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer;
+
+	/*
+	 * SMB1 does not use credits.
+	 */
+	if (server->vals->header_preamble_size)
+		return;
+
+	if (shdr->CreditRequest) {
+		spin_lock(&server->req_lock);
+		server->credits += le16_to_cpu(shdr->CreditRequest);
+		spin_unlock(&server->req_lock);
+		wake_up(&server->request_q);
+	}
+}
+
+
 static int
 cifs_demultiplex_thread(void *p)
 {
@@ -1059,6 +1079,7 @@ cifs_demultiplex_thread(void *p)
 			} else if (server->ops->is_oplock_break &&
 				   server->ops->is_oplock_break(bufs[i],
 								server)) {
+				smb2_add_credits_from_hdr(bufs[i], server);
 				cifs_dbg(FYI, "Received oplock break\n");
 			} else {
 				cifs_dbg(VFS, "No task to wake, unknown frame "
@@ -1070,6 +1091,7 @@ cifs_demultiplex_thread(void *p)
 				if (server->ops->dump_detail)
 					server->ops->dump_detail(bufs[i],
 								 server);
+				smb2_add_credits_from_hdr(bufs[i], server);
 				cifs_dump_mids(server);
 #endif /* CIFS_DEBUG2 */
 			}

fs/cifs/smb2misc.c

@@ -659,13 +659,6 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 	if (rsp->sync_hdr.Command != SMB2_OPLOCK_BREAK)
 		return false;
 
-	if (rsp->sync_hdr.CreditRequest) {
-		spin_lock(&server->req_lock);
-		server->credits += le16_to_cpu(rsp->sync_hdr.CreditRequest);
-		spin_unlock(&server->req_lock);
-		wake_up(&server->request_q);
-	}
-
 	if (rsp->StructureSize !=
 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
 		if (le16_to_cpu(rsp->StructureSize) == 44)